Background The decline in reproductive performance of aged hens is mainly attributed to oxidative damage in reproductive organs,hepatic lipid metabolism disorders,and intestinal microbiota dysbiosis.Glycyrrhizin(GL)ha...Background The decline in reproductive performance of aged hens is mainly attributed to oxidative damage in reproductive organs,hepatic lipid metabolism disorders,and intestinal microbiota dysbiosis.Glycyrrhizin(GL)has been proven to enhance antioxidant capacity,regulate lipid metabolism and gut microbiota in mammals,but its efficacy in hens remains unclear.Hence,this study aimed to investigate whether dietary GL supplementation improves reproductive performance in hens during the late laying stage by modulating intestinal microbiota composition,hepatic lipid metabolism and ovarian antioxidant status.Results Dietary supplementation with 100 mg/kg GL significantly improved the egg production rate,egg quality,and hatching rate in aged breeder hens(P<0.05).GL supplementation also increased the serum levels of HDLC,TP and ALB,and enhanced the antioxidant capacity in both serum and ovary(P<0.05).In addition,dietary GL elevated the serum progesterone(P4)levels by enhancing the transcription level of steroid synthesis key enzymes(CYP11A1 and 3β-HSD)in the ovary(P<0.05).Dietary GL also promoted the synthesis and transport of vitellogenin(VTG)by upregulating the VTG-Ⅱ(P<0.05)and APOV1(P=0.077)expression levels in the liver,thereby increasing the number of grade follicles and small yellow follicles.Moreover,dietary GL enhanced hepatic fatty acidβ-oxidation by upregulating PPARαand CPT-I(P<0.05),and downregulating ACC expression levels(P<0.05).In agreement,liver metabolomics analysis revealed that dietary GL supplementation significantly altered hepatic metabolism,with 389 differentially identified metabolites(P<0.05).The key metabolites(e.g.,taurocholic acid,tauroursodeoxycholic acid,nicotinuric acid,glycodeoxycholic acid(hydrate))were identified,and they were mainly functionally enriched in betaalanine metabolism nicotinate,taurine and hypotaurine metabolism(P<0.05).Finally,16S rRNA gene sequencing revealed that dietary GL reversed age-induced changes in gut microbiota composition,characterized by a significant increase in Lactobacillus abundance and a decrease in Bacteroides(P<0.05).Conclusions These results collectively demonstrate that dietary supplementation with 100 mg/kg GL improved reproductive performance by reversing age-induced changes in gut microbiota,enhancing hepatic vitellogenin synthesis,and ameliorating ovarian function in aged breeder hens.This study suggests that dietary GL is a potential strategy to improve reproductive performance in broiler breeder hens during the late laying period.展开更多
Urban forests are highly multifunctional and provide numerous ecological functions.Plant functional traits individually or jointly influence the ecological multifunctionality of tree species(TS-EMF)and can also modify...Urban forests are highly multifunctional and provide numerous ecological functions.Plant functional traits individually or jointly influence the ecological multifunctionality of tree species(TS-EMF)and can also modify TSEMF in response to environmental changes.However,there has been limited exploration of multitrait combinations for predicting TS-EMF across seasons and of trait thresholds that enhance TS-EMF.Here,for 10 dominant tree species in urban forests of Northeast China,14 traits were measured and four aboveground and three belowground ecological functions assessed in three seasons.Ecological functions and TS-EMF differed significantly throughout the seasons(P<0.05).Synergistic relationships were found between carbon sequestration and oxygen release,between cooling and humidification,and between organic carbon accumulation and nutrient cycling.Notably,aboveground multifunctionality played a leading role in TS-EMF.With seasonal changes,resource allocation shifted toward traits related to resource acquisition rather than conservation to maintain TS-EMF.The combination of traits that predicted TS-EMF varied by type,accounting for up to 66.45%of the variation.TS-EMF was primarily driven by leaf structure in spring and by nutrient accumulation in autumn.Leaf carbon content(LCC)consistently served as a stabilizing factor for predicting TS-EMF across seasons.At 36.5-36.8 mg g^(-1),LCC had its optimal effect on TS-EMF.Other traits in combination that positively influence total TS-EMF include leaf nitrogen content(3.43-3.45 mg g^(-1)),leaf phosphorus content(0.80-0.83 mg g^(-1)),and leaf area(65.86-68.43 cm^(2)).Within these specified trait thresholds,Morus alba and Quercus mongolica were identified as key species.These findings suggest that the trade-off between various ecological functions can be managed by altering plant traits across seasons.This approach could provide a theoretical foundation for enhancing the TS-EMF of urban forests through trait-based management,offering practical guidance for selecting tree species.展开更多
Background:Epidemiological studies have confirmed that longer exposure to insecticides like cypermethrin(CYP)significantly increases the risk of male reproductive toxicity.Crocus sativus L.has been recognized due to i...Background:Epidemiological studies have confirmed that longer exposure to insecticides like cypermethrin(CYP)significantly increases the risk of male reproductive toxicity.Crocus sativus L.has been recognized due to its therapeutic properties,but its exact role and molecular mechanisms in treatment of reproductive dysfunction remain unclear.Methods:During this study,36 rats were randomly divided into six groups(n=6):control,CYP-induced(60 mg/kg),standard(leuprolide 3 mg/kg)and three treatment groups receiving aqueous,ethanolic,and oil extracts(50 mg/kg or 20 mL/kg)for post-toxicity induction.Results:The finding represented that exposure of CYP significantly increased oxidative stress,disrupted testicular architecture,and markedly reduced testosterone levels(P<0.05).Importantly,Crocus sativus L.treatment alleviated these changes by increasing the expression of Nrf2(nuclear factor erythroid 2-related factor 2),restoring the activity of antioxidant enzymes,and enhancing testicular histomorphology.Surprisingly,molecular docking established a high binding affinity of Crocus sativus L.phytoconstituents such as gallic acid,cinnamic acid and quercetin to the Nrf2-Keap1 complex.It is worth noting that,Crocus sativus L.exhibited a high level of protection against reproductive toxicity caused by CYP in male rats,which was mediated by the activation of Nrf2 pathway,reduction of oxidative damage,and favorable ADMET characteristics.Conclusion:Notably,this research provides a more valid,safe,and effective method of developing new drugs for reproductive disorders,however,further investigation is needed to support the research findings and implement it in clinical practice.展开更多
The objective of this study was to set up a rhesus monkey model of polycystic ovary syndrome（PCOS）,which is globally prevalent among reproductive-aged human women,and to understand the reproductive traits of PCOS fe...The objective of this study was to set up a rhesus monkey model of polycystic ovary syndrome（PCOS）,which is globally prevalent among reproductive-aged human women,and to understand the reproductive traits of PCOS female monkeys.Six adult female rhesus monkeys aged 6-10 a,were divided into a PCOS group and a control group.The PCOS group were given two cycles of subcutaneous injections of propionic acid testosterone（PAT）,3.5 mg/kg body weight,on day 1,day 3,and day 5 of the menstrual cycle,respectively,and then given muscle injections of human chorionic gonadotropin（HCG）,350 IU/kg body wtight,on day 7,day 9,and day 11,respectively.Results showed that high levels of serum LH and T [（5.35±0.17） IU/L and（7.58±0.14） ng/mL,respectively],and a high ratio value of LH/FSH（5.35/1.30=4.12） were observed in the PCOS group.No significant differences were found in serum FSH,E2,and P in the PCOS group compared with those of the control.Polycystic ovaries in the PCOS monkeys were recorded by live ultrasound.The blastocysts rates of the PCOS vs.the control were 23.53% vs.66.67%,and there was a significant difference between the two groups.This study shows that PAT coupled with HCG can induce PCOS in rhesus monkeys in the short term.The reproductive features of PCOS monkeys were similar to those of PCOS patients.展开更多
Follicle stimulating hormone β (FSHβ) of Japanese flounder (Paralichthys olivaceus) plays a key role in the regulation of gonadal development.This study aimed to investigate molecular genetic characteristics of the ...Follicle stimulating hormone β (FSHβ) of Japanese flounder (Paralichthys olivaceus) plays a key role in the regulation of gonadal development.This study aimed to investigate molecular genetic characteristics of the FSHβ gene and elucidate the effects of single nucleotide polymorphisms (SNPs) of FSHβ on reproductive traits in Japanese flounder.We used polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and sequencing of the FSHβ gene in 60 individuals.We identified only an SNP (T/C) in the coding region of exon3 of FSHβ.The SNP (T/C) did not lead to amino acid changes at the position 340 bp of FSHβ gene.Statistical analysis showed that the SNP was significantly associated with testosterone (T) level and gonadosomatic index (GSI) (P<0.05).Individuals with genotype TC of the SNP had significantly higher serum T levels and GSI (P<0.05) than that of genotype CC.Therefore, FSHβ gene could be a useful molecular marker in selection for prominent reproductive trait in Japanese Flounder.展开更多
Conyza sumatrensis （Retz.） E. Walker, a member of Asteraceae, is a highly invasive species. However, its reproduction biology remains poorly known. To understand the role of reproductive traits in successful invasio...Conyza sumatrensis （Retz.） E. Walker, a member of Asteraceae, is a highly invasive species. However, its reproduction biology remains poorly known. To understand the role of reproductive traits in successful invasion of the species, we studied several traits of its reproductive system： the miniature capitulum and gynomonoecious sexual system, the biology and phenology of capitula and florets, pollen/ovule ratio, the mating system （selfcompatibility）, flower visitors, physical traits and dispersal potential of achenes, germination potential of achenes from manually pollinated capitula, and the association of these traits with invasiveness. Our study showed that the reproductive traits of autonomous seed production, versatile mating system of self- and cross-pollination, and generalized pollination system might contribute to the species＇ successful invasive capability. The invasiveness was further enhanced by the high and rapid production of achenes, as well as the high percentage, rapid germination rate and high dispersal capability of achenes. It was concluded that in annual or winter-annual weeds, autonomous seed production contributed significantly to the invasiveness of the species.展开更多
In this study, the heritability, repeatability, phenotypic correlation, and genetic correlation of the reproductive and growth traits of L. vannamei were investigated and estimated. Eight traits of 385 shrimps from fo...In this study, the heritability, repeatability, phenotypic correlation, and genetic correlation of the reproductive and growth traits of L. vannamei were investigated and estimated. Eight traits of 385 shrimps from forty-two families, including the number of eggs(EN), number of nauplii(NN), egg diameter(ED), spawning frequency(SF), spawning success(SS), female body weight(BW) and body length(BL) at insemination, and condition factor(K), were measured,. A total of 519 spawning records including multiple spawning and 91 no spawning records were collected. The genetic parameters were estimated using an animal model, a multinomial logit model(for SF), and a sire-dam and probit model(for SS). Because there were repeated records, permanent environmental effects were included in the models. The heritability estimates for BW, BL, EN, NN, ED, SF, SS, and K were 0.49 ± 0.14, 0.51 ± 0.14, 0.12 ± 0.08, 0, 0.01 ± 0.04, 0.06 ± 0.06, 0.18 ± 0.07, and 0.10 ± 0.06, respectively. The genetic correlation was 0.99 ± 0.01 between BW and BL, 0.90 ± 0.19 between BW and EN, 0.22 ± 0.97 between BW and ED,-0.77 ± 1.14 between EN and ED, and-0.27 ± 0.36 between BW and K. The heritability of EN estimated without a covariate was 0.12 ± 0.08, and the genetic correlation was 0.90 ± 0.19 between BW and EN, indicating that improving BW may be used in selection programs to genetically improve the reproductive output of L. vannamei during the breeding. For EN, the data were also analyzed using body weight as a covariate(EN-2). The heritability of EN-2 was 0.03 ± 0.05, indicating that it is difficult to improve the reproductive output by genetic improvement. Furthermore, excessive pursuit of this selection is often at the expense of growth speed. Therefore, the selection of high-performance spawners using BW and SS may be an important strategy to improve nauplii production.展开更多
Background： Follicle-stimulating hormone（FSH） is a gonadotropin synthesized and secreted by the pituitary gland.FSH stimulates follicle development and maturation in females. It also plays an important role in sper...Background： Follicle-stimulating hormone（FSH） is a gonadotropin synthesized and secreted by the pituitary gland.FSH stimulates follicle development and maturation in females. It also plays an important role in spermatogenesis in males, including humans and mice. However, the effects of FSH on male pigs are largely unknown. In this study,we generated transgenic pigs to investigate the effects of FSHα/β overexpression on reproductive traits in boars.Results： After five transgenic F0 founders were crossed with wide-type pigs, 193 F_1 animals were obtained. Of these,96 were confirmed as transgenic. FSHα and FSHβ m RNAs were detected only in pituitary tissue. Transgenic boars exhibited significantly higher levels of FSHα and FSHβ m RNA, serum FSH, and serum testosterone, compared to ful-sib non-transgenic boars. Significant increases in testis weight, vas deferens diameter, seminiferous tubule diameter,and the number of Leydig cel s were observed, suggesting that the exogenous FSHα/β affects reproductive traits. Final y,transgenic and non-transgenic boars had similar growth performance and biochemical profiles.Conclusions： Pituitary-specific overexpression of FSHα/β genes is likely to impact reproductive traits positively, as indicated by enhancements in serum testosterone level, testis weight, the development of vas deferens, seminiferous tubules, and Leydig cells in transgenic boars. A high level of serum FSH induces secretion of serum testosterone,possibly by boosting the number of Leydig cells, which presumably increases the libido and the frequency of sexual activity in transgenic boars. Our study provides a preliminary foundation for the genetic improvement of reproductive traits in male pigs.展开更多
Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants...Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants may be closely related to the success of the latter.Accordingly,this study examines differences in functional traits and reproductive allocation strategies between native and invasive plants in Eastern China.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants were all notably higher than those of native species.Additionally,the specific leaf area(SLA)values of invasive plants were remarkably lower than those of native species.Plasticity indexes of SLA,maximum branch angle,and branch number of invasive plants were each notably lower than those of native species.The reproductive allocation coefficient was positively correlated with reproductive branch number and the belowground-to-aboveground biomass ratio but exhibited negative correlations with SLA and aboveground biomass.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants may strongly influence the success of their invasions.展开更多
Background:Reproductive performance of livestock is an economically important aspect of global food production.The Chinese Meishan pig is a prolific breed,with an average of three to five more piglets per litter than ...Background:Reproductive performance of livestock is an economically important aspect of global food production.The Chinese Meishan pig is a prolific breed,with an average of three to five more piglets per litter than European breeds;however,the genetic basis for this difference is not well understood.Results:In this study,we investigated copy number variations(CNVs)of 32 Meishan pigs and 29 Duroc pigs by nextgeneration sequencing.A genome-wide analysis of 61 pigs revealed 12,668 copy number variable regions(CNVRs)that were further divided into three categories based on copy number(CN)of the whole population,i.e.,gain(n=7,638),and loss(n=5,030)CNVRs.We then compared Meishan and Duroc pigs and identified 17.17Mb of 6,387 CNVRs that only existing in Meishan pigs CNVRs that overlapped the reproduction-related gene encoding the aryl hydrocarbon receptor(AHR)gene.We found that normal AHR CN was more frequent than CN loss in four different pig breeds.An association analysis showed that AHR CN had a positive effect on litter size(P<0.05)and that a higher CN was associated with higher total number born(P<0.05),number born alive(P<0.05),number of weaned piglets,and birth weight.Conclusions:The present study provides comprehensive CNVRs for Meishan and Duroc pigs through large-scale population resequencing.Our results provide a supplement for the high-resolution map of copy number variation in the porcine genome and valuable information for the investigation of genomic structural variation underlying traits of interest in pig.In addition,the association results provide evidence for AHR as a candidate gene associated with reproductive traits that can be used as a genetic marker in pig breeding programs.展开更多
Porcine reproductive traits are characterized by low heritability, making improvement by traditional selective breeding rather difficult. Molecular breeding offers powerful approaches to overcome previous limitations ...Porcine reproductive traits are characterized by low heritability, making improvement by traditional selective breeding rather difficult. Molecular breeding offers powerful approaches to overcome previous limitations and is expected to generate economic benefits via progress in pig breeding. Cytochrome P450 family 19 subfamilyA polypeptide 1 （CYP19A1） gene is a key enzyme of estradiol biosynthesis that plays an important role in the establishment of gestation and maintenance of pregnancy. In this study, the sequence and structure characteristics of the porcine CYP19A1 gene was analyzed and expression patterns of CYP19A 1 in different tissues of adult female pigs were detected. Fourteen single-nucleotide poly- morphisms （SNPs） in the exons and introns of porcine CYP19A1 were identified and genotyped using the Sequenom MassARRAY platform, after which the allele frequency of each SNP was analyzed..The association between CYP19A1 SNPs and litter size and piglet birth weight was assessed in a crossbred pig population （n=375）. The expression pattern of CYPf9A1 revealed that it was highly expressed in the ovary, spleen, and uterus and lowly expressed in the other tissues. Moreover, one SNP, rs341891833, was significantly associated with piglet birth weight during the multiparity period （P〈0.01）. We concluded that CYP19A1 could be used as a candidate molecular marker in breeding aimed at rapid improvement of the reproductive characteristics of pigs.展开更多
We estimated the reproductive success of adult brood fish and the heritability of growthrelated traits for large yellow croaker （Larimichthys crocea）. We created two independent full-factorial cross groups （1 and 2...We estimated the reproductive success of adult brood fish and the heritability of growthrelated traits for large yellow croaker （Larimichthys crocea）. We created two independent full-factorial cross groups （1 and 2） by crossing 4 malesx4 females and 4 males^3 females, respectively. We measured the body weight （BW）, body length （BL）, and body height （BH） of 281 individuals from group 1 and 318 individuals from group 2 at 20 months post hatch （harvest age）. We also collected a tissue sample from each individual. The parents and offspring were genotyped using six polymorphic mierosatellites. Of the 599 offspring, 99.2% were assigned to a single pair of parents. In both groups, some parent pairs produced a large number of offsprings while other pairs did not produce any offspring. The genetic diversity and putative No were lower in the offsprings than in the parents in both groups. The heritability estimates at 20-month age were 0.13±0.10 for BW, 0.19±0.13 for BL, and 0.09±0.06 for BH. The genetic and phenotype correlation between BW, BL, and BH was close to 1. The results provide basic information for selective breeding and further genetic characterization of large yellow croaker.展开更多
Abstract We collected gravid gray rat snakes Ptyas korros from three geographically distinct populations in China, Chenzhou （CZ）, Jiangshan （JS） and Dinghai （DH）, to study geographical variation in female reprod...Abstract We collected gravid gray rat snakes Ptyas korros from three geographically distinct populations in China, Chenzhou （CZ）, Jiangshan （JS） and Dinghai （DH）, to study geographical variation in female reproductive traits. Egg-laying dates differed among the three populations such that at the most northern latitude egg-laying was latest, and earliest at the most southern latitutde. Clutch size, clutch mass, egg mass, egg shape, within clutch variability in egg sizes and relative clutch mass differed among the three populations, whereas post-oviposition body mass did not. Except for egg-laying date, none of the traits examined varied in a geographically continuous trend. CZ and DH females, although separated by a distance of approximately 1100 km as the crow flies, were similar in nearly all traits examined. JS females were distinguished from CZ and DH females by their higher fecundity （clutch size）, greater reproductive output （clutch mass） and more rounded eggs. Our data do not validate the prediction that larger offspring should be produced in colder localities. The absence of an egg size-number trade-off in each of the three populations presumably suggests that P. korros is among species where eggs are well optimized for size within a population.展开更多
Urbanization brings new selection pressures to wildlife living in cities,and changes in the life-history traits of urban species can reflect their responses to such pressures.To date,most of the studies investigating ...Urbanization brings new selection pressures to wildlife living in cities,and changes in the life-history traits of urban species can reflect their responses to such pressures.To date,most of the studies investigating the impacts of urbanization on avian life-history traits are conducted in Europe and North America,while such studies are often lacking in quickly developing countries in Asia(e.g.,China).In this study,we examined the variations in reproductive life-history traits of Chinese Bulbuls(Pycnonotus sinensis)along the urbanization gradient in Hangzhou,China.We detected 234 natural nests of Chinese Bulbuls and continuously monitored them in two continuous breeding seasons from 2012 to 2013.We collected data on seven life-history traits(laying date,incubation period,nestling period,clutch size,egg volume,hatching success rate,and fledging success rate).We used infrared cameras to record the number of feedings per hour as the measure of food resources for the nestlings.We measured nest predation pressure by monitoring 148 natural breeding nests during breeding seasons and 54 artificial nests immediately after breeding seasons.We then calculated the urbanization synthetic index(USI)as a measure of the level of urbanization and examined its relationship with the seven life-history traits.We found that Chinese Bulbuls laid eggs significantly earlier with increasing USI.However,the other six life-history traits did not vary significantly with the USI.Moreover,the feeding frequency of chicks increased significantly with the USI,but the nest predation pressure of Chinese Bulbuls decreased significantly with the USI.Increased food resources and reduced nest predation pressure in cities may lead to earlier laying date of Chinese Bulbuls.Further study should test whether the earlier laying date of Chinese Bulbuls is the result of phenotypic plasticity or genetic change.展开更多
The objective of this study was to estimate the allele and genotype frequencies of the UCP/Hha1 polymorphisms and to determine associations between these polymorphisms and growth traits, breeding value of growth and r...The objective of this study was to estimate the allele and genotype frequencies of the UCP/Hha1 polymorphisms and to determine associations between these polymorphisms and growth traits, breeding value of growth and reproductive traits in Mazandaran Indigenous Chicken. To estimate breeding value of the reproductive traits, and phenotypic information of 18 successive generations of selection in breeding station of Mazandaran Indigenous Chicken (north of Iran), 190 birds were analyzed using a univariate animal model in ASREML procedure.. Genotyping of UCP gene polymorphism for all subjects was performed by the PCR–RFLP method. The evaluation of the association between this SNP with reproductive traits suggests a positive effect of TC genotype with age at first egg (ASM) compared with CC genotype. In addition, TC genotype was significantly associated with breeding value of age at first egg compared with CC genotype (P < 0.05). In conclusion, our results suggest that the TC genotype of the UCP gene is associated with age at sexual maturity (ASM) and breeding value of age at sexual maturity, and UCP polymorphisms may be used as DNA markers for selection in the breeding process of Mazandaran Indigenous Chicken.展开更多
Anti-Mullerian hormone (AMH) is an endocrine marker for fertility in many species. This study investigated possible correlations between serum AMH concentrations, mean number of lambs born (out-of-season in spring or ...Anti-Mullerian hormone (AMH) is an endocrine marker for fertility in many species. This study investigated possible correlations between serum AMH concentrations, mean number of lambs born (out-of-season in spring or fall), and estimated breeding values (EBVs) for number of lambs born (NLB), number of lambs weaned (NLW), maternal weaning weight (MWWT), weaning weight (WWT), and maternal index (determined by Sheep Genetics Australia). Blood was collected at breeding from Katahdin ewes between 0.7 and 7 years of age in 2015 (n = 163) for the analysis of serum concentrations of AMH. Anti-Mullerian hormone concentration was either expressed quantitatively or divided into quartiles (AMH Q1 through Q4, with Q1 the lowest and Q4 the highest, pg/ml). Data were analyzed by PROC CORR, GLM or chi-squared using SAS. Mean serum AMH was 182 ± 11 pg/ml and ranged from 0 to 1112 pg/ml. There was no correlation between serum AMH and EBVs for NLB, NLW, MWWT, WWT and the maternal index. Serum AMH concentration was similar in ewes in different age categories (P = 0.157). There was a correlation between EBV for NLB (0.29;P = 0.0002) and NLW (0.19;P = 0.013) with average number of lambs born. Ewes in the lowest AMH quartile (Q1) had a lower mean number of offspring born from spring breeding compared with ewes in other AMH quartiles (Q2, Q3, and Q4;P < 0.05). Further study is needed to determine the effectiveness of using serum AMH for selecting ewes for out-of-season (spring) breeding.展开更多
This experiment aimed to evaluate the effect of calcium salts of linseed oil (rich in alpha-linolenic acid (ALA, C18:3n-3) on metabolic and reproductive traits in high-producing dairy cows under grazing. Thirty-six Ho...This experiment aimed to evaluate the effect of calcium salts of linseed oil (rich in alpha-linolenic acid (ALA, C18:3n-3) on metabolic and reproductive traits in high-producing dairy cows under grazing. Thirty-six Holstein dairy cows were randomly assigned, in a complete block design, to receive ALA supplementation (0.85 kg∙day−1 of calcium salts of linseed oil) or to remain as untreated control (CON). The concentrate was formulated to offer the same amount of energy across treatments (CON cows received an extra kg of corn to compensate for the higher energy density of ALA treatment). A PMR + Alfalfa pasture was offered to all cows at the same time. A fixed time artificial insemination (FTAI) at 80 DIM, preceded by a Presynch plus Ovsynch protocol was implemented for the first service and later, on return to estrus, heat detection and artificial insemination (AI) were performed. Pregnancy diagnosis was checked at 30, 42, 60, and 90 d after AI. Blood and milk samples were taken biweekly. Treatment affected plasma cholesterol concentration (160.36 vs. 186.70 mg∙dl−1, p = 0.03, for ALA and CON, respectively) and on size of corpus luteum (CL, 17.6 vs. 13.7 mm, p = 0.02, for ALA and CON, respectively). Supplementation tended (p = 0.136) to increase conception rate by 200 DIM (81.69% vs. 55.43% in ALA and CON cows, respectively). However, treatment had no effect (p > 0.05) on body weight (BW), body condition score (BCS), and circulating levels of beta-hydroxybutyrate (BHBA), glucose, insulin, growth hormone (GH) and insulin-like growth factor (IGF-I). Our results suggest that supplementation with calcium salts of linseed oil could enhance ovarian function without affecting energy metabolism in early lactation dairy cows.展开更多
[Objective] This study aimed to estimate the genetic parameters for milk yield, fat percentage, fat yield and age at first freshening of Chinese Holsteins first lactation cows in Heilongjiang under frigid-temperature ...[Objective] This study aimed to estimate the genetic parameters for milk yield, fat percentage, fat yield and age at first freshening of Chinese Holsteins first lactation cows in Heilongjiang under frigid-temperature and temperature zone. [Method] Records of yield and reproduction from 8 868 Chinese Holstein first lacta- tion cows from 21 herds were utilized to evaluate genetic parameters for Hei- Iongjiangs＇ Chinese Holsteins. Restricted maximum likelihood （REML） method was used with an animal model. [Result] The heritabilities were 0.16 to 0.34 for yields and fat percentage, 0.38 for reproduction （age at the first freshening）, which were similar to estimates for temperate areas from similar methods, except for constituent percentage. Also, the estimates of genetic correlation were high between milk yield and fat yield （0.97）, but were low between milk yield and fat percentage （-0.24）, age at the first freshening （-0.29） and generally antagonistic. [Conclusion] Thus, es- timates of genetic parameters in this frigid and frigid-temperate environment did not differ appreciably from those that occur in temperate dairy areas.展开更多
To understand the reproductive biology of Hemitripterus villosus in the Bohai Strait,and fill the key knowledge gap in verifying reproductive seasonality and documenting gonadotropin dependent reproductive cycle of th...To understand the reproductive biology of Hemitripterus villosus in the Bohai Strait,and fill the key knowledge gap in verifying reproductive seasonality and documenting gonadotropin dependent reproductive cycle of this species,a year-round detail study was conducted for the first time.In total,263 individuals were randomly sampled off the coasts of the Bohai Strait.Results show that and the overall female-to-male ratio(1.35:1)did not differ significantly from the 1:1 sex ratio.The length and weight relationship for females and males were regressed,depicting an isometric growth for both sexes.Four reproductive phases of the complete gonadotropin dependent reproductive cycle in both sexes were identified.The monthly variations in the gonadosomatic and hepatosomatic indexes for both sexes further indicated that this species spawns a single batch of eggs per year and the peak spawning period is from October to December.The average diameter of eggs ranged from 2.10 to 3.57 mm.The length at first sexual maturity was 224.87 mm for females and 241.26 mm for males.Significant positive relationships between absolute fecundity and fish size,and also gonadal weight were observed.H.villosus from the Bohai Strait exhibited smaller body size,smaller egg diameter,lower gonadosomatic index,lower absolute fecundity,and higher population extinction risk than the other populations’studied previously.Our findings contribute to understanding the status of this isolated westernmost population,and we emphasize that more efficient protection measures for the species and control measures are urgently required to improve the coastal environment in the Bohai Strait.展开更多
基金supported and funded by the National Key Research and Development Program of China(2023YFD1300801)the Agricultural Science and Technology Innovation Program in Chinese Academy of Agricultural Sciences(ASTIP-IAS-08)。
文摘Background The decline in reproductive performance of aged hens is mainly attributed to oxidative damage in reproductive organs,hepatic lipid metabolism disorders,and intestinal microbiota dysbiosis.Glycyrrhizin(GL)has been proven to enhance antioxidant capacity,regulate lipid metabolism and gut microbiota in mammals,but its efficacy in hens remains unclear.Hence,this study aimed to investigate whether dietary GL supplementation improves reproductive performance in hens during the late laying stage by modulating intestinal microbiota composition,hepatic lipid metabolism and ovarian antioxidant status.Results Dietary supplementation with 100 mg/kg GL significantly improved the egg production rate,egg quality,and hatching rate in aged breeder hens(P<0.05).GL supplementation also increased the serum levels of HDLC,TP and ALB,and enhanced the antioxidant capacity in both serum and ovary(P<0.05).In addition,dietary GL elevated the serum progesterone(P4)levels by enhancing the transcription level of steroid synthesis key enzymes(CYP11A1 and 3β-HSD)in the ovary(P<0.05).Dietary GL also promoted the synthesis and transport of vitellogenin(VTG)by upregulating the VTG-Ⅱ(P<0.05)and APOV1(P=0.077)expression levels in the liver,thereby increasing the number of grade follicles and small yellow follicles.Moreover,dietary GL enhanced hepatic fatty acidβ-oxidation by upregulating PPARαand CPT-I(P<0.05),and downregulating ACC expression levels(P<0.05).In agreement,liver metabolomics analysis revealed that dietary GL supplementation significantly altered hepatic metabolism,with 389 differentially identified metabolites(P<0.05).The key metabolites(e.g.,taurocholic acid,tauroursodeoxycholic acid,nicotinuric acid,glycodeoxycholic acid(hydrate))were identified,and they were mainly functionally enriched in betaalanine metabolism nicotinate,taurine and hypotaurine metabolism(P<0.05).Finally,16S rRNA gene sequencing revealed that dietary GL reversed age-induced changes in gut microbiota composition,characterized by a significant increase in Lactobacillus abundance and a decrease in Bacteroides(P<0.05).Conclusions These results collectively demonstrate that dietary supplementation with 100 mg/kg GL improved reproductive performance by reversing age-induced changes in gut microbiota,enhancing hepatic vitellogenin synthesis,and ameliorating ovarian function in aged breeder hens.This study suggests that dietary GL is a potential strategy to improve reproductive performance in broiler breeder hens during the late laying period.
基金supported by the National Natural Science Foundation(32130068,32271634,and 32071597)CAS Key Laboratory of Forest Ecology and Silviculture,Institute of Applied Ecology,Chinese Academy of Sciences(KLFES-2025)。
文摘Urban forests are highly multifunctional and provide numerous ecological functions.Plant functional traits individually or jointly influence the ecological multifunctionality of tree species(TS-EMF)and can also modify TSEMF in response to environmental changes.However,there has been limited exploration of multitrait combinations for predicting TS-EMF across seasons and of trait thresholds that enhance TS-EMF.Here,for 10 dominant tree species in urban forests of Northeast China,14 traits were measured and four aboveground and three belowground ecological functions assessed in three seasons.Ecological functions and TS-EMF differed significantly throughout the seasons(P<0.05).Synergistic relationships were found between carbon sequestration and oxygen release,between cooling and humidification,and between organic carbon accumulation and nutrient cycling.Notably,aboveground multifunctionality played a leading role in TS-EMF.With seasonal changes,resource allocation shifted toward traits related to resource acquisition rather than conservation to maintain TS-EMF.The combination of traits that predicted TS-EMF varied by type,accounting for up to 66.45%of the variation.TS-EMF was primarily driven by leaf structure in spring and by nutrient accumulation in autumn.Leaf carbon content(LCC)consistently served as a stabilizing factor for predicting TS-EMF across seasons.At 36.5-36.8 mg g^(-1),LCC had its optimal effect on TS-EMF.Other traits in combination that positively influence total TS-EMF include leaf nitrogen content(3.43-3.45 mg g^(-1)),leaf phosphorus content(0.80-0.83 mg g^(-1)),and leaf area(65.86-68.43 cm^(2)).Within these specified trait thresholds,Morus alba and Quercus mongolica were identified as key species.These findings suggest that the trade-off between various ecological functions can be managed by altering plant traits across seasons.This approach could provide a theoretical foundation for enhancing the TS-EMF of urban forests through trait-based management,offering practical guidance for selecting tree species.
文摘Background:Epidemiological studies have confirmed that longer exposure to insecticides like cypermethrin(CYP)significantly increases the risk of male reproductive toxicity.Crocus sativus L.has been recognized due to its therapeutic properties,but its exact role and molecular mechanisms in treatment of reproductive dysfunction remain unclear.Methods:During this study,36 rats were randomly divided into six groups(n=6):control,CYP-induced(60 mg/kg),standard(leuprolide 3 mg/kg)and three treatment groups receiving aqueous,ethanolic,and oil extracts(50 mg/kg or 20 mL/kg)for post-toxicity induction.Results:The finding represented that exposure of CYP significantly increased oxidative stress,disrupted testicular architecture,and markedly reduced testosterone levels(P<0.05).Importantly,Crocus sativus L.treatment alleviated these changes by increasing the expression of Nrf2(nuclear factor erythroid 2-related factor 2),restoring the activity of antioxidant enzymes,and enhancing testicular histomorphology.Surprisingly,molecular docking established a high binding affinity of Crocus sativus L.phytoconstituents such as gallic acid,cinnamic acid and quercetin to the Nrf2-Keap1 complex.It is worth noting that,Crocus sativus L.exhibited a high level of protection against reproductive toxicity caused by CYP in male rats,which was mediated by the activation of Nrf2 pathway,reduction of oxidative damage,and favorable ADMET characteristics.Conclusion:Notably,this research provides a more valid,safe,and effective method of developing new drugs for reproductive disorders,however,further investigation is needed to support the research findings and implement it in clinical practice.
基金supported by Yunnan Key Laboratory of Animal Reproductive Biology(2010-03)
文摘The objective of this study was to set up a rhesus monkey model of polycystic ovary syndrome（PCOS）,which is globally prevalent among reproductive-aged human women,and to understand the reproductive traits of PCOS female monkeys.Six adult female rhesus monkeys aged 6-10 a,were divided into a PCOS group and a control group.The PCOS group were given two cycles of subcutaneous injections of propionic acid testosterone（PAT）,3.5 mg/kg body weight,on day 1,day 3,and day 5 of the menstrual cycle,respectively,and then given muscle injections of human chorionic gonadotropin（HCG）,350 IU/kg body wtight,on day 7,day 9,and day 11,respectively.Results showed that high levels of serum LH and T [（5.35±0.17） IU/L and（7.58±0.14） ng/mL,respectively],and a high ratio value of LH/FSH（5.35/1.30=4.12） were observed in the PCOS group.No significant differences were found in serum FSH,E2,and P in the PCOS group compared with those of the control.Polycystic ovaries in the PCOS monkeys were recorded by live ultrasound.The blastocysts rates of the PCOS vs.the control were 23.53% vs.66.67%,and there was a significant difference between the two groups.This study shows that PAT coupled with HCG can induce PCOS in rhesus monkeys in the short term.The reproductive features of PCOS monkeys were similar to those of PCOS patients.
基金supported by the open-fund of Key Laboratory of Fisheries Genetic Resources and Aquaculture,Chinese Academy of Fisheries Sciences of China (2008B1207)New Teacher Special Fund of Doctor of Ministry of Education of China (20090132120006)
文摘Follicle stimulating hormone β (FSHβ) of Japanese flounder (Paralichthys olivaceus) plays a key role in the regulation of gonadal development.This study aimed to investigate molecular genetic characteristics of the FSHβ gene and elucidate the effects of single nucleotide polymorphisms (SNPs) of FSHβ on reproductive traits in Japanese flounder.We used polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP) and sequencing of the FSHβ gene in 60 individuals.We identified only an SNP (T/C) in the coding region of exon3 of FSHβ.The SNP (T/C) did not lead to amino acid changes at the position 340 bp of FSHβ gene.Statistical analysis showed that the SNP was significantly associated with testosterone (T) level and gonadosomatic index (GSI) (P<0.05).Individuals with genotype TC of the SNP had significantly higher serum T levels and GSI (P<0.05) than that of genotype CC.Therefore, FSHβ gene could be a useful molecular marker in selection for prominent reproductive trait in Japanese Flounder.
基金supported by the Special Scientific Research Program for Non-profit Professions (200709017)
文摘Conyza sumatrensis （Retz.） E. Walker, a member of Asteraceae, is a highly invasive species. However, its reproduction biology remains poorly known. To understand the role of reproductive traits in successful invasion of the species, we studied several traits of its reproductive system： the miniature capitulum and gynomonoecious sexual system, the biology and phenology of capitula and florets, pollen/ovule ratio, the mating system （selfcompatibility）, flower visitors, physical traits and dispersal potential of achenes, germination potential of achenes from manually pollinated capitula, and the association of these traits with invasiveness. Our study showed that the reproductive traits of autonomous seed production, versatile mating system of self- and cross-pollination, and generalized pollination system might contribute to the species＇ successful invasive capability. The invasiveness was further enhanced by the high and rapid production of achenes, as well as the high percentage, rapid germination rate and high dispersal capability of achenes. It was concluded that in annual or winter-annual weeds, autonomous seed production contributed significantly to the invasiveness of the species.
基金supported by Project 2016-X39 of the Introduction of International Advanced Agricultural Science and Technology PlanProject 2015ASKJ02 of the Scientific and Technological Innovation Project Financially Supported by Qingdao National Laboratory for Marine Science and Technology+4 种基金Project BE2014414 of the Jiangsu Province Science and Technology Support ProgramProject of the Guangdong Province Agricultural Improved Variety Establishment of System ProjectProject of Taishan scholar program for seed industryProject 14-2-4-52-jch5 of the Qingdao Scientific Research FoundationProject 2016GGF01064 of Key research and development project of Shandong Province
文摘In this study, the heritability, repeatability, phenotypic correlation, and genetic correlation of the reproductive and growth traits of L. vannamei were investigated and estimated. Eight traits of 385 shrimps from forty-two families, including the number of eggs(EN), number of nauplii(NN), egg diameter(ED), spawning frequency(SF), spawning success(SS), female body weight(BW) and body length(BL) at insemination, and condition factor(K), were measured,. A total of 519 spawning records including multiple spawning and 91 no spawning records were collected. The genetic parameters were estimated using an animal model, a multinomial logit model(for SF), and a sire-dam and probit model(for SS). Because there were repeated records, permanent environmental effects were included in the models. The heritability estimates for BW, BL, EN, NN, ED, SF, SS, and K were 0.49 ± 0.14, 0.51 ± 0.14, 0.12 ± 0.08, 0, 0.01 ± 0.04, 0.06 ± 0.06, 0.18 ± 0.07, and 0.10 ± 0.06, respectively. The genetic correlation was 0.99 ± 0.01 between BW and BL, 0.90 ± 0.19 between BW and EN, 0.22 ± 0.97 between BW and ED,-0.77 ± 1.14 between EN and ED, and-0.27 ± 0.36 between BW and K. The heritability of EN estimated without a covariate was 0.12 ± 0.08, and the genetic correlation was 0.90 ± 0.19 between BW and EN, indicating that improving BW may be used in selection programs to genetically improve the reproductive output of L. vannamei during the breeding. For EN, the data were also analyzed using body weight as a covariate(EN-2). The heritability of EN-2 was 0.03 ± 0.05, indicating that it is difficult to improve the reproductive output by genetic improvement. Furthermore, excessive pursuit of this selection is often at the expense of growth speed. Therefore, the selection of high-performance spawners using BW and SS may be an important strategy to improve nauplii production.
基金Funding for this study was provided by National Basic Research Program of China(973 Program,Grant 2014CB138501)the National Transgenic Animal Breeding Grand Project(2014ZX08006–005)the Program for Changjiang Scholars and Innovation Research Teams in the University(IRT_15R62)
文摘Background： Follicle-stimulating hormone（FSH） is a gonadotropin synthesized and secreted by the pituitary gland.FSH stimulates follicle development and maturation in females. It also plays an important role in spermatogenesis in males, including humans and mice. However, the effects of FSH on male pigs are largely unknown. In this study,we generated transgenic pigs to investigate the effects of FSHα/β overexpression on reproductive traits in boars.Results： After five transgenic F0 founders were crossed with wide-type pigs, 193 F_1 animals were obtained. Of these,96 were confirmed as transgenic. FSHα and FSHβ m RNAs were detected only in pituitary tissue. Transgenic boars exhibited significantly higher levels of FSHα and FSHβ m RNA, serum FSH, and serum testosterone, compared to ful-sib non-transgenic boars. Significant increases in testis weight, vas deferens diameter, seminiferous tubule diameter,and the number of Leydig cel s were observed, suggesting that the exogenous FSHα/β affects reproductive traits. Final y,transgenic and non-transgenic boars had similar growth performance and biochemical profiles.Conclusions： Pituitary-specific overexpression of FSHα/β genes is likely to impact reproductive traits positively, as indicated by enhancements in serum testosterone level, testis weight, the development of vas deferens, seminiferous tubules, and Leydig cells in transgenic boars. A high level of serum FSH induces secretion of serum testosterone,possibly by boosting the number of Leydig cells, which presumably increases the libido and the frequency of sexual activity in transgenic boars. Our study provides a preliminary foundation for the genetic improvement of reproductive traits in male pigs.
基金Project(31300343)supported by the National Natural Science Foundation of ChinaProject supported by Jiangsu Collaborative Innovation Center of Technology and Material of Water Treatment,ChinaProject(12JDG086)supported by Research Foundation for Advanced Talents of Jiangsu University,China
文摘Because co-occurring native and invasive plants are subjected to similar environmental selection pressures,the differences in functional traits and reproductive allocation strategies between native and invasive plants may be closely related to the success of the latter.Accordingly,this study examines differences in functional traits and reproductive allocation strategies between native and invasive plants in Eastern China.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants were all notably higher than those of native species.Additionally,the specific leaf area(SLA)values of invasive plants were remarkably lower than those of native species.Plasticity indexes of SLA,maximum branch angle,and branch number of invasive plants were each notably lower than those of native species.The reproductive allocation coefficient was positively correlated with reproductive branch number and the belowground-to-aboveground biomass ratio but exhibited negative correlations with SLA and aboveground biomass.Plant height,branch number,reproductive branch number,the belowground-to-aboveground biomass ratio,and the reproductive allocation coefficient of invasive plants may strongly influence the success of their invasions.
基金This work was financially supported by National Natural Science Foundations of China(31661143013)National Natural Science Foundation of China(No.31790414)+1 种基金National Key R&D Program of China(2018YFD0501200)and Jinxinnong Animal Science Development Foundation.
文摘Background:Reproductive performance of livestock is an economically important aspect of global food production.The Chinese Meishan pig is a prolific breed,with an average of three to five more piglets per litter than European breeds;however,the genetic basis for this difference is not well understood.Results:In this study,we investigated copy number variations(CNVs)of 32 Meishan pigs and 29 Duroc pigs by nextgeneration sequencing.A genome-wide analysis of 61 pigs revealed 12,668 copy number variable regions(CNVRs)that were further divided into three categories based on copy number(CN)of the whole population,i.e.,gain(n=7,638),and loss(n=5,030)CNVRs.We then compared Meishan and Duroc pigs and identified 17.17Mb of 6,387 CNVRs that only existing in Meishan pigs CNVRs that overlapped the reproduction-related gene encoding the aryl hydrocarbon receptor(AHR)gene.We found that normal AHR CN was more frequent than CN loss in four different pig breeds.An association analysis showed that AHR CN had a positive effect on litter size(P<0.05)and that a higher CN was associated with higher total number born(P<0.05),number born alive(P<0.05),number of weaned piglets,and birth weight.Conclusions:The present study provides comprehensive CNVRs for Meishan and Duroc pigs through large-scale population resequencing.Our results provide a supplement for the high-resolution map of copy number variation in the porcine genome and valuable information for the investigation of genomic structural variation underlying traits of interest in pig.In addition,the association results provide evidence for AHR as a candidate gene associated with reproductive traits that can be used as a genetic marker in pig breeding programs.
基金supported by the National Natural Science Foundation of China(31501931)the 948 Program of China(2011-G11)the Agricultural Science and Technology Innovation Program,China(ASTIP-IAS05)
文摘Porcine reproductive traits are characterized by low heritability, making improvement by traditional selective breeding rather difficult. Molecular breeding offers powerful approaches to overcome previous limitations and is expected to generate economic benefits via progress in pig breeding. Cytochrome P450 family 19 subfamilyA polypeptide 1 （CYP19A1） gene is a key enzyme of estradiol biosynthesis that plays an important role in the establishment of gestation and maintenance of pregnancy. In this study, the sequence and structure characteristics of the porcine CYP19A1 gene was analyzed and expression patterns of CYP19A 1 in different tissues of adult female pigs were detected. Fourteen single-nucleotide poly- morphisms （SNPs） in the exons and introns of porcine CYP19A1 were identified and genotyped using the Sequenom MassARRAY platform, after which the allele frequency of each SNP was analyzed..The association between CYP19A1 SNPs and litter size and piglet birth weight was assessed in a crossbred pig population （n=375）. The expression pattern of CYPf9A1 revealed that it was highly expressed in the ovary, spleen, and uterus and lowly expressed in the other tissues. Moreover, one SNP, rs341891833, was significantly associated with piglet birth weight during the multiparity period （P〈0.01）. We concluded that CYP19A1 could be used as a candidate molecular marker in breeding aimed at rapid improvement of the reproductive characteristics of pigs.
基金Supported by the Special Fund for Agro-Scientific Research in the Public Interest (No. 200903029-4)Key Project of Science and Technology Department of Fujian Province (No. 2010N0021)the Foundation for Young Professors of Jimei University (No. 2009C002)
文摘We estimated the reproductive success of adult brood fish and the heritability of growthrelated traits for large yellow croaker （Larimichthys crocea）. We created two independent full-factorial cross groups （1 and 2） by crossing 4 malesx4 females and 4 males^3 females, respectively. We measured the body weight （BW）, body length （BL）, and body height （BH） of 281 individuals from group 1 and 318 individuals from group 2 at 20 months post hatch （harvest age）. We also collected a tissue sample from each individual. The parents and offspring were genotyped using six polymorphic mierosatellites. Of the 599 offspring, 99.2% were assigned to a single pair of parents. In both groups, some parent pairs produced a large number of offsprings while other pairs did not produce any offspring. The genetic diversity and putative No were lower in the offsprings than in the parents in both groups. The heritability estimates at 20-month age were 0.13±0.10 for BW, 0.19±0.13 for BL, and 0.09±0.06 for BH. The genetic and phenotype correlation between BW, BL, and BH was close to 1. The results provide basic information for selective breeding and further genetic characterization of large yellow croaker.
基金The work was carried out in compliance with the current laws on animal welfare and research in China, and was supported by grants from Natural Science Foundation of China （30770378 and 31071910）, Zhejiang Provincial Foundation of Natural Science （Z3090461）, Hangzhou Bureau of Science and Technology （20100332T20） and Zhejiang Department of Science and Technology for Innovation Teams （2010R50039-26）. We thank Jian-Fang Gao, Rui-Bin Hu, Yan-Fu Qu and Ling Zhang for their help during the research.
文摘Abstract We collected gravid gray rat snakes Ptyas korros from three geographically distinct populations in China, Chenzhou （CZ）, Jiangshan （JS） and Dinghai （DH）, to study geographical variation in female reproductive traits. Egg-laying dates differed among the three populations such that at the most northern latitude egg-laying was latest, and earliest at the most southern latitutde. Clutch size, clutch mass, egg mass, egg shape, within clutch variability in egg sizes and relative clutch mass differed among the three populations, whereas post-oviposition body mass did not. Except for egg-laying date, none of the traits examined varied in a geographically continuous trend. CZ and DH females, although separated by a distance of approximately 1100 km as the crow flies, were similar in nearly all traits examined. JS females were distinguished from CZ and DH females by their higher fecundity （clutch size）, greater reproductive output （clutch mass） and more rounded eggs. Our data do not validate the prediction that larger offspring should be produced in colder localities. The absence of an egg size-number trade-off in each of the three populations presumably suggests that P. korros is among species where eggs are well optimized for size within a population.
基金supported by the National Natural Science Foundation of China(32271743,31971545,31071908)。
文摘Urbanization brings new selection pressures to wildlife living in cities,and changes in the life-history traits of urban species can reflect their responses to such pressures.To date,most of the studies investigating the impacts of urbanization on avian life-history traits are conducted in Europe and North America,while such studies are often lacking in quickly developing countries in Asia(e.g.,China).In this study,we examined the variations in reproductive life-history traits of Chinese Bulbuls(Pycnonotus sinensis)along the urbanization gradient in Hangzhou,China.We detected 234 natural nests of Chinese Bulbuls and continuously monitored them in two continuous breeding seasons from 2012 to 2013.We collected data on seven life-history traits(laying date,incubation period,nestling period,clutch size,egg volume,hatching success rate,and fledging success rate).We used infrared cameras to record the number of feedings per hour as the measure of food resources for the nestlings.We measured nest predation pressure by monitoring 148 natural breeding nests during breeding seasons and 54 artificial nests immediately after breeding seasons.We then calculated the urbanization synthetic index(USI)as a measure of the level of urbanization and examined its relationship with the seven life-history traits.We found that Chinese Bulbuls laid eggs significantly earlier with increasing USI.However,the other six life-history traits did not vary significantly with the USI.Moreover,the feeding frequency of chicks increased significantly with the USI,but the nest predation pressure of Chinese Bulbuls decreased significantly with the USI.Increased food resources and reduced nest predation pressure in cities may lead to earlier laying date of Chinese Bulbuls.Further study should test whether the earlier laying date of Chinese Bulbuls is the result of phenotypic plasticity or genetic change.
文摘The objective of this study was to estimate the allele and genotype frequencies of the UCP/Hha1 polymorphisms and to determine associations between these polymorphisms and growth traits, breeding value of growth and reproductive traits in Mazandaran Indigenous Chicken. To estimate breeding value of the reproductive traits, and phenotypic information of 18 successive generations of selection in breeding station of Mazandaran Indigenous Chicken (north of Iran), 190 birds were analyzed using a univariate animal model in ASREML procedure.. Genotyping of UCP gene polymorphism for all subjects was performed by the PCR–RFLP method. The evaluation of the association between this SNP with reproductive traits suggests a positive effect of TC genotype with age at first egg (ASM) compared with CC genotype. In addition, TC genotype was significantly associated with breeding value of age at first egg compared with CC genotype (P < 0.05). In conclusion, our results suggest that the TC genotype of the UCP gene is associated with age at sexual maturity (ASM) and breeding value of age at sexual maturity, and UCP polymorphisms may be used as DNA markers for selection in the breeding process of Mazandaran Indigenous Chicken.
文摘Anti-Mullerian hormone (AMH) is an endocrine marker for fertility in many species. This study investigated possible correlations between serum AMH concentrations, mean number of lambs born (out-of-season in spring or fall), and estimated breeding values (EBVs) for number of lambs born (NLB), number of lambs weaned (NLW), maternal weaning weight (MWWT), weaning weight (WWT), and maternal index (determined by Sheep Genetics Australia). Blood was collected at breeding from Katahdin ewes between 0.7 and 7 years of age in 2015 (n = 163) for the analysis of serum concentrations of AMH. Anti-Mullerian hormone concentration was either expressed quantitatively or divided into quartiles (AMH Q1 through Q4, with Q1 the lowest and Q4 the highest, pg/ml). Data were analyzed by PROC CORR, GLM or chi-squared using SAS. Mean serum AMH was 182 ± 11 pg/ml and ranged from 0 to 1112 pg/ml. There was no correlation between serum AMH and EBVs for NLB, NLW, MWWT, WWT and the maternal index. Serum AMH concentration was similar in ewes in different age categories (P = 0.157). There was a correlation between EBV for NLB (0.29;P = 0.0002) and NLW (0.19;P = 0.013) with average number of lambs born. Ewes in the lowest AMH quartile (Q1) had a lower mean number of offspring born from spring breeding compared with ewes in other AMH quartiles (Q2, Q3, and Q4;P < 0.05). Further study is needed to determine the effectiveness of using serum AMH for selecting ewes for out-of-season (spring) breeding.
文摘This experiment aimed to evaluate the effect of calcium salts of linseed oil (rich in alpha-linolenic acid (ALA, C18:3n-3) on metabolic and reproductive traits in high-producing dairy cows under grazing. Thirty-six Holstein dairy cows were randomly assigned, in a complete block design, to receive ALA supplementation (0.85 kg∙day−1 of calcium salts of linseed oil) or to remain as untreated control (CON). The concentrate was formulated to offer the same amount of energy across treatments (CON cows received an extra kg of corn to compensate for the higher energy density of ALA treatment). A PMR + Alfalfa pasture was offered to all cows at the same time. A fixed time artificial insemination (FTAI) at 80 DIM, preceded by a Presynch plus Ovsynch protocol was implemented for the first service and later, on return to estrus, heat detection and artificial insemination (AI) were performed. Pregnancy diagnosis was checked at 30, 42, 60, and 90 d after AI. Blood and milk samples were taken biweekly. Treatment affected plasma cholesterol concentration (160.36 vs. 186.70 mg∙dl−1, p = 0.03, for ALA and CON, respectively) and on size of corpus luteum (CL, 17.6 vs. 13.7 mm, p = 0.02, for ALA and CON, respectively). Supplementation tended (p = 0.136) to increase conception rate by 200 DIM (81.69% vs. 55.43% in ALA and CON cows, respectively). However, treatment had no effect (p > 0.05) on body weight (BW), body condition score (BCS), and circulating levels of beta-hydroxybutyrate (BHBA), glucose, insulin, growth hormone (GH) and insulin-like growth factor (IGF-I). Our results suggest that supplementation with calcium salts of linseed oil could enhance ovarian function without affecting energy metabolism in early lactation dairy cows.
文摘[Objective] This study aimed to estimate the genetic parameters for milk yield, fat percentage, fat yield and age at first freshening of Chinese Holsteins first lactation cows in Heilongjiang under frigid-temperature and temperature zone. [Method] Records of yield and reproduction from 8 868 Chinese Holstein first lacta- tion cows from 21 herds were utilized to evaluate genetic parameters for Hei- Iongjiangs＇ Chinese Holsteins. Restricted maximum likelihood （REML） method was used with an animal model. [Result] The heritabilities were 0.16 to 0.34 for yields and fat percentage, 0.38 for reproduction （age at the first freshening）, which were similar to estimates for temperate areas from similar methods, except for constituent percentage. Also, the estimates of genetic correlation were high between milk yield and fat yield （0.97）, but were low between milk yield and fat percentage （-0.24）, age at the first freshening （-0.29） and generally antagonistic. [Conclusion] Thus, es- timates of genetic parameters in this frigid and frigid-temperate environment did not differ appreciably from those that occur in temperate dairy areas.
基金Supported by the Technology Innovation Development Program of Yantai(No.2020MSGY055)。
文摘To understand the reproductive biology of Hemitripterus villosus in the Bohai Strait,and fill the key knowledge gap in verifying reproductive seasonality and documenting gonadotropin dependent reproductive cycle of this species,a year-round detail study was conducted for the first time.In total,263 individuals were randomly sampled off the coasts of the Bohai Strait.Results show that and the overall female-to-male ratio(1.35:1)did not differ significantly from the 1:1 sex ratio.The length and weight relationship for females and males were regressed,depicting an isometric growth for both sexes.Four reproductive phases of the complete gonadotropin dependent reproductive cycle in both sexes were identified.The monthly variations in the gonadosomatic and hepatosomatic indexes for both sexes further indicated that this species spawns a single batch of eggs per year and the peak spawning period is from October to December.The average diameter of eggs ranged from 2.10 to 3.57 mm.The length at first sexual maturity was 224.87 mm for females and 241.26 mm for males.Significant positive relationships between absolute fecundity and fish size,and also gonadal weight were observed.H.villosus from the Bohai Strait exhibited smaller body size,smaller egg diameter,lower gonadosomatic index,lower absolute fecundity,and higher population extinction risk than the other populations’studied previously.Our findings contribute to understanding the status of this isolated westernmost population,and we emphasize that more efficient protection measures for the species and control measures are urgently required to improve the coastal environment in the Bohai Strait.
