The stability and evolution of human genetics depend on chromosomes and chromosome-chromosome interactions.We wish to understand the spatial location of chromosomes in dividing cells in order to understand the relatio...The stability and evolution of human genetics depend on chromosomes and chromosome-chromosome interactions.We wish to understand the spatial location of chromosomes in dividing cells in order to understand the relationship between chromosome-chromosome interactions and to further investigate the role of chromosomes and their impact on cell biological behavior.In this study,we explored the relative spatial positional relationships of chromosomes[t(9;22)and t(15;17)]in B-ALL cells by using the three-dimensional DNA fluorescent in situ hybridization(3D-FISH)method.The results showed that chromosomes[t(9;22)and t(15;17)]showed relatively stable spatial relationships.The relative stability of the spatial location of chromosomes in dividing cells may be relevant to disease.展开更多
Purpose:Derivative chromosomes,resulting from complex structural rearrangements,pose significant challenges in prenatal diagnosis due to their unpredictable inheritance patterns and potential phenotypic consequences.T...Purpose:Derivative chromosomes,resulting from complex structural rearrangements,pose significant challenges in prenatal diagnosis due to their unpredictable inheritance patterns and potential phenotypic consequences.This study evaluates the efficacy of multiple genetic technologies-including karyotyping,fluorescence in situ hybridization(FISH),chromosomal microarray analysis(CMA),and next-generation sequencing(NGS)-in detecting and characterizing derivative chromosomes in prenatal samples.methodology:We analyzed 150 cases of suspected chromosomal abnormalities,comparing detection rates,resolution,and clinical utility across these methods.Results:Our findings demonstrate that integrated multi-technology approaches significantly improve diagnostic accuracy,with NGS-based structural variation analysis achieving the highest detection sensitivity(99.2%)for cryptic rearrangements.Conclusions:Additionally,long-read sequencing(PacBio/Oxford Nanopore)enabled precise breakpoint mapping in 92%of cases,facilitating more accurate genetic counseling.Clinically,this approach enhances risk assessment for fetal anomalies,guides pregnancy management,and improves parental counseling for recurrence risks.展开更多
The objective of this study is to quantitatively reveal the main genetic carrier of antibiotic resistance genes(ARGs)for blocking their environmental dissemination.The distribution of ARGs in chromosomes,plasmids,and ...The objective of this study is to quantitatively reveal the main genetic carrier of antibiotic resistance genes(ARGs)for blocking their environmental dissemination.The distribution of ARGs in chromosomes,plasmids,and phages for understanding their respective contributions to the development of antimicrobial resistance in aerobic biofilm consortium under increasing stresses of oxytetracycline,streptomycin,and tigecyclinewere revealed based on metagenomics analysis.Results showed that the plasmids harbored 49.2%-83.9%of resistomes,which was higher(p<0.001)than chromosomes(2.0%-35.6%),and no ARGs were detected in phage contigs under the strict alignment standard of over 80%identity used in this study.Plasmids and chromosomes tended to encode different types of ARGs,whose abundances all increased with the hike of antibiotic concentrations,and the variety of ARGs encoded by plasmids(14 types and 64 subtypes)was higher than that(11 types and 27 subtypes)of chromosomes.The dosing of the three antibiotics facilitated the transposition and recombination of ARGs on plasmids,mediated by transposable and integrable transfer elements,which increased the co-occurrence of associated and unassociated ARGs.The results quantitatively proved that plasmids dominate the proliferation of ARGs in aerobic biofilm driven by antibiotic selection,which should be a key target for blocking ARG dissemination.展开更多
BACKGROUND Hepatocellular carcinoma(HCC)ranks among the most prevalent and deadly malignancies,characterized by a high recurrence rate.Regulator of chromosome condensation 1(RCC1)serves as a principal guanine nucleoti...BACKGROUND Hepatocellular carcinoma(HCC)ranks among the most prevalent and deadly malignancies,characterized by a high recurrence rate.Regulator of chromosome condensation 1(RCC1)serves as a principal guanine nucleotide exchange factor for ras-related nuclear protein guanosine triphosphatase(GTPase)and is implicated in various cancers.However,the role of RCC1 in HCC remains unex-plored.AIM To elucidate the functional significance and molecular mechanisms of RCC1 in HCC.METHODS Bioinformatics were to examine the expression levels of RCC1 in HCC and to assess its impact on the prognosis of this malignancy.The cell counting kit-8 assay and flow cytometry were utilized to evaluate the cell viability and cell cycle of HCC cells.Furthermore,quantitative reverse transcription and immunoblotting were to investigate the influence of RCC1 on cyclin associated proteins.RESULTS Bioinformatics analysis revealed that RCC1 was highly expressed in HCC and correlated with poor prognosis in HCC patients.Functional studies showed that RCC1 overexpression promoted the malignant phenotype of HCC cells,especially the proliferation of HCC cells,whereas RCC1 knockdown had the opposite effect.Mechanistically,we identied cell division cycle-associated(CDCA)8 as a downstream target of RCC1 in HCC.RCC1 overexpression markedly increased CDCA8 levels,consequently enhancing cell proliferation and survival in HCC cells.Additionally,we discovered that RCC1 contributed to the development and progression of HCC by activating the phosphoinositide 3-kinase/protein kinase B/cyclin-dependent kinase inhibitor 1a pathway through CDCA8.CONCLUSION Our study provides profound insights into the pivotal role of RCC1 in HCC and its potential as a therapeutic target.展开更多
Fusarium head blight(FHB)threatens wheat production worldwide.Utilization of FHB resistant varieties is the most effective solution for disease control.Owing to the limited sources of FHB resistance,mining of novel re...Fusarium head blight(FHB)threatens wheat production worldwide.Utilization of FHB resistant varieties is the most effective solution for disease control.Owing to the limited sources of FHB resistance,mining of novel resistance genes is crucial.Here,we report an FHB resistance gene from a wild wheat relative species,Roegneria ciliaris and developed FHB resistant germplasm containing this gene.Wheat-R.ciliaris disomic addition line DA3S^(c) showed enhanced type II FHB resistance compared to its sister line 3S^(c)-Null without chromosome 3S^(c),indicating that the resistance was contributed by the addition of 3S^(c).The resistance gene on 3S^(c) was validated using F_(2) and F_(2:3) populations derived from the cross between DA3S^(c) and susceptible Aikang 58(a susceptible cultivar),demonstrating that the lines with 3S^(c) had significantly enhanced FHB resistance compared to the individuals without 3S^(c).This was the second resistance gene identified in R.ciliaris,designated FhbRc2.To transfer FhbRc2 to common wheat,we produced a doublemonosomic chromosome population by crossing DA3S^(c) with the Chinese Spring nulli-tetrasomic line N3DT3B.Eight alien chromosome lines containing 3S^(c) were identified using genomic/fluorescence in situ hybridization and 3S^(c)-specific marker analysis.Only the lines carrying the long arm of 3S^(c) conferred FHB resistance,further locating FhbRc2 on 3S^(c)L.A compensating wheat-R.ciliaris Robertsonian translocation line T3DS·3S^(c)L harboring FhbRc2 is developed and provides a potential genetic resource in wheat breeding for enhanced FHB resistance.展开更多
Sugarcane has recently attracted increasing attention for its potential as a source of sugar and bioethanol,so increasing its yield is essential to ensure the sugar security and bioenergy production.Intergeneric hybri...Sugarcane has recently attracted increasing attention for its potential as a source of sugar and bioethanol,so increasing its yield is essential to ensure the sugar security and bioenergy production.Intergeneric hybridization is a highly efficient method to produce new genetic variants of crop plants,particularly those species with high ploidy such as sugarcane(Saccharum spp.).Tripidium arundinaceum exhibits many desirable agronomic traits,and has been widely studied to produce hybrids with improved stress tolerance and other characteristics in sugarcane breeding.However,the genetic relationship between T.arundinaceum and Saccharum species,and the individual T.arundinaceum chromosomal compositions in sugarcane hybrids are still elusive.Here we used whole-genome single-nucleotide polymorphisms(SNPs)to ascertain the phylogenetic relationships between these species and found that T.arundinaceum is more closely related to Saccharum than Sorghum,in contrast to the previous narrow genetic analyses using chloroplast DNA.Additionally,oligonucleotide(oligo)-based chromosome-specific painting derived from Saccharum officinarum was able to distinctly identify the chromosomes of T.arundinaceum.We developed the oligo-genomic in situ hybridization(GISH)system for the first time,to unveil the novel chromosome translocations and the transmission of individual T.arundinaceum chromosomes in sugarcane progeny.Notably,we discovered that the chromosomal transmission of T.arundinaceum exhibited several different inheritance modes,including n,2n,and over 2n in the BC1 progenies.Such inheritance patterns may have resulted from first division restitution(FDR)or FDR+nondisjunction of a chromosome with the sister chromatids in the second meiosis division/second division restitution(FDR+NSC/SDR)model during meiosis.These results will be of substantial benefit for the further selection of T.arundinaceum chromosomes for sugarcane genetic improvement.展开更多
Meiosis is the process of producing haploid gametes through a series of complex chromosomal events and the coordinated action of various proteins.The mitochondrial protease complex(ClpXP),which consists of caseinolyti...Meiosis is the process of producing haploid gametes through a series of complex chromosomal events and the coordinated action of various proteins.The mitochondrial protease complex(ClpXP),which consists of caseinolytic mitochondrial matrix peptidase X(ClpX)and caseinolytic protease P(ClpP)and mediates the degradation of misfolded,damaged,and oxidized proteins,is essential for maintaining mitochondrial homeostasis.ClpXP has been implicated in meiosis regulation,but its precise role is currently unknown.In this study,we engineered an inducible male germ cell-specific knockout caseinolytic mitochondrial matrix peptidase X(Clpx^(cKO))mouse model to investigate the function of ClpX in meiosis.We found that disrupting Clpx in male mice induced germ cell apoptosis and led to an absence of sperm in the epididymis.Specifically,it caused asynapsis of homologous chromosomes and impaired meiotic recombination,resulting in meiotic arrest in the zygotene-to-pachytene transition phase.The loss of ClpX compromised the double-strand break(DSB)repair machinery by markedly reducing the recruitment of DNA repair protein RAD51 homolog 1(RAD51)to DSB sites.This dysfunction may be due to an insufficient supply of energy from the aberrant mitochondria in Clpx^(cKO) spermatocytes,as discerned by electron microscopy.Furthermore,ubiquitination signals on chromosomes and the expression of oxidative phosphorylation subunits were both significantly attenuated in Clpx^(cKO) spermatocytes.Taken together,we propose that ClpX is essential for maintaining mitochondrial protein homeostasis and ensuring homologous chromosome pairing,synapsis,and recombination in spermatocytes during meiotic prophase I.展开更多
The impact of sex chromosomes and their turnover in speciation remains a subject of ongoing debate in the field of evolutionary biology.Fishes are the largest group of vertebrates,and they exhibit unparalleled sexual ...The impact of sex chromosomes and their turnover in speciation remains a subject of ongoing debate in the field of evolutionary biology.Fishes are the largest group of vertebrates,and they exhibit unparalleled sexual plasticity,as well as diverse sex-determining(SD)genes,sex chromosomes,and sex-determination mechanisms.This diversity is hypothesized to be associated with the frequent turnover of sex chromosomes in fishes.Although it is evident that amh and amhr2 are repeatedly and independently recruited as SD genes,their relationship with the rapid turnover of sex chromosomes and the biodiversity of fishes remains unknown.We summarize the canonical models of sex chromosome turnover and highlight the vital roles of gene mutation and hybridization with empirical evidence.We revisit Haldane’s rule and the large Xeffect and propose the hypothesis that sex chromosomes accelerate speciation by multiplying genotypes via hybridization.By integrating recent findings on the turnover of SD genes,sex chromosomes,and sexdetermination systems in fish species,this review provides insights into the relationship between sex chromosome evolution and biodiversity in fishes.展开更多
Doubled haploid(DH)technology is an efficient method used in commercial maize breeding.Chromosome doubling is a vital step of DH technology;however,the underlying processes regulating chromosome doubling of haploid is...Doubled haploid(DH)technology is an efficient method used in commercial maize breeding.Chromosome doubling is a vital step of DH technology;however,the underlying processes regulating chromosome doubling of haploid is still not well understood,which is key to optimize the technology.In this study,the immature haploid embryos of the maize inbred line Zheng58 treated with amiprophos-methyl(APM)or colchicine were used to analyze transcriptomic and metabolomic changes,75 and 60 differential expressed metabolites(DEMs)were identified between control treatment,respectively.Most differentially expressed genes(DEGs)related to artificial chromosome doubling were down regulated;these were mainly involved in mitosis process.Both DEMs and DEGs co-expression analyses showed that,compared to controls,zeatin biosynthesis and cofactor and vitamin metabolism were significantly enriched in both APM and colchicine treatments.In a parallel experiment,exogenous vitamins including thiamine,nicotinic acid,vitamin B6,or trans-zeatin were added to colchicine treatment;there were synergistic effects between vitamins or zeatin and colchicine in haploid artificial chromosome doubling.These results provide novel insights in exploring the molecular responses to antimitotic reagents at both the transcriptomic and metabolomic levels.In addition,the application efficiency of haploid breeding will be greatly improved by the key factors for artificial chromosome doubling.展开更多
Genetic pest control strategies based on precise sex separation and only releasing sterile males can be accomplished by site-specific genome editing.In the current study,we showed that the mutation of single-allele Px...Genetic pest control strategies based on precise sex separation and only releasing sterile males can be accomplished by site-specific genome editing.In the current study,we showed that the mutation of single-allele Pxfl(2)d can significantly impair the normal mating behavior and testis development in male adults of the notorious cruciferous insect pest Plutella xylostella,in addition to its known functions in the ovarian development in female adults and egg hatching.Subsequent CRISPR/Cas9-based knock-in experiments revealed that site-specific integration of an exogenous green fluorescent protein(GFP)gene into autosomal Pxfl(2)d for labelling mutants could be achieved.However,this gene is not a suitable target for GFP insertion to establish a genetically stable knock-in strain because of the severe decline in reproductive capacity.We further screened for the W-chromosome-linked and Z-chromosome-linked regions to test the knock-in efficiency mediated by CRISPR/Cas9.The results verified that both types of chromosomes can be targeted for the site-specific insertion of exogenous sequences.We ultimately obtained a homozygous knock-in strain with the integration of both Cas9 and cyan fluorescent protein(CFP)expression cassettes on a Z-linked region in P.xylostella,which can also be used for early sex detection.By injecting the sgRNA targeting Pxfl(2)d alone into the eggs laid by female adults of the Z-Cas9-CFP strain,the gene editing efficiency reached 29.73%,confirming the success of expressing a functional Cas9 gene.Taken together,we demonstrated the feasibility of the knock-in of an exogenous gene to different genomic regions in P.xylostella,while the establishment of a heritable strain required the positioning of appropriate sites.This study provides an important working basis and technical support for further developing genetic strategies for insect pest control.展开更多
The identification of sex chromosomes is fundamental for exploring the mechanism and evolution of sex determination.Platichthys stellatus,a species exhibiting clear sexual dimorphism and homomorphic chromosome pairs,h...The identification of sex chromosomes is fundamental for exploring the mechanism and evolution of sex determination.Platichthys stellatus,a species exhibiting clear sexual dimorphism and homomorphic chromosome pairs,has received limited research concerning its sex determination mechanisms.Clarifying the sex chromosome of P.stellatus will enhance our understanding of sex chromosome evolution in Pleuronectiformes.This study employed whole-genome resequencing to investigate the sex chromosome and sex determination system in P.stellatus.Notably,Chr23 was identified as the sex chromosome in P.stellatus,with the sex-determining region(SDR)occupying 48.1%of the chromosome and featuring an XX/XY system.Sex chromosome turnover was observed within Pleuronectiformes,with P.stellatus,Verasper variegatus,and Hippoglossus hippoglossus sharing a common ancestral karyotype.No inversions were detected within the SDR of P.stellatus,although chromosomal rearrangements between sex chromosomes and autosomes were identified.Additionally,a sex-specific marker for P.stellatus was ascertained,enabling genetic sex identification,with significant implications for improving breeding programs and aquaculture practices.展开更多
Pericentric inversion of chromosome 9(inv[9])is a common chromosomal structural variant,but its impact on clinical outcomesremains debated.The screening criteria of sperm banks are rarely mentioned to individuals with...Pericentric inversion of chromosome 9(inv[9])is a common chromosomal structural variant,but its impact on clinical outcomesremains debated.The screening criteria of sperm banks are rarely mentioned to individuals with inv(9).In this study,we evaluatedthe fertility of sperm donors with inv(9)who met eligibility criteria for sperm banks(inv[9]-eligible donors).From March 2004 toMay 2022,chromosomal analysis of 16124 sperm donors at CITIC-Xiangya Human Sperm Bank in Hunan Province(Changsha,China)found that 251(1.6%)had chromosome variations,with inv(9)being the most prevalent at 1.1%.All 169 inv(9)-eligibledonors were contacted to collect fertility outcome data,along with 206 eligible donors without inv(9)as controls.In addition,semen samples from inv(9)-eligible donors and eligible donors underwent assessments of sperm fluorescence in situ hybridization(FISH),mitochondrial membrane potential,DNA fragmentation index,acrosome integrity,reactive oxygen species(ROS),andsperm morphology.Results showed that inv(9)did not significantly increase reproductive risks overall.Despite detecting ROSlevel differences,the clinical impact may be insignificant.This study provides new data on the inv(9)population that can serveas a valuable reference for decision-making by sperm banks as well as for genetic counseling and clinical guidance for individualscarrying inv(9)variant.展开更多
BACKGROUND The research findings suggest that the prognosis of children with Wilms tumor(WT)is affected by various factors.Some scholars have indicated that loss of heterozygosity(LOH)on chromosome 16q is associated w...BACKGROUND The research findings suggest that the prognosis of children with Wilms tumor(WT)is affected by various factors.Some scholars have indicated that loss of heterozygosity(LOH)on chromosome 16q is associated with a poor prognosis in patients with WT.AIM To further elucidate this relationship,we conducted a meta-analysis.METHODS This meta-analysis was registered in INPLASY(INPLASY2023100060).We systematically searched databases including Embase,PubMed,Web of Science,Cochrane,and Google Scholar up to May 31,2020,for randomized trials reporting any intrapartum fetal surveillance approach.The meta-analysis was performed within a frequentist framework,and the quality and network inconsistency of trials were assessed.Odds ratios and 95%CIs were calculated to report the relationship between event-free survival and 16q LOH in patients with WT.RESULTS Eleven cohort studies were included in this meta-analysis to estimate the relationship between event-free survival and 16q LOH in patients with WT(I^(2)=25%,P<0.001).As expected,16q LOH can serve as an effective predictor of eventfree survival in patients with WT(risk ratio=1.95,95%CI:1.52–2.49,P<0.001).CONCLUSION In pediatric patients with WT,there exists a partial correlation between 16q LOH and an unfavorable treatment prognosis.Clinical detection of 16q chromosome LOH warrants increased attention to the patient’s prognosis.展开更多
Wheat cultivar Zhongmai 895 was earlier found to carry YR86 in an 11.6 Mb recombination-suppressed region on chromosome 2AL when crossed with Yangmai 16.To fine-map the YR86 locus,we developed two large F2 populations...Wheat cultivar Zhongmai 895 was earlier found to carry YR86 in an 11.6 Mb recombination-suppressed region on chromosome 2AL when crossed with Yangmai 16.To fine-map the YR86 locus,we developed two large F2 populations from crosses Emai 580/Zhongmai 895 and Avocet S/Zhongmai 895.Remarkably,both populations exhibited suppressed recombination in the same 2AL region.Collinearity analysis across Chinese Spring,Aikang 58,and 10+wheat genomes revealed a 4.1 Mb chromosomal inversion spanning 708.5-712.6 Mb in the Chinese Spring reference genome.Molecular markers were developed in the breakpoint and were used to assess a wheat cultivar panel,revealing that Chinese Spring,Zhongmai 895,and Jimai 22 shared a common sequence named InvCS,whereas Aikang 58,Yangmai 16,Emai 580,and Avocet S shared the sequence named InvAK58.The inverted configuration explained the suppressed recombination observed in all three bi-parental populations.Normal recombination was observed in a Jimai 22/Zhongmai 895 F2 population,facilitating mapping of YR86 to a genetic interval of 0.15 cM corresponding to 710.27-712.56 Mb falling within the inverted region.Thirty-three high-confidence genes were annotated in the interval using the Chinese Spring reference genome,with six identified as potential candidates for YR86 based on genome and transcriptome analyses.These results will accelerate map-based cloning of YR86 and its deployment in wheat breeding.展开更多
Lung cancer is a leading cause of cancer death worldwide. Some lung cancer patients correlate with a gas of radon besides smoking. To search for common chromosomal aberrations in lung cancer cell lines established fro...Lung cancer is a leading cause of cancer death worldwide. Some lung cancer patients correlate with a gas of radon besides smoking. To search for common chromosomal aberrations in lung cancer cell lines established from patients induced by different factors, a combined approach of chromosome sorting, forward and reverse chromosome painting was used to characterize karyotypes of two lung adenocarcinoma cell lines： A549 and GLC-82 with the latter line derived from a patient who has suffered long-term exposure to environmental radon gas pollution. The chromosome painting results revealed that complex chromosomal rearrangements occurred in these two lung adenocarcinoma cell lines. Thirteen and twenty-four abnormal chromosomes were identified An A549 and GLC-82 cell lines, respectively. Almost half of abnormal chromosomes in these two cell lines were formed by non-reciprocal translocations, the others were derived from deletions and duplication/or amplification in some chromosomal regions. Furthermore, two apparently common breakpoints, HSA8q24 and 12q14 were found in these two lung cancer cell lines.展开更多
Chromosome malsegregation in binucleated lymphocytes is a useful endpoint to evaluate age effect on genetic stability. However, the investigations on chromosome malsegregation in binucleated lymphocytes from Chinese a...Chromosome malsegregation in binucleated lymphocytes is a useful endpoint to evaluate age effect on genetic stability. However, the investigations on chromosome malsegregation in binucleated lymphocytes from Chinese are scarce. In this study, peripheral blood lym- phocytes were collected from 14 old （60-70 years） and 10 young （22-26 years） healthy Chinese men. To detect malsegregation of the sex chromosomes, multi-color fluorescence in situ hybridization （FISH） was performed on binucleated lymphocytes, cytokinesis-blocked by cytochalasin B at the first mitosis after phytohaemagglutinin stimulation. Compared with that in young men, a significant increase in frequencies of loss of chromosome X （9.2± 3.2‰ vs. 1.1 ± 0.9‰, P 〈 0.001） and Y （2.5 ± 1.9‰ vs. 0.2± 0.3‰, P 〈 0.001） was found in old men. Similarly, nondisjunction of chromosome X （16.5± 3.4‰ vs. 3.5 ± 1.1‰, P 〈 0.001） and Y （7.2 ± 2.6‰ vs. 2.4 ± 1.3‰, P 〈 0.001） occurred more frequently in old men than in young men. Regardless of donor＇s age, nondisjunction is more prevalent than loss for both chromosome X and Y. The frequencies of observed simultaneous malsegregation were relatively higher than the expected, suggest- ing an association between malsegregation. These results indicated that in Chinese men, malsegregation of the sex chromosomes increases with age in an associated fashion, and nondisjunction accounts for the majority of spontaneous chromosome malsegregation.展开更多
Using foxtail millet (Setaria italica (L.) Beauv.) male-sterile line 1066A as female parent and Yugu 1 primary trisomic series (1 - 7) and tetrasomics 8, 9 as male parents, chromosome location of gene for male-sterili...Using foxtail millet (Setaria italica (L.) Beauv.) male-sterile line 1066A as female parent and Yugu 1 primary trisomic series (1 - 7) and tetrasomics 8, 9 as male parents, chromosome location of gene for male-sterility and yellow seedling in line 1066A was studied by primary trisomic analysis. The plants of F-1 generation of trisomics 2 - 9 were obtained by crossing with a great many plants of 1066A. F-1 generation of trisomics was similar to their male parent in morphologic characters, the color of their seedling was green, and pollen was partially fertile. The segregation ratio of fertility to sterility is 3:1 in F-2 generation of trisomics 2, 3, 4, 5, 7, 8 and 9; and 14:1 only in F-2 generation of trisomic 6 (chi(0.05)(2) = 0.012). The segregation ratio of green seedling to yellow seedling is 12:1 only in F-2 generation of trisomic 7 (chi(0.05)(2) = 0.31), but in other cases, this ratio is 3:1. The results indicated that the male-sterility gene was located on chromosome 6, and the gene for yellow seedling was monogenic recessive and located on chromosome 7. The rate of trisomics transmission by pollen was tested, trisomics 8 and 9 were the highest in rates of trisomics transmission and followed by trisomics 6 and 4.展开更多
Comparing to its sister-family （Rhinolophidae）, Hipposideridae was less studied by cytogenetic approaches. Only a few high-resolution G-banded karyotypes have been reported so far, and most of the conclusions on the...Comparing to its sister-family （Rhinolophidae）, Hipposideridae was less studied by cytogenetic approaches. Only a few high-resolution G-banded karyotypes have been reported so far, and most of the conclusions on the karyotypic evolution in Hipposideridae were based on conventional Giemsa-staining. In this study, we applied comparative chromosome painting, a method of choice for genome-wide comparison at the molecular level, and G- and C-banding to establish comparative map between five hipposiderid species from China, using a whole set of chromosome-specific painting probes from one of them （Aselliscus stoliczkanus）. G-band and C-band comparisons between homologous segments defined by chromosome painting revealed that Robertsonian translocations, paracentric inversions and heterochromatin addition could be the main mechanism of chromosome evolution in Hipposideridae. Comparative analysis of the conserved chromosomal segments among five hipposiderid species and outgroup species suggests that bi-armed chromosomes should be included into the ancestral karyotype of Hipposideridae, which was previously believed to be exclusively composed of acrocentric chromosomes.展开更多
Amphioxus has an important evolutionary position as a result of their phylogenetic position relative to vertebrates. Understanding their chromosomes would provide key points in the study of evolutionary biology and co...Amphioxus has an important evolutionary position as a result of their phylogenetic position relative to vertebrates. Understanding their chromosomes would provide key points in the study of evolutionary biology and comparative genomics. The difficulty in preparing amphioxus chromosomes currently provides a significant hurdle in this research. In the current study, we describe an improved method for metaphase preparation from amphioxus embryos and methodology for preparing metaphase spreads from regenerative somatic cells. Chromosomes of two amphioxus species from Xiamen waters in China are also observed. The diploid chromosome number was found to be 40 in Branchiostoma belcheri, while B. japonicum has 36, confirming the two are distinct species from cytotaxonomic viewpoint.展开更多
Gossypium hirsutum L. and G. barbadense L. are the two cultivated tetraploid species of cotton. The first is characterized by a high yield and wide adaptation, and the second by its super fiber property. Substit...Gossypium hirsutum L. and G. barbadense L. are the two cultivated tetraploid species of cotton. The first is characterized by a high yield and wide adaptation, and the second by its super fiber property. Substitution line in which a pair of intact chromosomes of TM_1 ( G. hirsutum ) were replaced by a pair of homozygous chromosomes of 3_79 ( G. barbadense ) is an excellent material for genetic research and molecular tagging. In this study, substitution line 16 (Sub 16) was used to evaluate the performance of the 16th chromosome in G. barbadense in TM_1 background. The genetic analysis using the major gene plus polygene mixed inheritance model in F 2∶3 family revealed that there might exist 2 QTLs respectively for boll size, lint percentage, lint index, fiber length and the first fruit branch node, 1 QTL for fiber elongation and flowering date, and no QTL for seed index, fiber strength and Micronaire in chromosome 16. However, 9 QTLs (LOD (logarithm of odds)≥3.0) controlling 6 quantitative traits were significantly identified in linkage group of chromosome 16 constructed in (TM_1×3_79) F 2by interval mapping. Among them, 1 QTL for boll size, fiber length, flowering date and fiber elongation could explain 15.2%, 19.7%, 12.1%, and 11.7% phenotypic variance respectively, 2 QTLs for lint index could explain 11.6% and 41.9%, and 3 QTLs for lint percentage could explain 8.7%, 9.6% and 29.2% phenotypic variance respectively. One unlinked SSR marker was associated with one QTL respectively for boll size and flowering date and they could explain 1.60% and 4.63% phenotypic variance. The traits associated significantly with chromosome 16 from Sub 16 were boll weight, lint percentage, lint index, fiber length, fiber elongation and flowering days.展开更多
文摘The stability and evolution of human genetics depend on chromosomes and chromosome-chromosome interactions.We wish to understand the spatial location of chromosomes in dividing cells in order to understand the relationship between chromosome-chromosome interactions and to further investigate the role of chromosomes and their impact on cell biological behavior.In this study,we explored the relative spatial positional relationships of chromosomes[t(9;22)and t(15;17)]in B-ALL cells by using the three-dimensional DNA fluorescent in situ hybridization(3D-FISH)method.The results showed that chromosomes[t(9;22)and t(15;17)]showed relatively stable spatial relationships.The relative stability of the spatial location of chromosomes in dividing cells may be relevant to disease.
文摘Purpose:Derivative chromosomes,resulting from complex structural rearrangements,pose significant challenges in prenatal diagnosis due to their unpredictable inheritance patterns and potential phenotypic consequences.This study evaluates the efficacy of multiple genetic technologies-including karyotyping,fluorescence in situ hybridization(FISH),chromosomal microarray analysis(CMA),and next-generation sequencing(NGS)-in detecting and characterizing derivative chromosomes in prenatal samples.methodology:We analyzed 150 cases of suspected chromosomal abnormalities,comparing detection rates,resolution,and clinical utility across these methods.Results:Our findings demonstrate that integrated multi-technology approaches significantly improve diagnostic accuracy,with NGS-based structural variation analysis achieving the highest detection sensitivity(99.2%)for cryptic rearrangements.Conclusions:Additionally,long-read sequencing(PacBio/Oxford Nanopore)enabled precise breakpoint mapping in 92%of cases,facilitating more accurate genetic counseling.Clinically,this approach enhances risk assessment for fetal anomalies,guides pregnancy management,and improves parental counseling for recurrence risks.
基金supported by the National Natural Science Foundation of China(Nos.52091545 and 51978645).
文摘The objective of this study is to quantitatively reveal the main genetic carrier of antibiotic resistance genes(ARGs)for blocking their environmental dissemination.The distribution of ARGs in chromosomes,plasmids,and phages for understanding their respective contributions to the development of antimicrobial resistance in aerobic biofilm consortium under increasing stresses of oxytetracycline,streptomycin,and tigecyclinewere revealed based on metagenomics analysis.Results showed that the plasmids harbored 49.2%-83.9%of resistomes,which was higher(p<0.001)than chromosomes(2.0%-35.6%),and no ARGs were detected in phage contigs under the strict alignment standard of over 80%identity used in this study.Plasmids and chromosomes tended to encode different types of ARGs,whose abundances all increased with the hike of antibiotic concentrations,and the variety of ARGs encoded by plasmids(14 types and 64 subtypes)was higher than that(11 types and 27 subtypes)of chromosomes.The dosing of the three antibiotics facilitated the transposition and recombination of ARGs on plasmids,mediated by transposable and integrable transfer elements,which increased the co-occurrence of associated and unassociated ARGs.The results quantitatively proved that plasmids dominate the proliferation of ARGs in aerobic biofilm driven by antibiotic selection,which should be a key target for blocking ARG dissemination.
基金Supported by the National Natural Science Foundation of China,No.82002940 and No.82203336Shaanxi Natural Science Foundation,No.2023-JC-YB-166.
文摘BACKGROUND Hepatocellular carcinoma(HCC)ranks among the most prevalent and deadly malignancies,characterized by a high recurrence rate.Regulator of chromosome condensation 1(RCC1)serves as a principal guanine nucleotide exchange factor for ras-related nuclear protein guanosine triphosphatase(GTPase)and is implicated in various cancers.However,the role of RCC1 in HCC remains unex-plored.AIM To elucidate the functional significance and molecular mechanisms of RCC1 in HCC.METHODS Bioinformatics were to examine the expression levels of RCC1 in HCC and to assess its impact on the prognosis of this malignancy.The cell counting kit-8 assay and flow cytometry were utilized to evaluate the cell viability and cell cycle of HCC cells.Furthermore,quantitative reverse transcription and immunoblotting were to investigate the influence of RCC1 on cyclin associated proteins.RESULTS Bioinformatics analysis revealed that RCC1 was highly expressed in HCC and correlated with poor prognosis in HCC patients.Functional studies showed that RCC1 overexpression promoted the malignant phenotype of HCC cells,especially the proliferation of HCC cells,whereas RCC1 knockdown had the opposite effect.Mechanistically,we identied cell division cycle-associated(CDCA)8 as a downstream target of RCC1 in HCC.RCC1 overexpression markedly increased CDCA8 levels,consequently enhancing cell proliferation and survival in HCC cells.Additionally,we discovered that RCC1 contributed to the development and progression of HCC by activating the phosphoinositide 3-kinase/protein kinase B/cyclin-dependent kinase inhibitor 1a pathway through CDCA8.CONCLUSION Our study provides profound insights into the pivotal role of RCC1 in HCC and its potential as a therapeutic target.
基金supported by Science and Technology Innovation 2030-Major Project (2023ZD04025)the Fundamental Research Funds for the Central Universities (XUEKEN2022012,YDZX202301)+3 种基金Zhongshan Biological Breeding Laboratory (ZSBBL)ZSBBL-KY2023-02-2,Jiangsu Provincial Key Research and Development Program (BE2022346,BE2021375)Seed Industry Revitalization Project of Jiangsu Province (JBGS (2021)006,JBGS (2021)013 and JBGS (2021)047)the Joint Research of Improved Wheat Variety of Anhui,the Key Research and the Jiangsu Agricultural Technology System (JATS) ([2023]422)Natural Science Foundation of Shanghai (22ZR1444900).
文摘Fusarium head blight(FHB)threatens wheat production worldwide.Utilization of FHB resistant varieties is the most effective solution for disease control.Owing to the limited sources of FHB resistance,mining of novel resistance genes is crucial.Here,we report an FHB resistance gene from a wild wheat relative species,Roegneria ciliaris and developed FHB resistant germplasm containing this gene.Wheat-R.ciliaris disomic addition line DA3S^(c) showed enhanced type II FHB resistance compared to its sister line 3S^(c)-Null without chromosome 3S^(c),indicating that the resistance was contributed by the addition of 3S^(c).The resistance gene on 3S^(c) was validated using F_(2) and F_(2:3) populations derived from the cross between DA3S^(c) and susceptible Aikang 58(a susceptible cultivar),demonstrating that the lines with 3S^(c) had significantly enhanced FHB resistance compared to the individuals without 3S^(c).This was the second resistance gene identified in R.ciliaris,designated FhbRc2.To transfer FhbRc2 to common wheat,we produced a doublemonosomic chromosome population by crossing DA3S^(c) with the Chinese Spring nulli-tetrasomic line N3DT3B.Eight alien chromosome lines containing 3S^(c) were identified using genomic/fluorescence in situ hybridization and 3S^(c)-specific marker analysis.Only the lines carrying the long arm of 3S^(c) conferred FHB resistance,further locating FhbRc2 on 3S^(c)L.A compensating wheat-R.ciliaris Robertsonian translocation line T3DS·3S^(c)L harboring FhbRc2 is developed and provides a potential genetic resource in wheat breeding for enhanced FHB resistance.
基金funded by the Central Government and Local Science and Technology Development Special Project,China(2022L3086)the Sugarcane Research Foundation of Guangxi University,China(2022GZB006)+3 种基金supported by the National Natural Science Foundation of China(31771863)the Academy of Sugarcane and Sugar Industry,Guangxi University,China(ASSI-2023009)an independent fund of Guangxi Key Laboratory of Sugarcane Biology,China(GXKLSCB-20190201)the China Agriculture Research System of MOF and MARA(CARS-20-1-5)。
文摘Sugarcane has recently attracted increasing attention for its potential as a source of sugar and bioethanol,so increasing its yield is essential to ensure the sugar security and bioenergy production.Intergeneric hybridization is a highly efficient method to produce new genetic variants of crop plants,particularly those species with high ploidy such as sugarcane(Saccharum spp.).Tripidium arundinaceum exhibits many desirable agronomic traits,and has been widely studied to produce hybrids with improved stress tolerance and other characteristics in sugarcane breeding.However,the genetic relationship between T.arundinaceum and Saccharum species,and the individual T.arundinaceum chromosomal compositions in sugarcane hybrids are still elusive.Here we used whole-genome single-nucleotide polymorphisms(SNPs)to ascertain the phylogenetic relationships between these species and found that T.arundinaceum is more closely related to Saccharum than Sorghum,in contrast to the previous narrow genetic analyses using chloroplast DNA.Additionally,oligonucleotide(oligo)-based chromosome-specific painting derived from Saccharum officinarum was able to distinctly identify the chromosomes of T.arundinaceum.We developed the oligo-genomic in situ hybridization(GISH)system for the first time,to unveil the novel chromosome translocations and the transmission of individual T.arundinaceum chromosomes in sugarcane progeny.Notably,we discovered that the chromosomal transmission of T.arundinaceum exhibited several different inheritance modes,including n,2n,and over 2n in the BC1 progenies.Such inheritance patterns may have resulted from first division restitution(FDR)or FDR+nondisjunction of a chromosome with the sister chromatids in the second meiosis division/second division restitution(FDR+NSC/SDR)model during meiosis.These results will be of substantial benefit for the further selection of T.arundinaceum chromosomes for sugarcane genetic improvement.
基金supported by the Shenzhen Science and Technology Program,China(No.KQTD20190929172749226).
文摘Meiosis is the process of producing haploid gametes through a series of complex chromosomal events and the coordinated action of various proteins.The mitochondrial protease complex(ClpXP),which consists of caseinolytic mitochondrial matrix peptidase X(ClpX)and caseinolytic protease P(ClpP)and mediates the degradation of misfolded,damaged,and oxidized proteins,is essential for maintaining mitochondrial homeostasis.ClpXP has been implicated in meiosis regulation,but its precise role is currently unknown.In this study,we engineered an inducible male germ cell-specific knockout caseinolytic mitochondrial matrix peptidase X(Clpx^(cKO))mouse model to investigate the function of ClpX in meiosis.We found that disrupting Clpx in male mice induced germ cell apoptosis and led to an absence of sperm in the epididymis.Specifically,it caused asynapsis of homologous chromosomes and impaired meiotic recombination,resulting in meiotic arrest in the zygotene-to-pachytene transition phase.The loss of ClpX compromised the double-strand break(DSB)repair machinery by markedly reducing the recruitment of DNA repair protein RAD51 homolog 1(RAD51)to DSB sites.This dysfunction may be due to an insufficient supply of energy from the aberrant mitochondria in Clpx^(cKO) spermatocytes,as discerned by electron microscopy.Furthermore,ubiquitination signals on chromosomes and the expression of oxidative phosphorylation subunits were both significantly attenuated in Clpx^(cKO) spermatocytes.Taken together,we propose that ClpX is essential for maintaining mitochondrial protein homeostasis and ensuring homologous chromosome pairing,synapsis,and recombination in spermatocytes during meiotic prophase I.
基金supported by the National Natural Science Foundation of China(31861123001,31630082,and 32172953)National Key Research and Development Program of China(2022YFD1201600)+2 种基金Chongqing Fishery Technology Innovation Union(CQFTIU2024-08)the Science Foundation of School of Life Sciences SWU(20232005276101)the US National Science Foundation(DEB#1830753)。
文摘The impact of sex chromosomes and their turnover in speciation remains a subject of ongoing debate in the field of evolutionary biology.Fishes are the largest group of vertebrates,and they exhibit unparalleled sexual plasticity,as well as diverse sex-determining(SD)genes,sex chromosomes,and sex-determination mechanisms.This diversity is hypothesized to be associated with the frequent turnover of sex chromosomes in fishes.Although it is evident that amh and amhr2 are repeatedly and independently recruited as SD genes,their relationship with the rapid turnover of sex chromosomes and the biodiversity of fishes remains unknown.We summarize the canonical models of sex chromosome turnover and highlight the vital roles of gene mutation and hybridization with empirical evidence.We revisit Haldane’s rule and the large Xeffect and propose the hypothesis that sex chromosomes accelerate speciation by multiplying genotypes via hybridization.By integrating recent findings on the turnover of SD genes,sex chromosomes,and sexdetermination systems in fish species,this review provides insights into the relationship between sex chromosome evolution and biodiversity in fishes.
基金supported by the Science and Technology Innovation 2030-Major Project (2023ZD0403001)China Agriculture Research System (CARS-02)+3 种基金Beijing Academy of Agriculture and Forestry Sciences Excellent Scientist Training Program (JKZX202202)National Natural Science Foundation of China (32001554)Beijing Academy of Agriculture and Forestry Sciences Science and Technology Innovation Capability Improvement Project (KJCX20230103)Chinese Universities Scientific Fund (2022TC141).
文摘Doubled haploid(DH)technology is an efficient method used in commercial maize breeding.Chromosome doubling is a vital step of DH technology;however,the underlying processes regulating chromosome doubling of haploid is still not well understood,which is key to optimize the technology.In this study,the immature haploid embryos of the maize inbred line Zheng58 treated with amiprophos-methyl(APM)or colchicine were used to analyze transcriptomic and metabolomic changes,75 and 60 differential expressed metabolites(DEMs)were identified between control treatment,respectively.Most differentially expressed genes(DEGs)related to artificial chromosome doubling were down regulated;these were mainly involved in mitosis process.Both DEMs and DEGs co-expression analyses showed that,compared to controls,zeatin biosynthesis and cofactor and vitamin metabolism were significantly enriched in both APM and colchicine treatments.In a parallel experiment,exogenous vitamins including thiamine,nicotinic acid,vitamin B6,or trans-zeatin were added to colchicine treatment;there were synergistic effects between vitamins or zeatin and colchicine in haploid artificial chromosome doubling.These results provide novel insights in exploring the molecular responses to antimitotic reagents at both the transcriptomic and metabolomic levels.In addition,the application efficiency of haploid breeding will be greatly improved by the key factors for artificial chromosome doubling.
基金supported by the National Natural Science Foundation of China(32172503 and 32260721)the Natural Science Foundation of Fujian Province,China(2023J01069)+2 种基金the State Key Laboratory of Ecological Pest Control for Fujian and Taiwan Crops,China(SKL2022001)the Innovation Fund of Fujan Agriculture and Forestry University,China(KFB23014A)the Undergraduate Training Program for Innovation and Entrepreneurship of Fujian Province,China(S202210389101).
文摘Genetic pest control strategies based on precise sex separation and only releasing sterile males can be accomplished by site-specific genome editing.In the current study,we showed that the mutation of single-allele Pxfl(2)d can significantly impair the normal mating behavior and testis development in male adults of the notorious cruciferous insect pest Plutella xylostella,in addition to its known functions in the ovarian development in female adults and egg hatching.Subsequent CRISPR/Cas9-based knock-in experiments revealed that site-specific integration of an exogenous green fluorescent protein(GFP)gene into autosomal Pxfl(2)d for labelling mutants could be achieved.However,this gene is not a suitable target for GFP insertion to establish a genetically stable knock-in strain because of the severe decline in reproductive capacity.We further screened for the W-chromosome-linked and Z-chromosome-linked regions to test the knock-in efficiency mediated by CRISPR/Cas9.The results verified that both types of chromosomes can be targeted for the site-specific insertion of exogenous sequences.We ultimately obtained a homozygous knock-in strain with the integration of both Cas9 and cyan fluorescent protein(CFP)expression cassettes on a Z-linked region in P.xylostella,which can also be used for early sex detection.By injecting the sgRNA targeting Pxfl(2)d alone into the eggs laid by female adults of the Z-Cas9-CFP strain,the gene editing efficiency reached 29.73%,confirming the success of expressing a functional Cas9 gene.Taken together,we demonstrated the feasibility of the knock-in of an exogenous gene to different genomic regions in P.xylostella,while the establishment of a heritable strain required the positioning of appropriate sites.This study provides an important working basis and technical support for further developing genetic strategies for insect pest control.
基金supported by the National Key Research and Development Program of China(2022YFD2400100)National Natural Science Foundation of Shandong Province of China(ZR2023QC006)National Natural Science Foundation of China(32403053)。
文摘The identification of sex chromosomes is fundamental for exploring the mechanism and evolution of sex determination.Platichthys stellatus,a species exhibiting clear sexual dimorphism and homomorphic chromosome pairs,has received limited research concerning its sex determination mechanisms.Clarifying the sex chromosome of P.stellatus will enhance our understanding of sex chromosome evolution in Pleuronectiformes.This study employed whole-genome resequencing to investigate the sex chromosome and sex determination system in P.stellatus.Notably,Chr23 was identified as the sex chromosome in P.stellatus,with the sex-determining region(SDR)occupying 48.1%of the chromosome and featuring an XX/XY system.Sex chromosome turnover was observed within Pleuronectiformes,with P.stellatus,Verasper variegatus,and Hippoglossus hippoglossus sharing a common ancestral karyotype.No inversions were detected within the SDR of P.stellatus,although chromosomal rearrangements between sex chromosomes and autosomes were identified.Additionally,a sex-specific marker for P.stellatus was ascertained,enabling genetic sex identification,with significant implications for improving breeding programs and aquaculture practices.
基金financial supported by National Natural Science Foundationof China(No.82001634)the China Postdoctoral Science Foundation(No.2019M661521).
文摘Pericentric inversion of chromosome 9(inv[9])is a common chromosomal structural variant,but its impact on clinical outcomesremains debated.The screening criteria of sperm banks are rarely mentioned to individuals with inv(9).In this study,we evaluatedthe fertility of sperm donors with inv(9)who met eligibility criteria for sperm banks(inv[9]-eligible donors).From March 2004 toMay 2022,chromosomal analysis of 16124 sperm donors at CITIC-Xiangya Human Sperm Bank in Hunan Province(Changsha,China)found that 251(1.6%)had chromosome variations,with inv(9)being the most prevalent at 1.1%.All 169 inv(9)-eligibledonors were contacted to collect fertility outcome data,along with 206 eligible donors without inv(9)as controls.In addition,semen samples from inv(9)-eligible donors and eligible donors underwent assessments of sperm fluorescence in situ hybridization(FISH),mitochondrial membrane potential,DNA fragmentation index,acrosome integrity,reactive oxygen species(ROS),andsperm morphology.Results showed that inv(9)did not significantly increase reproductive risks overall.Despite detecting ROSlevel differences,the clinical impact may be insignificant.This study provides new data on the inv(9)population that can serveas a valuable reference for decision-making by sperm banks as well as for genetic counseling and clinical guidance for individualscarrying inv(9)variant.
基金Supported by Yunnan Provincial Department of Science and Technology Provincial Basic Research Program(Kunming Medical Joint Special Project,No.2019FE001(-276)Kunming Health Science and Technology Talents Training Project and"Ten Hundred Thousands"Project Training Plan,No.2020-SW(Backup)-121.
文摘BACKGROUND The research findings suggest that the prognosis of children with Wilms tumor(WT)is affected by various factors.Some scholars have indicated that loss of heterozygosity(LOH)on chromosome 16q is associated with a poor prognosis in patients with WT.AIM To further elucidate this relationship,we conducted a meta-analysis.METHODS This meta-analysis was registered in INPLASY(INPLASY2023100060).We systematically searched databases including Embase,PubMed,Web of Science,Cochrane,and Google Scholar up to May 31,2020,for randomized trials reporting any intrapartum fetal surveillance approach.The meta-analysis was performed within a frequentist framework,and the quality and network inconsistency of trials were assessed.Odds ratios and 95%CIs were calculated to report the relationship between event-free survival and 16q LOH in patients with WT.RESULTS Eleven cohort studies were included in this meta-analysis to estimate the relationship between event-free survival and 16q LOH in patients with WT(I^(2)=25%,P<0.001).As expected,16q LOH can serve as an effective predictor of eventfree survival in patients with WT(risk ratio=1.95,95%CI:1.52–2.49,P<0.001).CONCLUSION In pediatric patients with WT,there exists a partial correlation between 16q LOH and an unfavorable treatment prognosis.Clinical detection of 16q chromosome LOH warrants increased attention to the patient’s prognosis.
基金financially supported by the National Key Research and Development Program of China (2022YFD1200900 and 2022YFD1200904)the Agricultural Science and Technology Innovation Program+1 种基金Fundamental Research Funds for Central NonProfit of Institute of Crop Sciences, CAASShijiazhuang S&T Project (232490022A and 232490432A)
文摘Wheat cultivar Zhongmai 895 was earlier found to carry YR86 in an 11.6 Mb recombination-suppressed region on chromosome 2AL when crossed with Yangmai 16.To fine-map the YR86 locus,we developed two large F2 populations from crosses Emai 580/Zhongmai 895 and Avocet S/Zhongmai 895.Remarkably,both populations exhibited suppressed recombination in the same 2AL region.Collinearity analysis across Chinese Spring,Aikang 58,and 10+wheat genomes revealed a 4.1 Mb chromosomal inversion spanning 708.5-712.6 Mb in the Chinese Spring reference genome.Molecular markers were developed in the breakpoint and were used to assess a wheat cultivar panel,revealing that Chinese Spring,Zhongmai 895,and Jimai 22 shared a common sequence named InvCS,whereas Aikang 58,Yangmai 16,Emai 580,and Avocet S shared the sequence named InvAK58.The inverted configuration explained the suppressed recombination observed in all three bi-parental populations.Normal recombination was observed in a Jimai 22/Zhongmai 895 F2 population,facilitating mapping of YR86 to a genetic interval of 0.15 cM corresponding to 710.27-712.56 Mb falling within the inverted region.Thirty-three high-confidence genes were annotated in the interval using the Chinese Spring reference genome,with six identified as potential candidates for YR86 based on genome and transcriptome analyses.These results will accelerate map-based cloning of YR86 and its deployment in wheat breeding.
基金supported partly by grants from the Ministry of Science and Technology of China(2005DKA21502)the Joint Foundation of Science and Technology Bureau of Yunnan Province and Kunming Medical University(2007C0024R)
文摘Lung cancer is a leading cause of cancer death worldwide. Some lung cancer patients correlate with a gas of radon besides smoking. To search for common chromosomal aberrations in lung cancer cell lines established from patients induced by different factors, a combined approach of chromosome sorting, forward and reverse chromosome painting was used to characterize karyotypes of two lung adenocarcinoma cell lines： A549 and GLC-82 with the latter line derived from a patient who has suffered long-term exposure to environmental radon gas pollution. The chromosome painting results revealed that complex chromosomal rearrangements occurred in these two lung adenocarcinoma cell lines. Thirteen and twenty-four abnormal chromosomes were identified An A549 and GLC-82 cell lines, respectively. Almost half of abnormal chromosomes in these two cell lines were formed by non-reciprocal translocations, the others were derived from deletions and duplication/or amplification in some chromosomal regions. Furthermore, two apparently common breakpoints, HSA8q24 and 12q14 were found in these two lung cancer cell lines.
基金supported by the National Natural Science Foundation of China (No.30571030,30671168 and 30725013)the Program of "One Hundred Talented People" (No.KJ207004) of the Chinese Academy of Sciences
文摘Chromosome malsegregation in binucleated lymphocytes is a useful endpoint to evaluate age effect on genetic stability. However, the investigations on chromosome malsegregation in binucleated lymphocytes from Chinese are scarce. In this study, peripheral blood lym- phocytes were collected from 14 old （60-70 years） and 10 young （22-26 years） healthy Chinese men. To detect malsegregation of the sex chromosomes, multi-color fluorescence in situ hybridization （FISH） was performed on binucleated lymphocytes, cytokinesis-blocked by cytochalasin B at the first mitosis after phytohaemagglutinin stimulation. Compared with that in young men, a significant increase in frequencies of loss of chromosome X （9.2± 3.2‰ vs. 1.1 ± 0.9‰, P 〈 0.001） and Y （2.5 ± 1.9‰ vs. 0.2± 0.3‰, P 〈 0.001） was found in old men. Similarly, nondisjunction of chromosome X （16.5± 3.4‰ vs. 3.5 ± 1.1‰, P 〈 0.001） and Y （7.2 ± 2.6‰ vs. 2.4 ± 1.3‰, P 〈 0.001） occurred more frequently in old men than in young men. Regardless of donor＇s age, nondisjunction is more prevalent than loss for both chromosome X and Y. The frequencies of observed simultaneous malsegregation were relatively higher than the expected, suggest- ing an association between malsegregation. These results indicated that in Chinese men, malsegregation of the sex chromosomes increases with age in an associated fashion, and nondisjunction accounts for the majority of spontaneous chromosome malsegregation.
文摘Using foxtail millet (Setaria italica (L.) Beauv.) male-sterile line 1066A as female parent and Yugu 1 primary trisomic series (1 - 7) and tetrasomics 8, 9 as male parents, chromosome location of gene for male-sterility and yellow seedling in line 1066A was studied by primary trisomic analysis. The plants of F-1 generation of trisomics 2 - 9 were obtained by crossing with a great many plants of 1066A. F-1 generation of trisomics was similar to their male parent in morphologic characters, the color of their seedling was green, and pollen was partially fertile. The segregation ratio of fertility to sterility is 3:1 in F-2 generation of trisomics 2, 3, 4, 5, 7, 8 and 9; and 14:1 only in F-2 generation of trisomic 6 (chi(0.05)(2) = 0.012). The segregation ratio of green seedling to yellow seedling is 12:1 only in F-2 generation of trisomic 7 (chi(0.05)(2) = 0.31), but in other cases, this ratio is 3:1. The results indicated that the male-sterility gene was located on chromosome 6, and the gene for yellow seedling was monogenic recessive and located on chromosome 7. The rate of trisomics transmission by pollen was tested, trisomics 8 and 9 were the highest in rates of trisomics transmission and followed by trisomics 6 and 4.
基金supported by grants from the National Natural Science Foundation of China(30770293)the Ministry of Science and Technology of China(2005DKA21502)
文摘Comparing to its sister-family （Rhinolophidae）, Hipposideridae was less studied by cytogenetic approaches. Only a few high-resolution G-banded karyotypes have been reported so far, and most of the conclusions on the karyotypic evolution in Hipposideridae were based on conventional Giemsa-staining. In this study, we applied comparative chromosome painting, a method of choice for genome-wide comparison at the molecular level, and G- and C-banding to establish comparative map between five hipposiderid species from China, using a whole set of chromosome-specific painting probes from one of them （Aselliscus stoliczkanus）. G-band and C-band comparisons between homologous segments defined by chromosome painting revealed that Robertsonian translocations, paracentric inversions and heterochromatin addition could be the main mechanism of chromosome evolution in Hipposideridae. Comparative analysis of the conserved chromosomal segments among five hipposiderid species and outgroup species suggests that bi-armed chromosomes should be included into the ancestral karyotype of Hipposideridae, which was previously believed to be exclusively composed of acrocentric chromosomes.
基金Supported by grants from NSFC (No.30570208)SRFDP of Ministry of Education, China (20070384041)The Education Department of Fujian Province, China (JB07063)
文摘Amphioxus has an important evolutionary position as a result of their phylogenetic position relative to vertebrates. Understanding their chromosomes would provide key points in the study of evolutionary biology and comparative genomics. The difficulty in preparing amphioxus chromosomes currently provides a significant hurdle in this research. In the current study, we describe an improved method for metaphase preparation from amphioxus embryos and methodology for preparing metaphase spreads from regenerative somatic cells. Chromosomes of two amphioxus species from Xiamen waters in China are also observed. The diploid chromosome number was found to be 40 in Branchiostoma belcheri, while B. japonicum has 36, confirming the two are distinct species from cytotaxonomic viewpoint.
文摘Gossypium hirsutum L. and G. barbadense L. are the two cultivated tetraploid species of cotton. The first is characterized by a high yield and wide adaptation, and the second by its super fiber property. Substitution line in which a pair of intact chromosomes of TM_1 ( G. hirsutum ) were replaced by a pair of homozygous chromosomes of 3_79 ( G. barbadense ) is an excellent material for genetic research and molecular tagging. In this study, substitution line 16 (Sub 16) was used to evaluate the performance of the 16th chromosome in G. barbadense in TM_1 background. The genetic analysis using the major gene plus polygene mixed inheritance model in F 2∶3 family revealed that there might exist 2 QTLs respectively for boll size, lint percentage, lint index, fiber length and the first fruit branch node, 1 QTL for fiber elongation and flowering date, and no QTL for seed index, fiber strength and Micronaire in chromosome 16. However, 9 QTLs (LOD (logarithm of odds)≥3.0) controlling 6 quantitative traits were significantly identified in linkage group of chromosome 16 constructed in (TM_1×3_79) F 2by interval mapping. Among them, 1 QTL for boll size, fiber length, flowering date and fiber elongation could explain 15.2%, 19.7%, 12.1%, and 11.7% phenotypic variance respectively, 2 QTLs for lint index could explain 11.6% and 41.9%, and 3 QTLs for lint percentage could explain 8.7%, 9.6% and 29.2% phenotypic variance respectively. One unlinked SSR marker was associated with one QTL respectively for boll size and flowering date and they could explain 1.60% and 4.63% phenotypic variance. The traits associated significantly with chromosome 16 from Sub 16 were boll weight, lint percentage, lint index, fiber length, fiber elongation and flowering days.
