The nutritional status of an individual can significantly influence its life history traits,including development,growth,reproduction,and survival.In the predatory mite Phytoseiulus persimilis Athias-Henriot(Acari:Phy...The nutritional status of an individual can significantly influence its life history traits,including development,growth,reproduction,and survival.In the predatory mite Phytoseiulus persimilis Athias-Henriot(Acari:Phytoseidae),the plasticity of life history traits,such as developmental time and size at maturity,is influenced by the quality and quantity of food.This study aimed to investigate the effects of dietary restriction at different life stages(i.e.,juvenile,early adulthood,and later adulthood)on the lifespan and fecundity of P persimilis.We found that reduced dietary intake during early adulthood resulted in a shorter lifespan for both male and female P persimilis.Furthermore,this study demonstrated a sex-specific response to dietary restriction:it extended the lifespan of males but reduced that of females during later adulthood.Diet restriction during the postovipositional period of females showed the most variable life history trait response.Our results showed that the impact of diet restriction at different life stages can have combined influences on the postovipositional duration of P persimilis,where the individuals receiving diet restriction during immature development and early adulthood had a greater reduction in ovipositional duration as those experiencing diet restriction during late adulthood.In addition,we observed a positive correlation between the lifespan and fecundity of females,with higher prey availability increasing both.The insights obtained from our research contribute to a better understanding of the aging process and dietary requirements of P persimilis,which can facilitate the development of more effective biological control strategies using this predator for spider mites in agriculture.展开更多
[Objective] The aim was to study on the effect of hosts on development and reproduction of mealybug （Phenacoccus solenopsis Tinsley）. [Method] Observation was conducted on developmental durations and fecundity of Ph...[Objective] The aim was to study on the effect of hosts on development and reproduction of mealybug （Phenacoccus solenopsis Tinsley）. [Method] Observation was conducted on developmental durations and fecundity of Phenacoccus solenopsis Tinsley fed on Gossypium spp., Nicotiana tabacum, Solanum tuberosum L and Hibiscus rosa-sinensis. [Result] There were differences among all durations, generation durations and fecundities of the mealybug adult females. Specifically, the generation durations on cotton （Gossypium spp.）, tobacco（ Nicotiana tabacum）, potato （Solanum tuberosum L） and Hibiscus rosa-sinensis were 30.2, 28.2, 37.3, and 27.7 d, and the fecundities per female were 626.0, 417.2, 552.5, and 183.2 ind., respectively. [Conclusion] The mealybug would have strong pontential in population growth when fed on cotton, tobacco and potato.展开更多
Several recent studies have shown that the fecundity of a man decreases progressively with sperm concentrations below 40 million spermatozoa per mL. Therefore, it is unfortunate that the new World Health Organization ...Several recent studies have shown that the fecundity of a man decreases progressively with sperm concentrations below 40 million spermatozoa per mL. Therefore, it is unfortunate that the new World Health Organization guidelines for semen analysis recommend lowering the lower cutoff value for normal sperm concentration from 20 to 15 million spermatozoa per mL. As a result large groups of subfertile men across the world may not receive appropriate andrological help in the future.展开更多
Although amphioxus is widespread in temperate and tropical seas,its population is diminishing be-cause of environmental pollution.To keep the population of this evolutionarily important animal fromdiminishing,study on...Although amphioxus is widespread in temperate and tropical seas,its population is diminishing be-cause of environmental pollution.To keep the population of this evolutionarily important animal fromdiminishing,study on its reproduction and development is necessary.The main findings in this study onthe spawning and fecundity of the amphioxus reared in laboratory and its larval development are as fol-lows.1.Water temperature markedly affected the spawning.It spawned only when water temperature reached 21℃.2.Spawning of the amphioxus in laboratory was markedly extended.Initially,the amphioxus spawned at about 7:00 PM,but spawning time was postponed as spawning days went on.3.The number of eggs produced by a female ranged from 1400 to 12800,average of 5800.This al-so represents the fecundity of the amphioxus because it shedded all eggs within the ovary at a time.4.During the first few months of life of the amphioxus,its growth rate changed seasonally.Thegrowth rate in summer and fall was greater than that展开更多
We used the Chinese skink Eumeces chinensis as a model animal to study the effects of tail loss on reproductive in- vestment and offspring traits. A total of 147 wild-captured adult females were divided into four grou...We used the Chinese skink Eumeces chinensis as a model animal to study the effects of tail loss on reproductive in- vestment and offspring traits. A total of 147 wild-captured adult females were divided into four groups according to their tail con- ditions. Tail breaks occurred most frequently in the proximal portion of the tail and least frequently in the distal portion, with the middle portion in between. This finding suggests that tail breaks occurring in nature often entails substantial energetic costs in E. chinensis where the tail is a major site of energy storage. The proportion of females that laid eggs was higher in females with in- tact or completely regenerated tails than in those with broken tails. Following whole-tail autotomy, the clutch size was reduced by 17%, and the clutch mass was reduced by 14%. Females undergoing substantial tail autotomy reduced reproductive investment, and they did so by reducing the number but not the size of eggs produced. None of the egg and hatchling traits was affected by tail loss. Comparing our data with those reported for other oviparous and viviparous skinks allows us to draw two general conclu- sions： one is that fecundity （clutch or litter size） is affected by tail loss in all species so far studied, whereas offspring size is af- fected by tail loss in some species, but not in others; the other is that the reduction in fecundity following tail loss is more evident in species lacking abdominal fat bodies展开更多
MicroRNAs(miRNAs)can participate in plant-insect interactions,which regulate plant defense networks.In this study,we analyzed the miRNA expression profiles of six rice varieties before and after brown planthopper(BPH)...MicroRNAs(miRNAs)can participate in plant-insect interactions,which regulate plant defense networks.In this study,we analyzed the miRNA expression profiles of six rice varieties before and after brown planthopper(BPH)-feeding.We identified 45 differentially expressed miRNAs between BPH-susceptible and BPH-resistant rice varieties and 144 miRNAs that responded to BPH-feeding.Thus,miRNAs may be involved in multiple pathways regulating rice defense response against BPH.In addition,we found that the genetic history of rice varieties determined the regulation mode of the miRNA and affected the amounts,types,changing trends and response periods of miRNAs in response to BPH-feeding.To conclude,we scanned seven potential cross-kingdom miRNAs,of which miR5795 may target the vitellogenin gene in BPH,causing a 16.07%reduction in BPH oviposition.The results provide new miRNA information of rice-BPH interactions and BPH-resistant rice variety breeding.展开更多
Social conditions experienced prior to sexual maturity influence reproduction later in life in many animals. In simulta- neous hermaphrodites, variation in mating group size influences reproductive investment. As the ...Social conditions experienced prior to sexual maturity influence reproduction later in life in many animals. In simulta- neous hermaphrodites, variation in mating group size influences reproductive investment. As the mating group size increases, re- productive resources devoted to the female function decrease in favor of the male function. Prior to sexual maturity, many her- maphrodites have a protandrous phase during which they produce sperm and can fertilize hermaphrodites＇ eggs. In the simulta- neously hermaphroditic polychaete worm Ophryotrocha diadema, the cost of male reproduction during adolescence is spread over the whole energy budget of worms as shown by a reduced growth rate, a delayed age at sexual maturity and the shortening of life span compared to protandrous males that do not reproduce. Little is known on whether social conditions experienced dur- ing development affect reproductive investment of immature individuals. We investigated whether social conditions affected the length of the protandrous phase, body size and also the subsequent female fecundity of same-age protandrous individuals of O. diadema, which did not had to face competition for egg fertilization. Results show that in large group sizes protandrous males lengthened their protandrous phase, slowed down body growth and decreased their individual investment at the first egg laying compared to protandrous males that were reared in isolation. In the successive egg layings worms adjusted their egg output to the current social conditions. We interpreted these results as an indication that early social conditions represent a social stress result- ing in a reduction of the overall reproductive resources up to the first egg laying .展开更多
Objective:To evaluate the effects of ethanol extract of leaves of Helianthus annus(H.annus) on the fecundity of Wistar rats.Methods:Forty(20 male and 20 female) Wistar rats,grouped into control,ethanol extract treated...Objective:To evaluate the effects of ethanol extract of leaves of Helianthus annus(H.annus) on the fecundity of Wistar rats.Methods:Forty(20 male and 20 female) Wistar rats,grouped into control,ethanol extract treated rats and untreated,were used for the study.Treated rats had 0.5 g/kg of ethanol extract orally for 2 weeks;control rats had 5%alcoholic water(solvent);and untreated rats had their normal feed and clean drinking water.Following treatment,the animals were sub-grouped into 5 mating groups to observe the coital frequency,pregnancy rate and average number of pups per group in pairs.Results:The results showed that coital frequency was unaffected by the extract treatment but pregnancy rate and number of pups per rat and per group were reduced significantly in groupsⅡ,ⅢandⅣcompared to those of groupⅠandⅤrats which were not treated with the ethanol extract of leaves of H.annus.Conclusions:The histodegenerative in the gonads reportedly induced by this ethanol extract in previous studies may be responsible for the reduced fecundity observed in treated adult rats.展开更多
In this study,normal values of semen analysis were set for a general infertile population of couples among which most women had normal ovulation.The predictive capacity values of sperm quality,including concentration,...In this study,normal values of semen analysis were set for a general infertile population of couples among which most women had normal ovulation.The predictive capacity values of sperm quality,including concentration,motile count,progressive motile count,and morphology,are unclear for women with polycystic ovary syndrome(PCOS).A secondary analysis was conducted based on a randomized controlled trial investigating infertility among women with PCOS experiencing ovulatory disorder between 2011 and 2016 in China.A total of 1000 women received ovulation induction(acupuncture and clomiphene).We randomized the women with PCOS in 27 hospitals in China who received one of four interventions(acupuncture plus clomiphene,sham acupuncture plus clomiphene,acupuncture plus placebo,or sham acupuncture plus placebo).Semen analysis was performed for every male partner according to the World Health Organization(WHO)criteria.The outcomes included conception,clinical pregnancy,and live birth.Logistic regression was used to evaluate the predictive value of semen analysis among ovulatory women for conception,clinical pregnancy,and live birth.Among the 1000 couples,the number of couples who attained ovulation,conception,clinical pregnancy,and live birth were 780,320,235,and 205,respectively.Semen volume and motility were applied and used as prediction parameters for conception(area under the curve(AUC)of 0.62(95%confidence interval(CI),0.55–0.69)),clinical pregnancy(AUC of 0.67(95%CI:0.61–0.73)),and live birth(AUC of 0.57(95%CI:0.50–0.64)).No poor calibration was shown for these models in Hosmer–Lemeshow tests.The predictive capacity of semen analysis for treatment outcome in PCOS women with PCOS experiencing with ovulatory dysfunction is limited.展开更多
Both fecundities and egg hatchabilities were compared among three populations of Dastarcus helophoroides Fairmaire adults（Coleoptera： Bothrideridae） fed on three types of artificial diets（Diet of formula 1 compose...Both fecundities and egg hatchabilities were compared among three populations of Dastarcus helophoroides Fairmaire adults（Coleoptera： Bothrideridae） fed on three types of artificial diets（Diet of formula 1 composed of silkworm pupa powder, dried yeast powder,sucrose, peptone, egg yolk powder and poplar branch powder. Diet of formula 2 composed of silkworm pupa powder, dried yeast powder, sucrose, egg yolk powder,poplar branch powder, cricket powder, benzoic acid and distilled water. Diet of formula 3 composed of pine bark powder and Monochamus alternatus larva powder）. for90 days. The three diets showed no significant difference regarding the average number of eggs deposited by all D. helophoroides females（16622.3–23874.7）; the average number of eggs per female（1278.6–1836.5）; and the average number of eggs per female per day（14.2–20.4）.The number of eggs one cluster contained mainly（82.06–82.66 %） lied in 1–100 eggs, and the average number of eggs per cluster ranged from 61.7 to 63.1. In the first 10-day period, the number of eggs deposited by all females fed on formula 1 was significantly larger than that on formula 3. The eggs deposited in the last four 10-day periods were more than in the former five 10-day periods,on formula 3. There were no significant differences in hatchability of total eggs among the three artificial diets,and the average corrected egg hatchability ranged from82.85 to 84.78 %. No significant differences in the adult mortality and mean weight gain of D. helophoroides were found after feeding on three artificial diets. Our results suggest that D. helophoroides adults were not specialized on the diet, and the diet types might have little effect on fecundity and egg hatchability in D. helophoroides, as long as sufficient nutrition was supplied.展开更多
The paper aimed to study the effects of exogenous hormone on fecundity of silver fox. Vixens were timely injected with appropriate exogenous hormones at proper ratio to increase their ovulation and litter size, thereb...The paper aimed to study the effects of exogenous hormone on fecundity of silver fox. Vixens were timely injected with appropriate exogenous hormones at proper ratio to increase their ovulation and litter size, thereby improving the fecundity of silver fox. The average litter size in experimental group attained by 5.86 to 6.0 whelps, 1.61 - 1.75 whelps more than that in the control group. The hormone combination in the experimental group was high in performance/price ratio, which had no significant impact on fecundity of vixens in future.展开更多
The reproductive behavior of red palm weevil, Rhynchophorusferrugineus Olivier was studied in laboratory with several sets of unmated females paired with unmated males for different periods. The treatments in these co...The reproductive behavior of red palm weevil, Rhynchophorusferrugineus Olivier was studied in laboratory with several sets of unmated females paired with unmated males for different periods. The treatments in these controlled mating experiments included single mating, multiple mating for 24 h, multiple mating weekly, multiple mating on alternate days and multiple mating uninterrupted with a control group. During the study, observations were made on the number of eggs laid, incubation period, hatching percentage, ovipositional periods and adult longevity. Though unmated females laid a large number of eggs, these were infertile. This study clearly showed significant differences in the egg-laying capacity of females exposed to different frequencies of mating. The average number of eggs laid varied from 98.9 ± 9.7 eggs in a single-time mated female to 195.8± 24.3 eggs in females allowed to mate on alternate days throughout their life. As far as the percentage of egg-hatching is concerned, there were significant differences in single and multiple mated females with 22.4 ± 3.3% hatching in one time mated females as compared to 85.2 ± 1.9% in alternate day mated females. This study also showed direct impact of female matings on the number of eggs laid and their hatching percentage. Moreover, the unmated and mated female groups showed no significant differences in oviposition and post-ovipositional period and also there was very little difference in male and female adult longevity.展开更多
Aphid establishes colony in the selective plant parts like vine, leaf petiole, leaflet, inflorescence, and tender fruit in Dolichos lablab Linn but not the entire plant. In this study, the aphid colony establishment i...Aphid establishes colony in the selective plant parts like vine, leaf petiole, leaflet, inflorescence, and tender fruit in Dolichos lablab Linn but not the entire plant. In this study, the aphid colony establishment in vine is focused to understand the differential resistance response between two varieties. At the early stage of aphid infestation, the aphid colony establishment was significantly different between two genotypes (p value = 0.00) and abbreviated as “resistant” variety that supported lower aphid proliferation (mean value = 48.2 ± 2.2) and “susceptible” variety that supported comparatively higher aphid proliferation (mean value = 215.5 ± 16.9). The total aphid number was significantly different between the two varieties, realized at the early infestation stage when both “antixenosis” and “antibiosis” defense mechanisms were working on. Some plant specific factors like vine diameter, wet/ dry weight ratio of vine, phloem sap pressure, the compactness of the vine, wet/dry weight ratio of leaflet, length of leaf petiole, diameter of leaflet vein were identified as modulating factors. The impact of resistant variety on aphid was also investigated for better understanding of aphid defense mechanism.展开更多
In this study, artificially hatched Ocadia sinensis individuals were cultured for 60 months, to record the growth and development process and investigate the morphological characteristics between the sexes and individ...In this study, artificially hatched Ocadia sinensis individuals were cultured for 60 months, to record the growth and development process and investigate the morphological characteristics between the sexes and individual fecundity of O. sinensis. Results showed that the main morphological differences between male and female individuals are concentrated in secondary sexual characteristics ： female turtle individuals have flat or slightly prominent sternites, short tails, short length from anal pore to sternite trailing edge; male turtle individuals have concave sternites, relatively stout tails, large length from anal pore to sternite trailing edge. There were significant differences in the growth of male and female individuals, in the first 12 months, female individuals grew faster than male individuals, with greater carapace length, carapace width and weight, but the differences between male and female individuals were not significant; in the late stage, the growth rate of female individuals was much higher than that of male individuals; by the end of the experiment, the average weight of female individuals was 3.86 times of that of male individuals. Regression analysis of female fecundity showed that the clutch size of O. sinensis had significant regression relationship with carapace length and weight, the fertility of female individuals was improved with the increasing size （ carapace length and weight）.展开更多
In the present paper, a study of the productivity of oocytes in 402 female individuals of the horse mackerel, Trachurus trachurus for an interval of fork length （LF） between 14 cm and 20 cm, in stage IV （pre-spawn...In the present paper, a study of the productivity of oocytes in 402 female individuals of the horse mackerel, Trachurus trachurus for an interval of fork length （LF） between 14 cm and 20 cm, in stage IV （pre-spawning） and V （spawning） was performed to estimate the fecundity rate in Oran Bay （Algerian western coast） since October 2008 to April 2009. Total fecundity （absolute and relative） were calculated using fish length, weight and eviscerated weight of gonads. Absolute fecundity by size class oscillates from 33,375 to 56,391 eggs with an average of 48,686 ±11,470. The relative fecundity ranges from 34,802 to 139,636 eggs per 100 g body weight with an average of 96,955 ± 33,814 and it is varying between 15,544 and 46,561 per gram of gonad with an average of 28,595 ±20,251. The distribution of oocytes shows that stages I and II are presented throughout the spawning season and they constitute a stockpile for subsequent clutches.展开更多
This study was conducted to investigate the effect of different doses injection of human chorionic gonadotropin(HCG)hormone on fecundity and serum sex hormones(FSH,LH,estrogen(E2),progesterone(P4),testosterone(T))of A...This study was conducted to investigate the effect of different doses injection of human chorionic gonadotropin(HCG)hormone on fecundity and serum sex hormones(FSH,LH,estrogen(E2),progesterone(P4),testosterone(T))of African catfish(Clarias gariepinus).African catfish spawners were intermuscularly injected with different doses of HCG(500,1500,3000,6000 IU/kg female),and group is not injected as a control;males were injected at half the female dose.The results showed that,fish group injected by 6000 IU HCG/kg female had the highest gonadsomatic index,absolute fecundity and relative fecundity,while,the lowest value of absolute fecundity and relative fecundity were recorded with 500 IU HCG/kg female.The group injected with the highest amount of HCG(6000 IU/kg female)recorded the lowest value from egg diameter,while the highest egg diameter was observed in 500 IU HCG/kg female.In females,the group injected with 6000 IU HCG/kg female reflected the lowest level of FSH and the highest level of LH and the highest level of P4 compared to other treatments.Level of T recorded the highest level with 1500 IU HCG/kg female.The control group reflected the highest level of FSH and E2,while the control group reflected the lowest level of T and P4 level.In males,serum FSH,LH,P4 and E2 in male groups injected with HCG were relatively higher than those recorded in the control group.The highest level of T was recorded in treatment injected with the highest dose of HCG and decreased in other treatments until recorded the lowest level of T in the control group.It was observed,HCG hormone has successfully and accelerate induced spawning in African catfish(Clarias gariepinus)and increased in reproductive performance with the increase in HCG dosage and as compared to group not injected.展开更多
In order to exploit native fish species for aquaculture, basic parameters of artificial reproducetion and estimates of reproductive potential for this fish must be determined to improve hatchery success. We analyze se...In order to exploit native fish species for aquaculture, basic parameters of artificial reproducetion and estimates of reproductive potential for this fish must be determined to improve hatchery success. We analyze seven Brazilian commercial fish. Spawning was induced using the hypophysation method, with injection of crude carp pituitary extract (CCPE). Characiformes species signaled the spawning time with behavioral alterations (usually circular movements). The time of oocyte extrusion varied from 5.3 ± 0.3 h in Salminus franciscanus to 8.6 ± 0.1 h in Prochilodus argenteus after the second CCPE injection. The greatest diameter of a vitellogenic oocyte was registered for P. argenteus (873.9 ± 122.2 μm) and the smallest was for Pimelodus maculates (465.4 ± 36.3 μm). The diameter of vitellogenic oocytes was very similar among species belonging to the same family. The highest ROI values were registered for Prochilodus costatus(27.0 ± 3.5 μm) and P. argenteus (23.4 ± 3.7 μm), while the lowest values were found in Pseudoplatystoma corruscans (4.6 ± 0.9 μm) and P. maculatus (6.0 ± 1.3 μm). Absolute fecundity (number of oocytes released at spawning) was lowest in P. maculatus and highest in P. corruscans. Relative fecundity (RF) presented a high correlation (r = 0.98 to 0.99) with gonad weight, indicating high efficiency of spawning. The RF also presented a high correlation with body weight (r = 0.88 to 0.97) and total length (r = 0.86 to 0.92). The highest RF was registered for Leporinus obtusidens, and the lowest was for P. corruscans. Released fecundity had a negative correlation with the diameter of vitellogenic oocytes and with the height of the follicular cells, and a positive correlation with the thickness of the zona pelucida. These results indicate that the species studied herein are suitable candidates for aquaculture due to their reproductive and zootechnical characteristics.展开更多
Mounting evidence suggests that male sperm may be gradually depleted after consecutive matings,resulting in the decline of female reproductive output in insect species.It is predicted that females may employ adaptive ...Mounting evidence suggests that male sperm may be gradually depleted after consecutive matings,resulting in the decline of female reproductive output in insect species.It is predicted that females may employ adaptive strategies to avoid the sperm-depleted males,such as mating multiply with different males and/or discriminating against previously mated males(MMs).Similarly,males may exhibit adaptive behaviors toward females varying in mating status.However,in spiders with males lacking primary copulatory organs and their pedipalps modified to transfer sperm,there are few studies on male mating potential and previous mating experience on their subsequent mate choice.In this study,we used a polyandrous crab spider,Ebrechtella tricuspidata,a sit-and-wait predator with female-biased sex ratio as a model system to ascertain whether 1)male mating experiences influence female reproductive fitness;2)females respond differently to males varying in mating status;and 3)males respond differently to females varying in mating status.Our results showed that female fecundity was independent of male mating experiences,but female fertility markedly declined with the increase of male previous mating experiences in the first eggsac.Counter to our predictions,females preferred to choose and mate with the larger males,regardless of their mating status.In contrast,male mating status influenced their mating preference toward females.Virgin males did not show any preference between virgin and mated females;however,MMs were more likely to prefer the virgin females over the mated ones.Overall,our results indicated that female choice depended primarily on male relative size rather than male mating status,whereas male choice depended on female mating status,Depending on the investigation of reproductive dynamics and mate choice in E.tricuspidata,the study will provide valuable insights into the adaptive behaviors of both males and females exhibiting toward mates varying inmating status.展开更多
The red tilefish Branchiostegus japonicus is an economically important demersal fish species with high-quality.However,research on its reproductive biology and population structure characteristics is limited.To better...The red tilefish Branchiostegus japonicus is an economically important demersal fish species with high-quality.However,research on its reproductive biology and population structure characteristics is limited.To better understand the reproductive biological features of B.japonicus,a study was conducted on 461 individuals collected from the East China Sea(27°00′-31°00′N,122°30′-127°30′E)from March to December in 2021.This study analyzed the relationship between standard length and the body weight,and detected the sex ratio,length at first sexual maturity,reproductive period,fecundity,and spawning type of this species.The results revealed a power function relationship between body weight(W)and standard length(L)in the samples as the following regression equation:W=0.000014 L^(3.16)(R^(2)=0.956).The sex ratio was close to 1:1(χ^(2)=1.11,P>0.05),and the sex ratio exhibited significant differences according to different standard lengths.Using the logistic equation,we estimated that 50% of B.japonicus individuals had a standard length at sexual maturity of L_(50)=210 mm.By analyzing the monthly variation in the gonadal index and the proportion of each stage of ovarian development in each month,we assumed that the spawning period of B.japonicus occurred from May to November,and the peak spawning period occurred from June to October.The absolute fecundity was 51441±33232 eggs,the relative fecundity at the standard length was(210±117)eggs mm-1,and the relative fecundity relative to body weight was(184±89)eggs g^(-1).The distribution of the egg diameter of B.japonicus had only one obvious peak,indicating the spawning pattern of B.japonicus was once a year.This study updated and enriched the basic biological data of B.japonicus,which is beneficial for obtaining a better understanding of its population dynamics,and promoting the conservation and sustainable utilization of B.japonicus in East China Sea.展开更多
5-hydroxytryptamine(5-HT)is a biological monoamine neurotransmitter in the central nervous system and gonads of crustaceans to induce gonadal maturation.To better understand the effects of 5-HT and its receptors on re...5-hydroxytryptamine(5-HT)is a biological monoamine neurotransmitter in the central nervous system and gonads of crustaceans to induce gonadal maturation.To better understand the effects of 5-HT and its receptors on reproductive development in Artemia,a 5-HT type 7 receptor gene(5-HT_(7Ar))was identified in parthenogenetic Artemia and characterized.Sequence analysis revealed that the open reading frame of 5-HT_(7Ar) encodes a 414-aa protein.5-HT_(7Ar) showed higher expression in both brain and ovary at early embryo stage,5-HT_(7Ar) could be detected during ovarian development and the highest expression was observed at early embryo stage.Silencing of the 5-HT_(7Ar) in Artemia at early embryo stage decreased significantly the expression level of 5-HT_(7Ar) gene and protein at late oocyte,early embryo,and late embryo stage.Moreover,silencing of the 5-HT_(7Ar) resulted in a decreased fecundity,which corresponds to abnormal oocytes during the embryo development.Artemia tended to produce nauplii after the silencing of 5-HT_(7Ar),indicating that 5-HT_(7Ar) may also involve in the determination of its reproduction mode.The findings of this study provide an insight into the regulation of reproductive development in Artemia and the function of 5-HT_(7Ar).展开更多
基金supported in part by New Zealand Government core funding for Crown Research Institutes from the Ministry of Business,Innovation,and Employment's Science and Innovation Group.
文摘The nutritional status of an individual can significantly influence its life history traits,including development,growth,reproduction,and survival.In the predatory mite Phytoseiulus persimilis Athias-Henriot(Acari:Phytoseidae),the plasticity of life history traits,such as developmental time and size at maturity,is influenced by the quality and quantity of food.This study aimed to investigate the effects of dietary restriction at different life stages(i.e.,juvenile,early adulthood,and later adulthood)on the lifespan and fecundity of P persimilis.We found that reduced dietary intake during early adulthood resulted in a shorter lifespan for both male and female P persimilis.Furthermore,this study demonstrated a sex-specific response to dietary restriction:it extended the lifespan of males but reduced that of females during later adulthood.Diet restriction during the postovipositional period of females showed the most variable life history trait response.Our results showed that the impact of diet restriction at different life stages can have combined influences on the postovipositional duration of P persimilis,where the individuals receiving diet restriction during immature development and early adulthood had a greater reduction in ovipositional duration as those experiencing diet restriction during late adulthood.In addition,we observed a positive correlation between the lifespan and fecundity of females,with higher prey availability increasing both.The insights obtained from our research contribute to a better understanding of the aging process and dietary requirements of P persimilis,which can facilitate the development of more effective biological control strategies using this predator for spider mites in agriculture.
基金Supported by National Science Foundation of China(31171855)Special R&D Fund for Plant Epidemic Prevention and Quarantine in Guangdong Province(Yuenongji201190)~~
文摘[Objective] The aim was to study on the effect of hosts on development and reproduction of mealybug （Phenacoccus solenopsis Tinsley）. [Method] Observation was conducted on developmental durations and fecundity of Phenacoccus solenopsis Tinsley fed on Gossypium spp., Nicotiana tabacum, Solanum tuberosum L and Hibiscus rosa-sinensis. [Result] There were differences among all durations, generation durations and fecundities of the mealybug adult females. Specifically, the generation durations on cotton （Gossypium spp.）, tobacco（ Nicotiana tabacum）, potato （Solanum tuberosum L） and Hibiscus rosa-sinensis were 30.2, 28.2, 37.3, and 27.7 d, and the fecundities per female were 626.0, 417.2, 552.5, and 183.2 ind., respectively. [Conclusion] The mealybug would have strong pontential in population growth when fed on cotton, tobacco and potato.
文摘Several recent studies have shown that the fecundity of a man decreases progressively with sperm concentrations below 40 million spermatozoa per mL. Therefore, it is unfortunate that the new World Health Organization guidelines for semen analysis recommend lowering the lower cutoff value for normal sperm concentration from 20 to 15 million spermatozoa per mL. As a result large groups of subfertile men across the world may not receive appropriate andrological help in the future.
文摘Although amphioxus is widespread in temperate and tropical seas,its population is diminishing be-cause of environmental pollution.To keep the population of this evolutionarily important animal fromdiminishing,study on its reproduction and development is necessary.The main findings in this study onthe spawning and fecundity of the amphioxus reared in laboratory and its larval development are as fol-lows.1.Water temperature markedly affected the spawning.It spawned only when water temperature reached 21℃.2.Spawning of the amphioxus in laboratory was markedly extended.Initially,the amphioxus spawned at about 7:00 PM,but spawning time was postponed as spawning days went on.3.The number of eggs produced by a female ranged from 1400 to 12800,average of 5800.This al-so represents the fecundity of the amphioxus because it shedded all eggs within the ovary at a time.4.During the first few months of life of the amphioxus,its growth rate changed seasonally.Thegrowth rate in summer and fall was greater than that
基金Acknowledgments This study was supported by grants from the National Science Foundation of China （Project No. 30670281） and the Zhejiang Provincial Department of Education （Project No. Y200908723）. We thank Lai-Gao Luo, Long-Hui Lin, Yan-Fu Qu, Xi-Dong Zhang, Hong Li and Hong-Xia Liu for their help during the research.
文摘We used the Chinese skink Eumeces chinensis as a model animal to study the effects of tail loss on reproductive in- vestment and offspring traits. A total of 147 wild-captured adult females were divided into four groups according to their tail con- ditions. Tail breaks occurred most frequently in the proximal portion of the tail and least frequently in the distal portion, with the middle portion in between. This finding suggests that tail breaks occurring in nature often entails substantial energetic costs in E. chinensis where the tail is a major site of energy storage. The proportion of females that laid eggs was higher in females with in- tact or completely regenerated tails than in those with broken tails. Following whole-tail autotomy, the clutch size was reduced by 17%, and the clutch mass was reduced by 14%. Females undergoing substantial tail autotomy reduced reproductive investment, and they did so by reducing the number but not the size of eggs produced. None of the egg and hatchling traits was affected by tail loss. Comparing our data with those reported for other oviparous and viviparous skinks allows us to draw two general conclu- sions： one is that fecundity （clutch or litter size） is affected by tail loss in all species so far studied, whereas offspring size is af- fected by tail loss in some species, but not in others; the other is that the reduction in fecundity following tail loss is more evident in species lacking abdominal fat bodies
基金supported by the Key Realm Research and Development Program of Guangdong Province,China (Grant No. 2020B0202090001)the Foundation of Guangzhou Science and Technology Key Project,China (Grant No. 201904020041)
文摘MicroRNAs(miRNAs)can participate in plant-insect interactions,which regulate plant defense networks.In this study,we analyzed the miRNA expression profiles of six rice varieties before and after brown planthopper(BPH)-feeding.We identified 45 differentially expressed miRNAs between BPH-susceptible and BPH-resistant rice varieties and 144 miRNAs that responded to BPH-feeding.Thus,miRNAs may be involved in multiple pathways regulating rice defense response against BPH.In addition,we found that the genetic history of rice varieties determined the regulation mode of the miRNA and affected the amounts,types,changing trends and response periods of miRNAs in response to BPH-feeding.To conclude,we scanned seven potential cross-kingdom miRNAs,of which miR5795 may target the vitellogenin gene in BPH,causing a 16.07%reduction in BPH oviposition.The results provide new miRNA information of rice-BPH interactions and BPH-resistant rice variety breeding.
文摘Social conditions experienced prior to sexual maturity influence reproduction later in life in many animals. In simulta- neous hermaphrodites, variation in mating group size influences reproductive investment. As the mating group size increases, re- productive resources devoted to the female function decrease in favor of the male function. Prior to sexual maturity, many her- maphrodites have a protandrous phase during which they produce sperm and can fertilize hermaphrodites＇ eggs. In the simulta- neously hermaphroditic polychaete worm Ophryotrocha diadema, the cost of male reproduction during adolescence is spread over the whole energy budget of worms as shown by a reduced growth rate, a delayed age at sexual maturity and the shortening of life span compared to protandrous males that do not reproduce. Little is known on whether social conditions experienced dur- ing development affect reproductive investment of immature individuals. We investigated whether social conditions affected the length of the protandrous phase, body size and also the subsequent female fecundity of same-age protandrous individuals of O. diadema, which did not had to face competition for egg fertilization. Results show that in large group sizes protandrous males lengthened their protandrous phase, slowed down body growth and decreased their individual investment at the first egg laying compared to protandrous males that were reared in isolation. In the successive egg layings worms adjusted their egg output to the current social conditions. We interpreted these results as an indication that early social conditions represent a social stress result- ing in a reduction of the overall reproductive resources up to the first egg laying .
文摘Objective:To evaluate the effects of ethanol extract of leaves of Helianthus annus(H.annus) on the fecundity of Wistar rats.Methods:Forty(20 male and 20 female) Wistar rats,grouped into control,ethanol extract treated rats and untreated,were used for the study.Treated rats had 0.5 g/kg of ethanol extract orally for 2 weeks;control rats had 5%alcoholic water(solvent);and untreated rats had their normal feed and clean drinking water.Following treatment,the animals were sub-grouped into 5 mating groups to observe the coital frequency,pregnancy rate and average number of pups per group in pairs.Results:The results showed that coital frequency was unaffected by the extract treatment but pregnancy rate and number of pups per rat and per group were reduced significantly in groupsⅡ,ⅢandⅣcompared to those of groupⅠandⅤrats which were not treated with the ethanol extract of leaves of H.annus.Conclusions:The histodegenerative in the gonads reportedly induced by this ethanol extract in previous studies may be responsible for the reduced fecundity observed in treated adult rats.
基金This study was supported by the National Public Welfare Projects for Chinese Medicine(201107005)the National Key Research and Development Program of China(2019YFC1709500)+2 种基金the Project of Heilongjiang University of Chinese Medicine(2018RCQ12 and 2019BS09)the Projects of Heilongjiang Provincial Administration of Traditional Chinese medicine(ZHY2020-102)Xuzhou Clinical Medical Team Talent Introduction Project--Academician Yixun Liu Integrated Chinese and Western medicine,Maternity and Reproductive Technology Innovation Team,and Academician Yixun Liu Workstation Project.
文摘In this study,normal values of semen analysis were set for a general infertile population of couples among which most women had normal ovulation.The predictive capacity values of sperm quality,including concentration,motile count,progressive motile count,and morphology,are unclear for women with polycystic ovary syndrome(PCOS).A secondary analysis was conducted based on a randomized controlled trial investigating infertility among women with PCOS experiencing ovulatory disorder between 2011 and 2016 in China.A total of 1000 women received ovulation induction(acupuncture and clomiphene).We randomized the women with PCOS in 27 hospitals in China who received one of four interventions(acupuncture plus clomiphene,sham acupuncture plus clomiphene,acupuncture plus placebo,or sham acupuncture plus placebo).Semen analysis was performed for every male partner according to the World Health Organization(WHO)criteria.The outcomes included conception,clinical pregnancy,and live birth.Logistic regression was used to evaluate the predictive value of semen analysis among ovulatory women for conception,clinical pregnancy,and live birth.Among the 1000 couples,the number of couples who attained ovulation,conception,clinical pregnancy,and live birth were 780,320,235,and 205,respectively.Semen volume and motility were applied and used as prediction parameters for conception(area under the curve(AUC)of 0.62(95%confidence interval(CI),0.55–0.69)),clinical pregnancy(AUC of 0.67(95%CI:0.61–0.73)),and live birth(AUC of 0.57(95%CI:0.50–0.64)).No poor calibration was shown for these models in Hosmer–Lemeshow tests.The predictive capacity of semen analysis for treatment outcome in PCOS women with PCOS experiencing with ovulatory dysfunction is limited.
基金supported by the National Natural Science Foundation of China(31300547)the Anhui Provincial Natural Science Foundation(1208085QC72)the Anhui Provincial Science and Technology Program(10010302001)
文摘Both fecundities and egg hatchabilities were compared among three populations of Dastarcus helophoroides Fairmaire adults（Coleoptera： Bothrideridae） fed on three types of artificial diets（Diet of formula 1 composed of silkworm pupa powder, dried yeast powder,sucrose, peptone, egg yolk powder and poplar branch powder. Diet of formula 2 composed of silkworm pupa powder, dried yeast powder, sucrose, egg yolk powder,poplar branch powder, cricket powder, benzoic acid and distilled water. Diet of formula 3 composed of pine bark powder and Monochamus alternatus larva powder）. for90 days. The three diets showed no significant difference regarding the average number of eggs deposited by all D. helophoroides females（16622.3–23874.7）; the average number of eggs per female（1278.6–1836.5）; and the average number of eggs per female per day（14.2–20.4）.The number of eggs one cluster contained mainly（82.06–82.66 %） lied in 1–100 eggs, and the average number of eggs per cluster ranged from 61.7 to 63.1. In the first 10-day period, the number of eggs deposited by all females fed on formula 1 was significantly larger than that on formula 3. The eggs deposited in the last four 10-day periods were more than in the former five 10-day periods,on formula 3. There were no significant differences in hatchability of total eggs among the three artificial diets,and the average corrected egg hatchability ranged from82.85 to 84.78 %. No significant differences in the adult mortality and mean weight gain of D. helophoroides were found after feeding on three artificial diets. Our results suggest that D. helophoroides adults were not specialized on the diet, and the diet types might have little effect on fecundity and egg hatchability in D. helophoroides, as long as sufficient nutrition was supplied.
文摘The paper aimed to study the effects of exogenous hormone on fecundity of silver fox. Vixens were timely injected with appropriate exogenous hormones at proper ratio to increase their ovulation and litter size, thereby improving the fecundity of silver fox. The average litter size in experimental group attained by 5.86 to 6.0 whelps, 1.61 - 1.75 whelps more than that in the control group. The hormone combination in the experimental group was high in performance/price ratio, which had no significant impact on fecundity of vixens in future.
文摘The reproductive behavior of red palm weevil, Rhynchophorusferrugineus Olivier was studied in laboratory with several sets of unmated females paired with unmated males for different periods. The treatments in these controlled mating experiments included single mating, multiple mating for 24 h, multiple mating weekly, multiple mating on alternate days and multiple mating uninterrupted with a control group. During the study, observations were made on the number of eggs laid, incubation period, hatching percentage, ovipositional periods and adult longevity. Though unmated females laid a large number of eggs, these were infertile. This study clearly showed significant differences in the egg-laying capacity of females exposed to different frequencies of mating. The average number of eggs laid varied from 98.9 ± 9.7 eggs in a single-time mated female to 195.8± 24.3 eggs in females allowed to mate on alternate days throughout their life. As far as the percentage of egg-hatching is concerned, there were significant differences in single and multiple mated females with 22.4 ± 3.3% hatching in one time mated females as compared to 85.2 ± 1.9% in alternate day mated females. This study also showed direct impact of female matings on the number of eggs laid and their hatching percentage. Moreover, the unmated and mated female groups showed no significant differences in oviposition and post-ovipositional period and also there was very little difference in male and female adult longevity.
文摘Aphid establishes colony in the selective plant parts like vine, leaf petiole, leaflet, inflorescence, and tender fruit in Dolichos lablab Linn but not the entire plant. In this study, the aphid colony establishment in vine is focused to understand the differential resistance response between two varieties. At the early stage of aphid infestation, the aphid colony establishment was significantly different between two genotypes (p value = 0.00) and abbreviated as “resistant” variety that supported lower aphid proliferation (mean value = 48.2 ± 2.2) and “susceptible” variety that supported comparatively higher aphid proliferation (mean value = 215.5 ± 16.9). The total aphid number was significantly different between the two varieties, realized at the early infestation stage when both “antixenosis” and “antibiosis” defense mechanisms were working on. Some plant specific factors like vine diameter, wet/ dry weight ratio of vine, phloem sap pressure, the compactness of the vine, wet/dry weight ratio of leaflet, length of leaf petiole, diameter of leaflet vein were identified as modulating factors. The impact of resistant variety on aphid was also investigated for better understanding of aphid defense mechanism.
基金Supported by Project of Science and Technology of Guangdong Province(2010B020410004)Project of Science and Technology for Universities and Research Institutes of Dongguan City(201010810113)
文摘In this study, artificially hatched Ocadia sinensis individuals were cultured for 60 months, to record the growth and development process and investigate the morphological characteristics between the sexes and individual fecundity of O. sinensis. Results showed that the main morphological differences between male and female individuals are concentrated in secondary sexual characteristics ： female turtle individuals have flat or slightly prominent sternites, short tails, short length from anal pore to sternite trailing edge; male turtle individuals have concave sternites, relatively stout tails, large length from anal pore to sternite trailing edge. There were significant differences in the growth of male and female individuals, in the first 12 months, female individuals grew faster than male individuals, with greater carapace length, carapace width and weight, but the differences between male and female individuals were not significant; in the late stage, the growth rate of female individuals was much higher than that of male individuals; by the end of the experiment, the average weight of female individuals was 3.86 times of that of male individuals. Regression analysis of female fecundity showed that the clutch size of O. sinensis had significant regression relationship with carapace length and weight, the fertility of female individuals was improved with the increasing size （ carapace length and weight）.
文摘In the present paper, a study of the productivity of oocytes in 402 female individuals of the horse mackerel, Trachurus trachurus for an interval of fork length （LF） between 14 cm and 20 cm, in stage IV （pre-spawning） and V （spawning） was performed to estimate the fecundity rate in Oran Bay （Algerian western coast） since October 2008 to April 2009. Total fecundity （absolute and relative） were calculated using fish length, weight and eviscerated weight of gonads. Absolute fecundity by size class oscillates from 33,375 to 56,391 eggs with an average of 48,686 ±11,470. The relative fecundity ranges from 34,802 to 139,636 eggs per 100 g body weight with an average of 96,955 ± 33,814 and it is varying between 15,544 and 46,561 per gram of gonad with an average of 28,595 ±20,251. The distribution of oocytes shows that stages I and II are presented throughout the spawning season and they constitute a stockpile for subsequent clutches.
文摘This study was conducted to investigate the effect of different doses injection of human chorionic gonadotropin(HCG)hormone on fecundity and serum sex hormones(FSH,LH,estrogen(E2),progesterone(P4),testosterone(T))of African catfish(Clarias gariepinus).African catfish spawners were intermuscularly injected with different doses of HCG(500,1500,3000,6000 IU/kg female),and group is not injected as a control;males were injected at half the female dose.The results showed that,fish group injected by 6000 IU HCG/kg female had the highest gonadsomatic index,absolute fecundity and relative fecundity,while,the lowest value of absolute fecundity and relative fecundity were recorded with 500 IU HCG/kg female.The group injected with the highest amount of HCG(6000 IU/kg female)recorded the lowest value from egg diameter,while the highest egg diameter was observed in 500 IU HCG/kg female.In females,the group injected with 6000 IU HCG/kg female reflected the lowest level of FSH and the highest level of LH and the highest level of P4 compared to other treatments.Level of T recorded the highest level with 1500 IU HCG/kg female.The control group reflected the highest level of FSH and E2,while the control group reflected the lowest level of T and P4 level.In males,serum FSH,LH,P4 and E2 in male groups injected with HCG were relatively higher than those recorded in the control group.The highest level of T was recorded in treatment injected with the highest dose of HCG and decreased in other treatments until recorded the lowest level of T in the control group.It was observed,HCG hormone has successfully and accelerate induced spawning in African catfish(Clarias gariepinus)and increased in reproductive performance with the increase in HCG dosage and as compared to group not injected.
基金This study was conducted with funds granted by CNPq,FAPEMIG and CODEVASF.
文摘In order to exploit native fish species for aquaculture, basic parameters of artificial reproducetion and estimates of reproductive potential for this fish must be determined to improve hatchery success. We analyze seven Brazilian commercial fish. Spawning was induced using the hypophysation method, with injection of crude carp pituitary extract (CCPE). Characiformes species signaled the spawning time with behavioral alterations (usually circular movements). The time of oocyte extrusion varied from 5.3 ± 0.3 h in Salminus franciscanus to 8.6 ± 0.1 h in Prochilodus argenteus after the second CCPE injection. The greatest diameter of a vitellogenic oocyte was registered for P. argenteus (873.9 ± 122.2 μm) and the smallest was for Pimelodus maculates (465.4 ± 36.3 μm). The diameter of vitellogenic oocytes was very similar among species belonging to the same family. The highest ROI values were registered for Prochilodus costatus(27.0 ± 3.5 μm) and P. argenteus (23.4 ± 3.7 μm), while the lowest values were found in Pseudoplatystoma corruscans (4.6 ± 0.9 μm) and P. maculatus (6.0 ± 1.3 μm). Absolute fecundity (number of oocytes released at spawning) was lowest in P. maculatus and highest in P. corruscans. Relative fecundity (RF) presented a high correlation (r = 0.98 to 0.99) with gonad weight, indicating high efficiency of spawning. The RF also presented a high correlation with body weight (r = 0.88 to 0.97) and total length (r = 0.86 to 0.92). The highest RF was registered for Leporinus obtusidens, and the lowest was for P. corruscans. Released fecundity had a negative correlation with the diameter of vitellogenic oocytes and with the height of the follicular cells, and a positive correlation with the thickness of the zona pelucida. These results indicate that the species studied herein are suitable candidates for aquaculture due to their reproductive and zootechnical characteristics.
基金the National Natural Science Foundation of China(30800121).
文摘Mounting evidence suggests that male sperm may be gradually depleted after consecutive matings,resulting in the decline of female reproductive output in insect species.It is predicted that females may employ adaptive strategies to avoid the sperm-depleted males,such as mating multiply with different males and/or discriminating against previously mated males(MMs).Similarly,males may exhibit adaptive behaviors toward females varying in mating status.However,in spiders with males lacking primary copulatory organs and their pedipalps modified to transfer sperm,there are few studies on male mating potential and previous mating experience on their subsequent mate choice.In this study,we used a polyandrous crab spider,Ebrechtella tricuspidata,a sit-and-wait predator with female-biased sex ratio as a model system to ascertain whether 1)male mating experiences influence female reproductive fitness;2)females respond differently to males varying in mating status;and 3)males respond differently to females varying in mating status.Our results showed that female fecundity was independent of male mating experiences,but female fertility markedly declined with the increase of male previous mating experiences in the first eggsac.Counter to our predictions,females preferred to choose and mate with the larger males,regardless of their mating status.In contrast,male mating status influenced their mating preference toward females.Virgin males did not show any preference between virgin and mated females;however,MMs were more likely to prefer the virgin females over the mated ones.Overall,our results indicated that female choice depended primarily on male relative size rather than male mating status,whereas male choice depended on female mating status,Depending on the investigation of reproductive dynamics and mate choice in E.tricuspidata,the study will provide valuable insights into the adaptive behaviors of both males and females exhibiting toward mates varying inmating status.
基金funded by the Key Technology and System Exploration of Quota Fishing,Ministry of Agriculture and Rural Affairs,Fishery Management Fund Project(No.36,2017)the Zhejiang Fishery Resources Survey Special Project(No.HYS-CZ-202314)。
文摘The red tilefish Branchiostegus japonicus is an economically important demersal fish species with high-quality.However,research on its reproductive biology and population structure characteristics is limited.To better understand the reproductive biological features of B.japonicus,a study was conducted on 461 individuals collected from the East China Sea(27°00′-31°00′N,122°30′-127°30′E)from March to December in 2021.This study analyzed the relationship between standard length and the body weight,and detected the sex ratio,length at first sexual maturity,reproductive period,fecundity,and spawning type of this species.The results revealed a power function relationship between body weight(W)and standard length(L)in the samples as the following regression equation:W=0.000014 L^(3.16)(R^(2)=0.956).The sex ratio was close to 1:1(χ^(2)=1.11,P>0.05),and the sex ratio exhibited significant differences according to different standard lengths.Using the logistic equation,we estimated that 50% of B.japonicus individuals had a standard length at sexual maturity of L_(50)=210 mm.By analyzing the monthly variation in the gonadal index and the proportion of each stage of ovarian development in each month,we assumed that the spawning period of B.japonicus occurred from May to November,and the peak spawning period occurred from June to October.The absolute fecundity was 51441±33232 eggs,the relative fecundity at the standard length was(210±117)eggs mm-1,and the relative fecundity relative to body weight was(184±89)eggs g^(-1).The distribution of the egg diameter of B.japonicus had only one obvious peak,indicating the spawning pattern of B.japonicus was once a year.This study updated and enriched the basic biological data of B.japonicus,which is beneficial for obtaining a better understanding of its population dynamics,and promoting the conservation and sustainable utilization of B.japonicus in East China Sea.
基金Supported by the Tianjin Key Laboratory of Marine Resources and Chemistry(Tianjin University of Science&Technology),Tianjin,China(No.202302)the National Natural Science Foundation of China(No.32460154)the China Postdoctoral Science Foundation(No.2023MD734227)。
文摘5-hydroxytryptamine(5-HT)is a biological monoamine neurotransmitter in the central nervous system and gonads of crustaceans to induce gonadal maturation.To better understand the effects of 5-HT and its receptors on reproductive development in Artemia,a 5-HT type 7 receptor gene(5-HT_(7Ar))was identified in parthenogenetic Artemia and characterized.Sequence analysis revealed that the open reading frame of 5-HT_(7Ar) encodes a 414-aa protein.5-HT_(7Ar) showed higher expression in both brain and ovary at early embryo stage,5-HT_(7Ar) could be detected during ovarian development and the highest expression was observed at early embryo stage.Silencing of the 5-HT_(7Ar) in Artemia at early embryo stage decreased significantly the expression level of 5-HT_(7Ar) gene and protein at late oocyte,early embryo,and late embryo stage.Moreover,silencing of the 5-HT_(7Ar) resulted in a decreased fecundity,which corresponds to abnormal oocytes during the embryo development.Artemia tended to produce nauplii after the silencing of 5-HT_(7Ar),indicating that 5-HT_(7Ar) may also involve in the determination of its reproduction mode.The findings of this study provide an insight into the regulation of reproductive development in Artemia and the function of 5-HT_(7Ar).
