Dear Editor,Lung cancer is a major global health concern,with 2.2 million patients diagnosed in 2020.Non-small cell lung cancer(NSCLC)accounts for 80%of these cases,primarily comprising two subtypes:lung adenocarcinom...Dear Editor,Lung cancer is a major global health concern,with 2.2 million patients diagnosed in 2020.Non-small cell lung cancer(NSCLC)accounts for 80%of these cases,primarily comprising two subtypes:lung adenocarcinoma(LUAD)and squamous cell carcinoma(LUSC)[1].Researchers use immunohisto-chemistry,next-generation sequencing,and single-cell RNA sequencing to study genetic alterations,tumor heterogeneity,and tumor microenvironments,aiming to identify potential therapeutic options for specific NSCLC subtypes[2].展开更多
Chromosomal rearrangements(CRs)often cause phenotypic variations.Although several major rearrangements have been identified in Triticeae,a comprehensive study of the order,timing,and breakpoints of CRs has not been co...Chromosomal rearrangements(CRs)often cause phenotypic variations.Although several major rearrangements have been identified in Triticeae,a comprehensive study of the order,timing,and breakpoints of CRs has not been conducted.Here,we reconstruct high-quality ancestral genomes for the most recent common ancestor(MRCA)of the Triticeae,and the MRCA of the wheat lineage(Triticum and Aegilops).The protogenes of MRCA of the Triticeae and the wheat lineage are 22,894 and 29,060,respectively,which were arranged in their ancestral order.By partitioning modern Triticeae chromosomes into sets of syntenic regions and linking each to the corresponding protochromosomes,we revisit the rye chromosome structural evolution and propose alternative evolutionary routes.The previously identified 4L/5L reciprocal translocation in rye and Triticum urartu is found to have occurred independently and is unlikely to be the result of chromosomal introgression following distant hybridization.We also clarify that the 4AL/7BS translocation in tetraploid wheat was a bidirectional rather than unidirectional translocation event.Lastly,we identify several breakpoints in protochromosomes that independently reoccur following Triticeae evolution,representing potential CR hotspots.This study demonstrates that these reconstructed ancestral genomes can serve as special comparative references and facilitate a better understanding of the evolution of structural rearrangements in Triticeae.展开更多
Investigating the correlation between micronucleus formation and male infertility has the potential to improve clinical diagnosis and deepen our understanding of pathological progression. Our study enrolled 2252 male ...Investigating the correlation between micronucleus formation and male infertility has the potential to improve clinical diagnosis and deepen our understanding of pathological progression. Our study enrolled 2252 male patients whose semen was analyzed from March 2023 to July 2023. Their clinical data, including semen parameters and age, were also collected. Genetic analysis was used to determine whether the sex chromosome involved in male infertility was abnormal (including the increase, deletion, and translocation of the X and Y chromosomes), and subsequent semen analysis was conducted for clinical grouping purposes. The participants were categorized into five groups: normozoospermia, asthenozoospermia, oligozoospermia, oligoasthenozoospermia, and azoospermia. Patients were randomly selected for further study;41 patients with normozoospermia were included in the control group and 117 patients with non-normozoospermia were included in the study group according to the proportions of all enrolled patients. Cytokinesis-block micronucleus (CBMN) screening was conducted through peripheral blood. Statistical analysis was used to determine the differences in micronuclei (MNi) among the groups and the relationships between MNi and clinical data. There was a significant increase in MNi in infertile men, including those with azoospermia, compared with normozoospermic patients, but there was no significant difference between the genetic and nongenetic groups in azoospermic men. The presence of MNi was associated with sperm concentration, progressive sperm motility, immotile spermatozoa, malformed spermatozoa, total sperm count, and total sperm motility. This study underscores the potential utility of MNi as a diagnostic tool and highlights the need for further research to elucidate the underlying mechanisms of male infertility.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
Background:Pancreatic cancer is a common malignancy with poor prognosis and limited treatment.Here we aimed to investigate the role of host chromosomal instability(CIN)and tumor microbiome in the prognosis of pancreat...Background:Pancreatic cancer is a common malignancy with poor prognosis and limited treatment.Here we aimed to investigate the role of host chromosomal instability(CIN)and tumor microbiome in the prognosis of pancreatic cancer patients.Methods:One hundred formalin-fixed paraffin-embedded(FFPE)pancreatic cancer samples were collected.DNA extracted from FFPE samples were analyzed by low-coverage whole-genome sequencing(WGS)via a customized bioinformatics workflow named ultrasensitive chromosomal aneuploidy detector.Results:Samples were tested according to the procedure of ultrasensitive chromosomal aneuploidy detector(UCAD).We excluded 2 samples with failed quality control,1 patient lost to follow-up and 6 dead in the perioperative period.The final 91 patients were admitted for the following analyses.Thirteen(14.3%)patients with higher CIN score had worse overall survival(OS)than those with lower CIN score.The top 20 microbes in pancreatic cancer samples included 15 species of bacteria and 5 species of viruses.Patients with high human herpesvirus(HHV)-7 and HHV-5 DNA reads exhibited worse OS.Furthermore,we classified 91 patients into 3 subtypes.Patients with higher CIN score(n=13)had the worst prognosis(median OS 6.9 mon);patients with lower CIN score but with HHV-7/5 DNA load(n=24)had worse prognosis(median OS 10.6 mon);while patients with lower CIN score and HHV-7/5 DNA negative(n=54)had the best prognosis(median OS 21.1 mon).Conclusions:High CIN and HHV-7/5 DNA load were associated with worse survival of pancreatic cancer.The novel molecular subtypes of pancreatic cancer based on CIN and microbiome had prognostic value.展开更多
BACKGROUND Few studies have reported an association between an increased risk of acquiring cancers and survival in patients with 4q deletion syndrome.This study presents a rare association between chromosome 4q abnorm...BACKGROUND Few studies have reported an association between an increased risk of acquiring cancers and survival in patients with 4q deletion syndrome.This study presents a rare association between chromosome 4q abnormalities and fallopian tube highgrade serous carcinoma(HGSC)in a young woman.CASE SUMMARY A 35-year-old woman presented with acute dull abdominal pain and a known chromosomal abnormality involving 4q13.3 duplication and 4q23q24 deletion.Upon arrival at the emergency room,her abdomen appeared ovoid and distended with palpable shifting dullness.Ascites were identified through abdominal ultrasound,and computed tomography revealed an omentum cake and an enlarged bilateral adnexa.Blood tests showed elevated CA-125 levels.Paracentesis was conducted,and immunohistochemistry indicated that the cancer cells favored an ovarian origin,making us suspect ovarian cancer.The patient underwent debulking surgery,which led to a diagnosis of stage IIIC HGSC of the fallopian tube.Subsequently,the patient received adjuvant chemotherapy with carboplatin and paclitaxel,resulting in stable current condition.CONCLUSION This study demonstrates a rare correlation between a chromosome 4q abnormality and HGSC.UBE2D3 may affect crucial cancer-related pathways,including P53,BRCA,cyclin D,and tyrosine kinase receptors,thereby possibly contributing to cancer development.In addition,ADH1 and DDIT4 may be potential influencers of both carcinogenic and therapeutic responses.展开更多
Gastric cancer(GC)is a prevalent malignant tumor within the digestive system,with over 40%of new cases and deaths related to GC globally occurring in China.Despite advancements in treatment modalities,such as surgery ...Gastric cancer(GC)is a prevalent malignant tumor within the digestive system,with over 40%of new cases and deaths related to GC globally occurring in China.Despite advancements in treatment modalities,such as surgery supplemented by adjuvant radiotherapy or chemotherapeutic agents,the prognosis for GC remains poor.New targeted therapies and immunotherapies are currently under invest-igation,but no significant breakthroughs have been achieved.Studies have indicated that GC is a heterogeneous disease,encompassing multiple subtypes with distinct biological characteristics and roles.Consequently,personalized treatment based on clinical features,pathologic typing,and molecular typing is crucial for the diagnosis and management of precancerous lesions of gastric cancer(PLGC).Current research has categorized GC into four subtypes:Epstein-Barr virus-positive,microsatellite instability,genome stability,and chromosome instability(CIN).Technologies such as multi-omics analysis and gene sequencing are being employed to identify more suitable novel testing methods in these areas.Among these,ultrasensitive chromosomal aneuploidy detection(UCAD)can detect CIN at a genome-wide level in subjects using low-depth whole genome sequencing technology,in conjunction with bioinformatics analysis,to achieve qualitative and quantitative detection of chromosomal stability.This editorial reviews recent research advancements in UCAD technology for the diagnosis and management of PLGC.展开更多
Objective:To analyze the clinical value of non-invasive prenatal testing(NIPT)in detecting chromosomal copy number variations(CNVs)and to explore the relationship between gene expression and clinical manifestations of...Objective:To analyze the clinical value of non-invasive prenatal testing(NIPT)in detecting chromosomal copy number variations(CNVs)and to explore the relationship between gene expression and clinical manifestations of chromosomal copy number variations.Methods:3551 naturally conceived singleton pregnant women who underwent NIPT were included in this study.The NIPT revealed abnormalities other than sex chromosome abnormalities and trisomy 13,18,and 21.Pregnant women with chromosome copy number variations underwent genetic counseling and prenatal ultrasound examination.Interventional prenatal diagnosis and chromosome microarray analysis(CMA)were performed.The clinical phenotypes and pregnancy outcomes of different prenatal diagnoses were analyzed.Additionally,a follow-up was conducted by telephone to track fetal development after birth,at six months,and one year post-birth.Results:A total of 53 cases among 3551 cases showed chromosomal copy number variation.Interventional prenatal diagnosis was performed in 36 cases:27 cases were negative and 8 were consistent with the NIPT test results.This indicates that NIPT’s positive predictive value(PPV)in CNVs is 22.22%.Conclusion:NIPT has certain clinical significance in screening chromosome copy number variations and is expected to become a routine screening for chromosomal microdeletions and microduplications.However,further interventional prenatal diagnosis is still needed to identify fetal CNVs.展开更多
The plasmid-expression system is routinely plagued by potential plasmid instability. Chromosomal integration is one powerful approach to overcome the problem. Herein we report a plasmid-free hyper-producer E.coli stra...The plasmid-expression system is routinely plagued by potential plasmid instability. Chromosomal integration is one powerful approach to overcome the problem. Herein we report a plasmid-free hyper-producer E.coli strain for coenzyme Q10 production. A series of integration expression vectors, pxKC3T5b and pxKT5b, were constructed for chemically inducible chromosomal evolution(multiple copy integration) and replicon-free and markerless chromosomal integration(single copy integration), respectively. A coenzyme Q10 hyper-producer Escherichia coli TBW20134 was constructed by applying chemically inducible chromosomal evolution,replicon-free and markerless chromosomal integration as well as deletion of menaquinone biosynthetic pathway.The engineered E. coli TBW20134 produced 10.7 mg per gram of dry cell mass(DCM) of coenzyme Q10 when supplemented with 0.075 g·L-1of 4-hydroxy benzoic acid; this yield is unprecedented in E. coli and close to that of the commercial producer Agrobacterium tumefaciens. With this strain, the coenzyme Q10 production capacity was very stable after 30 sequential transfers and no antibiotics were required during the fermentation process. The strategy presented may be useful as a general approach for construction of stable production strains synthesizing natural products where various copy numbers for different genes are concerned.展开更多
In this Editorial review,we would like to focus on a very recent discovery showing the global autosomal gene regulation by Y-and inactivated X-chromosomal transcription factors,zinc finger gene on the Y chromosome(ZFY...In this Editorial review,we would like to focus on a very recent discovery showing the global autosomal gene regulation by Y-and inactivated X-chromosomal transcription factors,zinc finger gene on the Y chromosome(ZFY)and zinc finger protein X-linked(ZFX).ZFX and ZFY are both zinc-finger proteins that encode general transcription factors abundant in hematopoietic and embryonic stem cells.Although both proteins are homologs,interestingly,the regulation of self-renewal by these transcriptional factors is almost exclusive to ZFX.This fact implies that there are some differential roles between ZFX and ZFY in regulating the maintenance of self-renewal activity in stem cells.Besides the maintenance of stemness,ZFX overexpression or mutations may be linked to certain cancers.Although cancers and stem cells are double-edged swords,there is no study showing the link between ZFX activity and the telomere.Thus,stemness or cancers with ZFX may be linked to other molecules,such as Oct4,Sox2,Klf4,and others.Based on very recent studies and a few lines of evidence in the past decade,it appears that the ZFX is linked to the canonical Wnt signaling,which is one possible mechanism to explain the role of ZFX in the self-renewal of stem cells.展开更多
Infertility in humans is surprisingly common occurring in approximately 15% of the population wishing to start a family. Despite this, the molecular and genetic factors underlying the cause of infertility remain large...Infertility in humans is surprisingly common occurring in approximately 15% of the population wishing to start a family. Despite this, the molecular and genetic factors underlying the cause of infertility remain largely undiscovered. Nevertheless, more and more genetic factors associated with infertility are being identified. This review will focus on our current understanding of the chromosomal basis of male infertility specifically： chromosomal aneuploidy, structural and numerical karyotype abnormalities and Y chromosomal microdeletions. Chromosomal aneuploidy is the leading cause of pregnancy loss and developmental disabilities in humans. Aneuploidy is predominantly maternal in origin, but concerns have been raised regarding the safety of intracytoplasmic sperm injection as infertile men have significantly higher levels of sperm aneuploidy compared to their fertile counterparts. Males with numerical or structural karyotype abnormalities are also at an increased risk of producing aneuploid sperm. Our current understanding of how sperm aneuploidy translates to embryo aneuploidy will be reviewed, as well as the application of preimplantation genetic diagnosis （PGD） in such cases. Clinical recommendations where possible will be made, as well as discussion of the use of emerging array technology in PGD and its potential applications in male infertility.展开更多
A total of 1,160 differentially expressed genes induced by Marssonina brunnea f. sp. muhigermtubi were identified in Populus deltoides cv. ＇Lux＇ （1-69/55） with two-colour cDNA microarray including 2,952 cDNAs from...A total of 1,160 differentially expressed genes induced by Marssonina brunnea f. sp. muhigermtubi were identified in Populus deltoides cv. ＇Lux＇ （1-69/55） with two-colour cDNA microarray including 2,952 cDNAs from two cDNA libraries constructed with 72 h inoculated poplar leaves. Functional analysis showed that 1,160 genes were classified into 11 functional categories that are involved in metabolism （15.9%）, signal transduction （9.5%）, transcription and replication （8.7%）, and cell rescue and defense （7.8%）. Among them, 926 genes were sporadically localized on 19 linkage groups. Chromosome 2 contained 102 （11%） differentially expressed genes, followed by chromosome 1 which contains 93 genes （10%）, and chromosome 17 had the least number of differentially expressed genes. Clustering of expressed sequence tags （ESTs） in poplar genome was observed at the terminal regions of several chromosomes. The relationship between cluster of genes and plant defense response would be further studied.展开更多
Chromosomal fragile sites (CFSs) are loci or regions susceptible to spontaneous or induced occurrence of gaps, breaks and rearrangements. In this work, we studied the data of 4535 patients stored at DECIPHER (Database...Chromosomal fragile sites (CFSs) are loci or regions susceptible to spontaneous or induced occurrence of gaps, breaks and rearrangements. In this work, we studied the data of 4535 patients stored at DECIPHER (Database of Chromosomal Imbalance and Phenotype in Humans Using Ensembl Resources). We mapped fragile sites to chromosomal bands and divided the 23 chromosomes into fragile and non-fragile sites. The frequency of rearrangements at the chromosomal location of clones found to be deleted or duplicated in the array/CGH analysis, provided by DECIPHER, was compared in Chromosomal Fragile Sites vs. non-Fragile Sites of the human genome. The POSSUM Web was used to complement this study. The results indicated 1) a predominance of rearrangements in CFSs, 2) the absence of statistically significant difference between the frequency of rearrangements in common CFSs vs. rare CFSs, 3) a predominance of deletions over duplications in CFSs. These results on constitutional chromosomal rearrangements are evocative of the findings previously reported by others relatively to cancer supporting the current line of evidence and suggesting that a common mechanism can underlie the generation of constitutional and somatic rearrangements. The combination of insights obtained from our results and their interrelationships can indicate strategies by which the mechanisms can be targeted with preventive medical interventions.展开更多
Chinese tree shrews (Tupaia belangeri chinensis) have become an increasingly important experimental animal in biomedical research due to their close relationship to primates. An accurately sequenced and assembled geno...Chinese tree shrews (Tupaia belangeri chinensis) have become an increasingly important experimental animal in biomedical research due to their close relationship to primates. An accurately sequenced and assembled genome is essential for understanding the genetic features and biology of this animal. In this study, we used long-read single-molecule sequencing and high-throughput chromosome conformation capture (Hi-C) technology to obtain a high-qualitychromosome-scale scaffolding of the Chinese tree shrew genome. The new reference genome (KIZ version 2: TS_2.0) resolved problems in presently available tree shrew genomes and enabled accurate identification of large and complex repeat regions, gene structures, and species-specific genomic structural variants. In addition, by sequencing the genomes of six Chinese tree shrew individuals, we produced a comprehensive map of 12.8 M single nucleotide polymorphisms and confirmed that the major histocompatibility complex (MHC) loci and immunoglobulin gene family exhibited high nucleotide diversity in the tree shrew genome. We updated the tree shrew genome database (TreeshrewDB v2.0: http://www.treeshrewdb.org) to include the genome annotation information and genetic variations. The new high-quality reference genome of the Chinese tree shrew and the updated TreeshrewDB will facilitate the use of this animal in many different fields of research.展开更多
AIM To explore the correlation of metabolomics profiles ofgastric cancer(GC) with its chromosomal instability(CIN) status.METHODS Nineteen GC patients were classified as CIN and nonCIN type by The Cancer Genome Atlas ...AIM To explore the correlation of metabolomics profiles ofgastric cancer(GC) with its chromosomal instability(CIN) status.METHODS Nineteen GC patients were classified as CIN and nonCIN type by The Cancer Genome Atlas Research Group system, based on 409 oncogenes and tumor suppressor genes sequenced. The aqueous metabolites of the GC tumor and its surrounding adjacent healthy tissues were identified through liquid chromatographymass spectrometry. Groups were compared by defining variable importance in projection score of > 1.2, a fold change value or its reciprocal of > 1.2, and a P value of < 0.05 as a significant difference.RESULTS In total,twelve men and seven women were enrolled, with a median age of 66 years(range, 47-87 years). The numbers of gene alterations in the CIN GC group were significantly higher than those in the non-CIN GC(32-218 vs 2-17; P < 0.0005). Compared with the adjacent healthy tissues, GC tumors demonstrated significantly higher aspartic acid, citicoline, glutamic acid, oxidized glutathione, succinyladenosine, and uridine diphosphate-Nacetylglucosamine levels, but significantly lower butyrylcarnitine, glutathione hydroxyhexanoycarnitine, inosinic acid, isovalerylcarnitine, and threonine levels(all P < 0.05). CIN tumors contained significantly higher phosphocholine and uridine 5'-monophosphate levels but significantly lower beta-citryl-L-glutamic acid levels than did non-CIN tumors(all P < 0.05). CIN GC tumors demonstrated additional altered pathways involving alanine, aspartate, and glutamate metabolism, glyoxylate and dicarboxylate metabolism, histidine metabolism, and phenylalanine, tyrosine, and tryptophan biosynthesis.CONCLUSION Metabolomic profiles of GC tumors and the adjacent healthy tissue are distinct, and the CIN status is associated with downstream metabolic alterations in GC.展开更多
In order to develop more wheat-Haynaldia villosa translocations involving different chromosomes and chromosome segments of H. villosa, T. durum-H, villosa amphiploid was irradiated with ^60Co γ-rays at doses of 800, ...In order to develop more wheat-Haynaldia villosa translocations involving different chromosomes and chromosome segments of H. villosa, T. durum-H, villosa amphiploid was irradiated with ^60Co γ-rays at doses of 800, 1,200, and 1,600 rad. Pollen collected from the spikes 1, 2, and 3 days after irradiation were transferred to emasculated spikes of the common wheat cv. ‘Chinese Spring＇. Genomic in situ hybridization was used to identify wheat-H, villosa chromosome translocations in the M1 generation. Transmission of the identified translocation chromosomes was analyzed in the BC1, BC2, and BC3 generations. The results indicated that all three irradiation doses were highly efficient for inducing wheat-alien translocations without affecting the viability of the M1 seeds. Within the range of 800-1,600 rad, both the efficiency of translocation induction and the frequency of interstitial chromosome breakage-fusion increased as the irradiation dosage increased. A higher translocation induction frequency was observed using pollen collected from the spikes 1 day after irradiation over that of 2 or 3 days after irradiation. More than 70% of the translocations detected in the M1 generation were transmitted to the BC1 through the female gametes. All translocations recovered in the BC1 generation were recovered in the following BC2, and BC3 generations. The transmission ability of different translocation types in different genetic backgrounds showed an order of ‘whole-arm translocation 〉 small alien segment translocation 〉 large alien segment translocation＇, through either male or female gametes, In general, the transmission ability through the female gametes was higher than that through the male gametes. By this approach, 14 translocation lines that involved different H. villosa chromosomes have been identified in the BC3 using EST-STS markers, and eight of them were homozygous.展开更多
As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivat...As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivated wheat has been dramatically narrowed by genetic erosion under the modem cultivation system, resulting in vulnerability to biotic and abiotic stresses （Jiang et al., 1994; Friebe et al., 1996）. The wild relatives of wheat represent a large reservoir of superior genes, and transferring these alien genes to modem cultivars through chromosome engineering is a successful method of broadening the genetic diversity of wheat （Chen et al., 2003;展开更多
Transfer DNA （T-DNA） of Agrobacterium tumefaciens integration in the plant genome may lead to rearrangements of host plant chromosomal fragments, including inversions. However, there is very little information conce...Transfer DNA （T-DNA） of Agrobacterium tumefaciens integration in the plant genome may lead to rearrangements of host plant chromosomal fragments, including inversions. However, there is very little information concerning the inversion. The present study re- ports a transgenic rice line selected from a T-DNA tagged population, which displays a semi-dwarf phenotype. Molecular analysis of this mutant indicated an insertion of two tandem copies of T-DNA into a locus on the rice genome in a head to tail mode. This insertion of T-DNA resulted in the inversion of a 4.9 Mb chromosomal segment. Results of sequence analysis suggest that the chromosomal inversion resulted from the insertion of T-DNA with the help of sequence microhomology between insertion region of T-DNA and target sequence of the host plant.展开更多
In this study, freeze-dried water extract from the leaves of Myristica fragrans （Houtt.） was tested for mutagenic and antimutagenic potentials using the Allium cepa assay. Freeze-dried water extract alone and its co...In this study, freeze-dried water extract from the leaves of Myristica fragrans （Houtt.） was tested for mutagenic and antimutagenic potentials using the Allium cepa assay. Freeze-dried water extract alone and its combination with cyclophosphamide （CP） （50 mg/kg） were separately dissolved in tap water at 500, 1000, 2000, and 4000 mg/kg. Onions （A. cepa） were suspended in the solutions and controls for 48 h in the dark. Root tips were prepared for microscopic evaluation. 2,2-Diphenyl-l-picrylhydrazyl （DPPH） free radicals＇ scavenging power of the extract was tested using butylated hydroxyanisole （BHA） and butylated hydroxytoluene （BHT） as standards. Water extract of Myristica fragrans scavenged free radicals better than BHA, but worse than BHT. The extract alone, as well as in combination with CP suppressed cell division, and induced chromosomal aberrations that were insignificantly different from the negative control （P≤0.05）. However, cytotoxic and mutagenic actions of CP were considerably suppressed. The observed effects on cell division and chromosomes of A. cepa may be principally connected to the antioxidant properties of the extract. The obtained results suggest mitodepressive and antimutagenic potentials of water extract of the leaves of M. fragrans as desirable properties of a promising anticancer agent.展开更多
GPX-GI is a cytosolic tetrameric Se-dependent glutathione peroxidase, similar in properties to GPX-1. Unlike the almost ubiquitous GPX-1, GPX-GI is mainly expressed in the epithelium of gastrointestinal tract. GPX-GI ...GPX-GI is a cytosolic tetrameric Se-dependent glutathione peroxidase, similar in properties to GPX-1. Unlike the almost ubiquitous GPX-1, GPX-GI is mainly expressed in the epithelium of gastrointestinal tract. GPX-GI contributes to at least fifty percent of GPX activity in rodent small intestmal epithelium. The total GPX activity consists of at least 70% of selenium-dependent GPX activity in this compartment.By analyzing a panel of mouse mterspecies DNA from the Jackson Laboratory's backcross resource,we mapped Gpx2 gene to mouse chromosome 12 between D12Mit4 and D12Mit5, near the Ccs1 locus which contains a colon cancer susceptibility gene. A pseudogene, Gpx2-ps is mapped to mouse chromosome 7.Comparison of Gpx2 gene expression in three pairs of C57BL/6Ha and ICR/Ha mice which are respectively resistant and sensitive to dimethylhydrazine-induced colon cancer, we found a higher Gpx2 mRNA level in C57BL/6Ha colon than ICR/Ha colon. Interestingly, a lower level of GPX activity is found in the resistant strain of mice. Because GPX-1 has three times higher specific activity than GPX GI, our data suggest that the decreased GPX activity may result from a higher level of Gpx2 gene expression in those cells co-express GPx1 gene展开更多
基金support through Manipal University Jaipur for the Enhanced Seed Grant under the Endowment Fund(Grant No.E3/2023-24/QE-04-05).
文摘Dear Editor,Lung cancer is a major global health concern,with 2.2 million patients diagnosed in 2020.Non-small cell lung cancer(NSCLC)accounts for 80%of these cases,primarily comprising two subtypes:lung adenocarcinoma(LUAD)and squamous cell carcinoma(LUSC)[1].Researchers use immunohisto-chemistry,next-generation sequencing,and single-cell RNA sequencing to study genetic alterations,tumor heterogeneity,and tumor microenvironments,aiming to identify potential therapeutic options for specific NSCLC subtypes[2].
基金CAs Youth Interdisciplinary Team(JCTD-2022-06)the National Nature Science Foundation of China(31870209).
文摘Chromosomal rearrangements(CRs)often cause phenotypic variations.Although several major rearrangements have been identified in Triticeae,a comprehensive study of the order,timing,and breakpoints of CRs has not been conducted.Here,we reconstruct high-quality ancestral genomes for the most recent common ancestor(MRCA)of the Triticeae,and the MRCA of the wheat lineage(Triticum and Aegilops).The protogenes of MRCA of the Triticeae and the wheat lineage are 22,894 and 29,060,respectively,which were arranged in their ancestral order.By partitioning modern Triticeae chromosomes into sets of syntenic regions and linking each to the corresponding protochromosomes,we revisit the rye chromosome structural evolution and propose alternative evolutionary routes.The previously identified 4L/5L reciprocal translocation in rye and Triticum urartu is found to have occurred independently and is unlikely to be the result of chromosomal introgression following distant hybridization.We also clarify that the 4AL/7BS translocation in tetraploid wheat was a bidirectional rather than unidirectional translocation event.Lastly,we identify several breakpoints in protochromosomes that independently reoccur following Triticeae evolution,representing potential CR hotspots.This study demonstrates that these reconstructed ancestral genomes can serve as special comparative references and facilitate a better understanding of the evolution of structural rearrangements in Triticeae.
基金supported by the National Natural Science Foundation of China(No.32070582)the Joint Foundation of He Lin Academical Workstation of the Third Affiliated Hospital of Guangzhou Medical University(2023HLLH01)the Plan on enhancing scientific research in GMU(2024SRP125).
文摘Investigating the correlation between micronucleus formation and male infertility has the potential to improve clinical diagnosis and deepen our understanding of pathological progression. Our study enrolled 2252 male patients whose semen was analyzed from March 2023 to July 2023. Their clinical data, including semen parameters and age, were also collected. Genetic analysis was used to determine whether the sex chromosome involved in male infertility was abnormal (including the increase, deletion, and translocation of the X and Y chromosomes), and subsequent semen analysis was conducted for clinical grouping purposes. The participants were categorized into five groups: normozoospermia, asthenozoospermia, oligozoospermia, oligoasthenozoospermia, and azoospermia. Patients were randomly selected for further study;41 patients with normozoospermia were included in the control group and 117 patients with non-normozoospermia were included in the study group according to the proportions of all enrolled patients. Cytokinesis-block micronucleus (CBMN) screening was conducted through peripheral blood. Statistical analysis was used to determine the differences in micronuclei (MNi) among the groups and the relationships between MNi and clinical data. There was a significant increase in MNi in infertile men, including those with azoospermia, compared with normozoospermic patients, but there was no significant difference between the genetic and nongenetic groups in azoospermic men. The presence of MNi was associated with sperm concentration, progressive sperm motility, immotile spermatozoa, malformed spermatozoa, total sperm count, and total sperm motility. This study underscores the potential utility of MNi as a diagnostic tool and highlights the need for further research to elucidate the underlying mechanisms of male infertility.
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 grants from the National Natural Science Foundation of China(82171757)the Zhejiang Provincial Natural Science Foundation of China(LZ22H030004 and LQ20H160048).
文摘Background:Pancreatic cancer is a common malignancy with poor prognosis and limited treatment.Here we aimed to investigate the role of host chromosomal instability(CIN)and tumor microbiome in the prognosis of pancreatic cancer patients.Methods:One hundred formalin-fixed paraffin-embedded(FFPE)pancreatic cancer samples were collected.DNA extracted from FFPE samples were analyzed by low-coverage whole-genome sequencing(WGS)via a customized bioinformatics workflow named ultrasensitive chromosomal aneuploidy detector.Results:Samples were tested according to the procedure of ultrasensitive chromosomal aneuploidy detector(UCAD).We excluded 2 samples with failed quality control,1 patient lost to follow-up and 6 dead in the perioperative period.The final 91 patients were admitted for the following analyses.Thirteen(14.3%)patients with higher CIN score had worse overall survival(OS)than those with lower CIN score.The top 20 microbes in pancreatic cancer samples included 15 species of bacteria and 5 species of viruses.Patients with high human herpesvirus(HHV)-7 and HHV-5 DNA reads exhibited worse OS.Furthermore,we classified 91 patients into 3 subtypes.Patients with higher CIN score(n=13)had the worst prognosis(median OS 6.9 mon);patients with lower CIN score but with HHV-7/5 DNA load(n=24)had worse prognosis(median OS 10.6 mon);while patients with lower CIN score and HHV-7/5 DNA negative(n=54)had the best prognosis(median OS 21.1 mon).Conclusions:High CIN and HHV-7/5 DNA load were associated with worse survival of pancreatic cancer.The novel molecular subtypes of pancreatic cancer based on CIN and microbiome had prognostic value.
文摘BACKGROUND Few studies have reported an association between an increased risk of acquiring cancers and survival in patients with 4q deletion syndrome.This study presents a rare association between chromosome 4q abnormalities and fallopian tube highgrade serous carcinoma(HGSC)in a young woman.CASE SUMMARY A 35-year-old woman presented with acute dull abdominal pain and a known chromosomal abnormality involving 4q13.3 duplication and 4q23q24 deletion.Upon arrival at the emergency room,her abdomen appeared ovoid and distended with palpable shifting dullness.Ascites were identified through abdominal ultrasound,and computed tomography revealed an omentum cake and an enlarged bilateral adnexa.Blood tests showed elevated CA-125 levels.Paracentesis was conducted,and immunohistochemistry indicated that the cancer cells favored an ovarian origin,making us suspect ovarian cancer.The patient underwent debulking surgery,which led to a diagnosis of stage IIIC HGSC of the fallopian tube.Subsequently,the patient received adjuvant chemotherapy with carboplatin and paclitaxel,resulting in stable current condition.CONCLUSION This study demonstrates a rare correlation between a chromosome 4q abnormality and HGSC.UBE2D3 may affect crucial cancer-related pathways,including P53,BRCA,cyclin D,and tyrosine kinase receptors,thereby possibly contributing to cancer development.In addition,ADH1 and DDIT4 may be potential influencers of both carcinogenic and therapeutic responses.
文摘Gastric cancer(GC)is a prevalent malignant tumor within the digestive system,with over 40%of new cases and deaths related to GC globally occurring in China.Despite advancements in treatment modalities,such as surgery supplemented by adjuvant radiotherapy or chemotherapeutic agents,the prognosis for GC remains poor.New targeted therapies and immunotherapies are currently under invest-igation,but no significant breakthroughs have been achieved.Studies have indicated that GC is a heterogeneous disease,encompassing multiple subtypes with distinct biological characteristics and roles.Consequently,personalized treatment based on clinical features,pathologic typing,and molecular typing is crucial for the diagnosis and management of precancerous lesions of gastric cancer(PLGC).Current research has categorized GC into four subtypes:Epstein-Barr virus-positive,microsatellite instability,genome stability,and chromosome instability(CIN).Technologies such as multi-omics analysis and gene sequencing are being employed to identify more suitable novel testing methods in these areas.Among these,ultrasensitive chromosomal aneuploidy detection(UCAD)can detect CIN at a genome-wide level in subjects using low-depth whole genome sequencing technology,in conjunction with bioinformatics analysis,to achieve qualitative and quantitative detection of chromosomal stability.This editorial reviews recent research advancements in UCAD technology for the diagnosis and management of PLGC.
基金Dongguan City Social Development Project(Project number:20161081101023)。
文摘Objective:To analyze the clinical value of non-invasive prenatal testing(NIPT)in detecting chromosomal copy number variations(CNVs)and to explore the relationship between gene expression and clinical manifestations of chromosomal copy number variations.Methods:3551 naturally conceived singleton pregnant women who underwent NIPT were included in this study.The NIPT revealed abnormalities other than sex chromosome abnormalities and trisomy 13,18,and 21.Pregnant women with chromosome copy number variations underwent genetic counseling and prenatal ultrasound examination.Interventional prenatal diagnosis and chromosome microarray analysis(CMA)were performed.The clinical phenotypes and pregnancy outcomes of different prenatal diagnoses were analyzed.Additionally,a follow-up was conducted by telephone to track fetal development after birth,at six months,and one year post-birth.Results:A total of 53 cases among 3551 cases showed chromosomal copy number variation.Interventional prenatal diagnosis was performed in 36 cases:27 cases were negative and 8 were consistent with the NIPT test results.This indicates that NIPT’s positive predictive value(PPV)in CNVs is 22.22%.Conclusion:NIPT has certain clinical significance in screening chromosome copy number variations and is expected to become a routine screening for chromosomal microdeletions and microduplications.However,further interventional prenatal diagnosis is still needed to identify fetal CNVs.
基金Supported by the National Natural Science Foundation of China(30970089,20876181,21276289)the Natural Science Foundation of Guangdong Province(9351027501000003,S2011010001396)
文摘The plasmid-expression system is routinely plagued by potential plasmid instability. Chromosomal integration is one powerful approach to overcome the problem. Herein we report a plasmid-free hyper-producer E.coli strain for coenzyme Q10 production. A series of integration expression vectors, pxKC3T5b and pxKT5b, were constructed for chemically inducible chromosomal evolution(multiple copy integration) and replicon-free and markerless chromosomal integration(single copy integration), respectively. A coenzyme Q10 hyper-producer Escherichia coli TBW20134 was constructed by applying chemically inducible chromosomal evolution,replicon-free and markerless chromosomal integration as well as deletion of menaquinone biosynthetic pathway.The engineered E. coli TBW20134 produced 10.7 mg per gram of dry cell mass(DCM) of coenzyme Q10 when supplemented with 0.075 g·L-1of 4-hydroxy benzoic acid; this yield is unprecedented in E. coli and close to that of the commercial producer Agrobacterium tumefaciens. With this strain, the coenzyme Q10 production capacity was very stable after 30 sequential transfers and no antibiotics were required during the fermentation process. The strategy presented may be useful as a general approach for construction of stable production strains synthesizing natural products where various copy numbers for different genes are concerned.
文摘In this Editorial review,we would like to focus on a very recent discovery showing the global autosomal gene regulation by Y-and inactivated X-chromosomal transcription factors,zinc finger gene on the Y chromosome(ZFY)and zinc finger protein X-linked(ZFX).ZFX and ZFY are both zinc-finger proteins that encode general transcription factors abundant in hematopoietic and embryonic stem cells.Although both proteins are homologs,interestingly,the regulation of self-renewal by these transcriptional factors is almost exclusive to ZFX.This fact implies that there are some differential roles between ZFX and ZFY in regulating the maintenance of self-renewal activity in stem cells.Besides the maintenance of stemness,ZFX overexpression or mutations may be linked to certain cancers.Although cancers and stem cells are double-edged swords,there is no study showing the link between ZFX activity and the telomere.Thus,stemness or cancers with ZFX may be linked to other molecules,such as Oct4,Sox2,Klf4,and others.Based on very recent studies and a few lines of evidence in the past decade,it appears that the ZFX is linked to the canonical Wnt signaling,which is one possible mechanism to explain the role of ZFX in the self-renewal of stem cells.
文摘Infertility in humans is surprisingly common occurring in approximately 15% of the population wishing to start a family. Despite this, the molecular and genetic factors underlying the cause of infertility remain largely undiscovered. Nevertheless, more and more genetic factors associated with infertility are being identified. This review will focus on our current understanding of the chromosomal basis of male infertility specifically： chromosomal aneuploidy, structural and numerical karyotype abnormalities and Y chromosomal microdeletions. Chromosomal aneuploidy is the leading cause of pregnancy loss and developmental disabilities in humans. Aneuploidy is predominantly maternal in origin, but concerns have been raised regarding the safety of intracytoplasmic sperm injection as infertile men have significantly higher levels of sperm aneuploidy compared to their fertile counterparts. Males with numerical or structural karyotype abnormalities are also at an increased risk of producing aneuploid sperm. Our current understanding of how sperm aneuploidy translates to embryo aneuploidy will be reviewed, as well as the application of preimplantation genetic diagnosis （PGD） in such cases. Clinical recommendations where possible will be made, as well as discussion of the use of emerging array technology in PGD and its potential applications in male infertility.
基金National Natural Science Foundation of China (No. 30230300).
文摘A total of 1,160 differentially expressed genes induced by Marssonina brunnea f. sp. muhigermtubi were identified in Populus deltoides cv. ＇Lux＇ （1-69/55） with two-colour cDNA microarray including 2,952 cDNAs from two cDNA libraries constructed with 72 h inoculated poplar leaves. Functional analysis showed that 1,160 genes were classified into 11 functional categories that are involved in metabolism （15.9%）, signal transduction （9.5%）, transcription and replication （8.7%）, and cell rescue and defense （7.8%）. Among them, 926 genes were sporadically localized on 19 linkage groups. Chromosome 2 contained 102 （11%） differentially expressed genes, followed by chromosome 1 which contains 93 genes （10%）, and chromosome 17 had the least number of differentially expressed genes. Clustering of expressed sequence tags （ESTs） in poplar genome was observed at the terminal regions of several chromosomes. The relationship between cluster of genes and plant defense response would be further studied.
基金partially supported by CIGMH/FCM/UNL,under the project PEST-OE/SAU/UI0009/2011CMA/FCT/UNL,under the project PEst-OE/MAT/UI0297/2011.
文摘Chromosomal fragile sites (CFSs) are loci or regions susceptible to spontaneous or induced occurrence of gaps, breaks and rearrangements. In this work, we studied the data of 4535 patients stored at DECIPHER (Database of Chromosomal Imbalance and Phenotype in Humans Using Ensembl Resources). We mapped fragile sites to chromosomal bands and divided the 23 chromosomes into fragile and non-fragile sites. The frequency of rearrangements at the chromosomal location of clones found to be deleted or duplicated in the array/CGH analysis, provided by DECIPHER, was compared in Chromosomal Fragile Sites vs. non-Fragile Sites of the human genome. The POSSUM Web was used to complement this study. The results indicated 1) a predominance of rearrangements in CFSs, 2) the absence of statistically significant difference between the frequency of rearrangements in common CFSs vs. rare CFSs, 3) a predominance of deletions over duplications in CFSs. These results on constitutional chromosomal rearrangements are evocative of the findings previously reported by others relatively to cancer supporting the current line of evidence and suggesting that a common mechanism can underlie the generation of constitutional and somatic rearrangements. The combination of insights obtained from our results and their interrelationships can indicate strategies by which the mechanisms can be targeted with preventive medical interventions.
基金supported by the National Natural Science Foundation of China(U1402224,31601010,81571998,and U1702284)Yunnan Province(2015HA038 and 2018FB054)Chinese Academy of Sciences(CAS zsys-02)
文摘Chinese tree shrews (Tupaia belangeri chinensis) have become an increasingly important experimental animal in biomedical research due to their close relationship to primates. An accurately sequenced and assembled genome is essential for understanding the genetic features and biology of this animal. In this study, we used long-read single-molecule sequencing and high-throughput chromosome conformation capture (Hi-C) technology to obtain a high-qualitychromosome-scale scaffolding of the Chinese tree shrew genome. The new reference genome (KIZ version 2: TS_2.0) resolved problems in presently available tree shrew genomes and enabled accurate identification of large and complex repeat regions, gene structures, and species-specific genomic structural variants. In addition, by sequencing the genomes of six Chinese tree shrew individuals, we produced a comprehensive map of 12.8 M single nucleotide polymorphisms and confirmed that the major histocompatibility complex (MHC) loci and immunoglobulin gene family exhibited high nucleotide diversity in the tree shrew genome. We updated the tree shrew genome database (TreeshrewDB v2.0: http://www.treeshrewdb.org) to include the genome annotation information and genetic variations. The new high-quality reference genome of the Chinese tree shrew and the updated TreeshrewDB will facilitate the use of this animal in many different fields of research.
基金Supported by the Ministry of Science and Technology Taiwan grant,No.MOST 106-2314-B-182A-019-MY3the Chang Gung Foundation,No.CMRPG3E1321-2,No.IRB201601916B0,and No.IRB103-7448B
文摘AIM To explore the correlation of metabolomics profiles ofgastric cancer(GC) with its chromosomal instability(CIN) status.METHODS Nineteen GC patients were classified as CIN and nonCIN type by The Cancer Genome Atlas Research Group system, based on 409 oncogenes and tumor suppressor genes sequenced. The aqueous metabolites of the GC tumor and its surrounding adjacent healthy tissues were identified through liquid chromatographymass spectrometry. Groups were compared by defining variable importance in projection score of > 1.2, a fold change value or its reciprocal of > 1.2, and a P value of < 0.05 as a significant difference.RESULTS In total,twelve men and seven women were enrolled, with a median age of 66 years(range, 47-87 years). The numbers of gene alterations in the CIN GC group were significantly higher than those in the non-CIN GC(32-218 vs 2-17; P < 0.0005). Compared with the adjacent healthy tissues, GC tumors demonstrated significantly higher aspartic acid, citicoline, glutamic acid, oxidized glutathione, succinyladenosine, and uridine diphosphate-Nacetylglucosamine levels, but significantly lower butyrylcarnitine, glutathione hydroxyhexanoycarnitine, inosinic acid, isovalerylcarnitine, and threonine levels(all P < 0.05). CIN tumors contained significantly higher phosphocholine and uridine 5'-monophosphate levels but significantly lower beta-citryl-L-glutamic acid levels than did non-CIN tumors(all P < 0.05). CIN GC tumors demonstrated additional altered pathways involving alanine, aspartate, and glutamate metabolism, glyoxylate and dicarboxylate metabolism, histidine metabolism, and phenylalanine, tyrosine, and tryptophan biosynthesis.CONCLUSION Metabolomic profiles of GC tumors and the adjacent healthy tissue are distinct, and the CIN status is associated with downstream metabolic alterations in GC.
基金supported by the National Natural Science Foundation of China (No.30270827 and 30871519)the High Tech Program of China (No.2006AA100101,2006AA10Z1F6)the Ministry of Educate 111 Project (B08025)
文摘In order to develop more wheat-Haynaldia villosa translocations involving different chromosomes and chromosome segments of H. villosa, T. durum-H, villosa amphiploid was irradiated with ^60Co γ-rays at doses of 800, 1,200, and 1,600 rad. Pollen collected from the spikes 1, 2, and 3 days after irradiation were transferred to emasculated spikes of the common wheat cv. ‘Chinese Spring＇. Genomic in situ hybridization was used to identify wheat-H, villosa chromosome translocations in the M1 generation. Transmission of the identified translocation chromosomes was analyzed in the BC1, BC2, and BC3 generations. The results indicated that all three irradiation doses were highly efficient for inducing wheat-alien translocations without affecting the viability of the M1 seeds. Within the range of 800-1,600 rad, both the efficiency of translocation induction and the frequency of interstitial chromosome breakage-fusion increased as the irradiation dosage increased. A higher translocation induction frequency was observed using pollen collected from the spikes 1 day after irradiation over that of 2 or 3 days after irradiation. More than 70% of the translocations detected in the M1 generation were transmitted to the BC1 through the female gametes. All translocations recovered in the BC1 generation were recovered in the following BC2, and BC3 generations. The transmission ability of different translocation types in different genetic backgrounds showed an order of ‘whole-arm translocation 〉 small alien segment translocation 〉 large alien segment translocation＇, through either male or female gametes, In general, the transmission ability through the female gametes was higher than that through the male gametes. By this approach, 14 translocation lines that involved different H. villosa chromosomes have been identified in the BC3 using EST-STS markers, and eight of them were homozygous.
基金supported by a grant from the National High Technology Research and Development Program("863" Program) of China(No. 2011AA100103)
文摘As a staple food crop for one-third of the world＇s population, common wheat （Triticum aestivum L., 2n = 6x = 42, AABBDD） plays an important role in humans＇ food security. However, the genetic variation of cultivated wheat has been dramatically narrowed by genetic erosion under the modem cultivation system, resulting in vulnerability to biotic and abiotic stresses （Jiang et al., 1994; Friebe et al., 1996）. The wild relatives of wheat represent a large reservoir of superior genes, and transferring these alien genes to modem cultivars through chromosome engineering is a successful method of broadening the genetic diversity of wheat （Chen et al., 2003;
基金supported by the National High Technology Development Program of China (No.2008AA10Z104)China Postdoctoral Science Foundation (No.20060600519)
文摘Transfer DNA （T-DNA） of Agrobacterium tumefaciens integration in the plant genome may lead to rearrangements of host plant chromosomal fragments, including inversions. However, there is very little information concerning the inversion. The present study re- ports a transgenic rice line selected from a T-DNA tagged population, which displays a semi-dwarf phenotype. Molecular analysis of this mutant indicated an insertion of two tandem copies of T-DNA into a locus on the rice genome in a head to tail mode. This insertion of T-DNA resulted in the inversion of a 4.9 Mb chromosomal segment. Results of sequence analysis suggest that the chromosomal inversion resulted from the insertion of T-DNA with the help of sequence microhomology between insertion region of T-DNA and target sequence of the host plant.
文摘In this study, freeze-dried water extract from the leaves of Myristica fragrans （Houtt.） was tested for mutagenic and antimutagenic potentials using the Allium cepa assay. Freeze-dried water extract alone and its combination with cyclophosphamide （CP） （50 mg/kg） were separately dissolved in tap water at 500, 1000, 2000, and 4000 mg/kg. Onions （A. cepa） were suspended in the solutions and controls for 48 h in the dark. Root tips were prepared for microscopic evaluation. 2,2-Diphenyl-l-picrylhydrazyl （DPPH） free radicals＇ scavenging power of the extract was tested using butylated hydroxyanisole （BHA） and butylated hydroxytoluene （BHT） as standards. Water extract of Myristica fragrans scavenged free radicals better than BHA, but worse than BHT. The extract alone, as well as in combination with CP suppressed cell division, and induced chromosomal aberrations that were insignificantly different from the negative control （P≤0.05）. However, cytotoxic and mutagenic actions of CP were considerably suppressed. The observed effects on cell division and chromosomes of A. cepa may be principally connected to the antioxidant properties of the extract. The obtained results suggest mitodepressive and antimutagenic potentials of water extract of the leaves of M. fragrans as desirable properties of a promising anticancer agent.
文摘GPX-GI is a cytosolic tetrameric Se-dependent glutathione peroxidase, similar in properties to GPX-1. Unlike the almost ubiquitous GPX-1, GPX-GI is mainly expressed in the epithelium of gastrointestinal tract. GPX-GI contributes to at least fifty percent of GPX activity in rodent small intestmal epithelium. The total GPX activity consists of at least 70% of selenium-dependent GPX activity in this compartment.By analyzing a panel of mouse mterspecies DNA from the Jackson Laboratory's backcross resource,we mapped Gpx2 gene to mouse chromosome 12 between D12Mit4 and D12Mit5, near the Ccs1 locus which contains a colon cancer susceptibility gene. A pseudogene, Gpx2-ps is mapped to mouse chromosome 7.Comparison of Gpx2 gene expression in three pairs of C57BL/6Ha and ICR/Ha mice which are respectively resistant and sensitive to dimethylhydrazine-induced colon cancer, we found a higher Gpx2 mRNA level in C57BL/6Ha colon than ICR/Ha colon. Interestingly, a lower level of GPX activity is found in the resistant strain of mice. Because GPX-1 has three times higher specific activity than GPX GI, our data suggest that the decreased GPX activity may result from a higher level of Gpx2 gene expression in those cells co-express GPx1 gene
