[Objective] The study aimed to investigate the genetic polymorphism of eighteen Lycium barbarum resources via nrDNA ITS sequencing. [Method] The genomic DNAs from Lycium barbarum leaves were isolated by modified CTAB ...[Objective] The study aimed to investigate the genetic polymorphism of eighteen Lycium barbarum resources via nrDNA ITS sequencing. [Method] The genomic DNAs from Lycium barbarum leaves were isolated by modified CTAB method for PCR amplification on the nrDNA ITS region using specifically synthesized primers; the amplified fragments were cloned and sequenced, then the sequencing results were clustered. [Result] nrDNA ITS sequences of the tested eighteen Lycium barbarum were firstly obtained in the present study. For all eighteen tested materials, the variation range of whole ITS region was 559-634 bp, with an average of 612 bp; alignment analyses showed that the whole length of internal transcribed spacer (ITS1+ITS2) was 480 bp, within which there are 194 variation sites (accounting for 40.4%) and 286 conserved sites (accounting for 59.6%). The cluster results showed that the eighteen tested materials could be grouped into three classes. [Conclusion] Analysis of nrDNA ITS sequence may avail to identify the Lycium barbarum germplasm resources.展开更多
To reveal the genetic structures and relationships of the four ethnic populations from the maternal inheritance and explore the origins and migrations of nationalities, the genetic polymorphism of mtDNA in Dong, Gelao...To reveal the genetic structures and relationships of the four ethnic populations from the maternal inheritance and explore the origins and migrations of nationalities, the genetic polymorphism of mtDNA in Dong, Gelao, Tujia, and Yi populations from Guizhou was studied by direct sequencing of hypervariable segment Ⅰ （HVS Ⅰ ） and PCR-RFLP of coding region. Thirty-seven （sub-） haplogroups were identified in the classification tree of mtDNA haplogroups. Haplogroup distributions and principal component （PC） analysis showed that the Dong has high frequencies of south-prevalent haplogroups, which indicates that it is a typically southern population. The Yi harbors high frequencies of the south-prevalent and northern-prevalent haplogroups, which demonstrates that it inherits the maternal characteristics from both southern and northern populations. The Yi and Gelao cluster together, the reason for which might be that their ancestries frequently underwent gene exchanges and mixtures.展开更多
[ Objective] The relationship between the genetic evolution and phylogenesis of the main grasshopper species in Inner Mongolia grasslands in molecular level was studied. [ Method] Random amplified polymorphic DNA （R...[ Objective] The relationship between the genetic evolution and phylogenesis of the main grasshopper species in Inner Mongolia grasslands in molecular level was studied. [ Method] Random amplified polymorphic DNA （RAPD） technique was used to amplify the 80 individuals of 8 grasshoppers （4 families, 6 genera） in Acridoidea, the polymorphisms of their genomic DNA were compared. [ Result] 64 specific fragments were amplified by 7 primers with the molecular weight of 300 -2 000 bp. The genetic distance between 8 grasshoppers was 0.228 2 -0.589 6. Band pat- tern showed that polymorphism was commonly existed in different genus within the same family and different species within the same genus. The resuits were conducted UPGMA cluster analysis according to Neis＇ genetic distance, the results showed that the species within the same genus first clustered together, then the species in the same family clustered together. [ Condusloa] The study could provide molecular biological basis for system development and evolution research of main grasshoppers in Inner Mongolia grassland.展开更多
Objective To compare the asbestos-induced DNA damage and repair capacities of DNA damage between 104 asbestosexposed workers and 101 control workers in Qingdao City of China and to investigate the possible association...Objective To compare the asbestos-induced DNA damage and repair capacities of DNA damage between 104 asbestosexposed workers and 101 control workers in Qingdao City of China and to investigate the possible association between polymorphisms in codon 399 of XRCC1 and susceptibility to asbestosis. Methods DNA damage levels in peripheral blood lymphocytes were determined by comet assay, and XRCC1 genetic polymorphisms of DNA samples from 51 asbestosis cases and 53 non-asbestosis workers with a similar asbestos exposure history were analyzed by PCR/RFLP. Results The basal comet scores （3.95±2.95） were significantly higher in asbestos-exposed workers than in control workers （0.10±0.28）. After 1 h H2O2 stimulation, DNA damage of lymphocytes exhibited different increases. After a 4 h repair period, the comet scores were 50.98±19.53 in asbestos-exposed workers and 18.32±12.04 in controls. The residual DNA damage （RD） was significantly greater （P〈0.01） in asbestos-exposed workers （35.62%） than in controls （27.75%）. XRCC1 genetic polymorphism in 104 asbestos-exposed workers was not associated with increased risk of asbestosis. But compared with polymorphisms in the DNA repair gene XRCC1 （polymorphisms in codon 399） and the DNA damage induced by asbestos, the comet scores in asbestosis cases with Gin/Gin, Gln/Arg, and Arg/Arg were 40.26±18.94, 38.03±28.22, and 32.01±11.65, respectively, which were higher than those in non-asbestosis workers with the same genotypes （25.58±11.08, 37.08±14.74, and 29.38±10.15）. There were significant differences in the comet scores between asbestosis cases and non-asbestosis workers with Gin/Gin by Student＇s t-test （P〈0.05 or 0.01）. The comet scores were higher in asbestosis workers with Gin/Gin than in those with Arg/Arg and in non-asbestosis workers exposed to asbestos, but without statistically significant difference. Conclusions Exposure to asbestos may be related to DNA damage or the capacity of cells to repair H2O2-induced DNA damage. DNA repair gene XRCC 1 codon 399 may be responsible for the inter-individual susceptibility in DNA damage and repair capacities.展开更多
The chromosomal localization of 45S ribosomal RNA genes in Ambystoma jeffersonianum was determined by fluorescence in situ hybridization with 18S rDNA fragment as a probe (FISH-rDNA). Our results revealed the presence...The chromosomal localization of 45S ribosomal RNA genes in Ambystoma jeffersonianum was determined by fluorescence in situ hybridization with 18S rDNA fragment as a probe (FISH-rDNA). Our results revealed the presence of rDNA polymorphism among A.jeffersonianum populations in terms of number,location and FISH signal intensity on the chromosomes. Nine rDNA cytotypes were found in ten geographically isolated populations and most of them contained derivative rDNA sites. Our preliminary study provides strong indication of karyotypic diversification of A.jeffersonianum that is demonstrated by intraspecific variation of 45S rDNA cytotypes. rDNA cytotype polymorphism has been described in many other caudate amphibians. We predict that habitat isolation,low dispersal ability and decline of effective population size could facilitate the fixation and accumulation of variable rDNA cytotypes during their chromosome evolution.展开更多
The chloroplast DNA （cpDNA） and mitochondrial DNA （mtDNA） of 16 Populus species （Section Leuce） and their F1 generation were detected using PCR-RFLP technique. The results show that cpDNA in the F1 generation of...The chloroplast DNA （cpDNA） and mitochondrial DNA （mtDNA） of 16 Populus species （Section Leuce） and their F1 generation were detected using PCR-RFLP technique. The results show that cpDNA in the F1 generation of 22 hybrid combinations was inherited maternally, which supported the conclusions of the study of plasmid cytology. The mtDNA fragments amplified by PCR were consistent with the restriction maps in all hybrid combinations and no polymorphism was detected, indicating that the Section Leuce is highly conserved in mitochondrial gene sequences. These results provided direct evidence of maternal chloroplast inheritance in Populus tomentosa, P. bolleana, P. davidiana, P. adenopoda, P. tomentosa × P. bolleana, P. alba × P. glandulosa and P. alba × P. tomentosa.展开更多
[ Objective ] This study was to analyze the genetic polymorphism in GDF8 Region of HU sheep. [Method] Four microsatellite loci including BMS1591, TEXAN-2, FCB128 and BM81124 mapped on GDF8 region of chromosome No. 2 o...[ Objective ] This study was to analyze the genetic polymorphism in GDF8 Region of HU sheep. [Method] Four microsatellite loci including BMS1591, TEXAN-2, FCB128 and BM81124 mapped on GDF8 region of chromosome No. 2 of sheep that may be correlated with growth performance were chosen to detect the molecular genetics foundation of growth performance of Hu sheep. [ Result] Four microsatellite loci detected were high in heterozygosity, more in effective alleles number and rich in polymorphic information, all the three indices passed through the high polymorphic level （PIC 〉0.5）. [ Conclusion ] The four microsatellite loci detected could be used to estimate the genetic polymorphism of growth performance of Hu sheep.展开更多
Ecotilling is a new approach based on enzyme-mediated heteroduplex cleavage to discover DNA polymorphisms in natural population. We used mung bean nuclease（MBN） instead of routinely used CELI to cleave single base p...Ecotilling is a new approach based on enzyme-mediated heteroduplex cleavage to discover DNA polymorphisms in natural population. We used mung bean nuclease（MBN） instead of routinely used CELI to cleave single base pair mismatches in heteroduplex DNA templates. Nested set of primers were designed to amplify targeted region to avoid the influence of the variation in quality and quantity of the genomic DNA. To reduce the costs in fluorescently labeled primers, we added M13 adapter to 5＇end of gene specific primers to make IRD dye labeled M13 forward and reverse primers possibly universal for different genes. A Brassica rapa ZIP gene homologue was subjected to the analysis to practise the feasibility of the method in polymorphisms detection. Our experiment showed this method is efficient in discovering DNA polymorphisms in Brassica rapa natural population.展开更多
Investigation of the relationships of phenotypic and epigenetic variations might he a good way to dissect the genetic or molecular basis of phenotypic variation and plasticity in plants, Castor bean （Ricinus cornraun...Investigation of the relationships of phenotypic and epigenetic variations might he a good way to dissect the genetic or molecular basis of phenotypic variation and plasticity in plants, Castor bean （Ricinus cornraunis L）, an important non-edible oilseed crop, is a mono-species genus plant in the family Euphorbiaceae. Since it displays rich phenotypic variations with low genetic diversity, castor bean is a good model to investigate the molecular basis of phenotypic and epigenetic variations. Cytosine DNA methylation represents a major molecular mechanism of epigenetic occurrence. In this study, epigenetic diversity of sixty landrace accessions collected worldwide was investigated using the methylation- sensitive amplification polymorphism （MSAP） technique, Results showed that the epigenetic diversity （based on the polymorphism of DNA methylated loci） exhibited a medium variation （Ne = 1.395, He = 0.242, I = 0.366） at the population level though the variation was great, ranging from 3,80% to 3431% among accessions. Both population structure analysis and the phylogenetic construction （using the neighbor-joining criteria） revealed that the two main clades were identified, but they did not display a distinct geographic structure, After inspecting the location of polymorphic methylated loci on genome we identified that the polymorphic methylated loci occur widely in nuclear and organelle genomes. This study provides new data to understand phenotypic and epigenetic variations in castor bean,展开更多
AIM:To investigate the association between single nucleotide polymorphism (SNP) in promoter of the DNA methyltrans-ferase 3B(DNMT3B) gene and risk for development and lymphatic metastasis of gastric cardiac adenocarci...AIM:To investigate the association between single nucleotide polymorphism (SNP) in promoter of the DNA methyltrans-ferase 3B(DNMT3B) gene and risk for development and lymphatic metastasis of gastric cardiac adenocarcinoma (GCA). METHODS: The hospital based case-control study included 212 GCA patients and 294 control subjects without overt cancer. The DNMT3B SNP was genotyped by PCR and restriction fragment length polymorphism (RFLP) analysis. RESULTS: The C/C genotype was not detected in both GCA patients and controls. In control subjects, the frequency of T/T and C/T genotypes was 94.9% and 5.1% respectively, and that of T and C alleles was 97.4% and 2.6%, respectively. The genotype and allelotype distribution in the GCA patients was not significantly different from that in controls (P=0.34 and 0.33, respectively). When stratified by smoking status and family history of upper gastrointestinal cancer, significant difference in the genotype distribution was not observed between GCA patients and controls. The distribution of DNMT3B genotypes in GCA patents with or without lymphatic metastasis did not show significant difference (P= 0.42). CONCLUSION: The distribution of DNMT3B SNP in North China is distinct from that in Caucasians. Although this SNP has been associated with susceptibility to lung, head, neck and breast cancer, it may not be used as a stratification marker to predict susceptibility and lymphatic metastasis of GCA, at least in the population of North China.展开更多
Research on the identity of genes and their relationship with traits of economic importance in farm animals could assist in the selection of livestock. In this study, the polymorphisms of insulin-like growth factor 1 ...Research on the identity of genes and their relationship with traits of economic importance in farm animals could assist in the selection of livestock. In this study, the polymorphisms of insulin-like growth factor 1 （IGF1） gene in 561 goats of ten breeds were detected by polymerase chain reaction （PCR）-single strand conformation polymorphism （SSCP） and their association with litter size and birth weight in three breeds were investigated. The effects of IGF1 polymorphisms on the breeding value for litter size and birth weight were examined using least square methods. Two deletions （CA） were detected in the microsatellite and two mutations （A1637G, T1640C） were found in 5′-flanking regulatory region. No significant association between the polymorphisms in 5′-flanking region of IGF1 and birth weight was found in the three breeds of goats. In Gulin Ma goats, two polymorphisms were found to affect litter size traits. In Chuandong White goats and Guizhou White goats, no significant difference （P0.05） in litter size between goats carrying different genotypes was observed. Further evaluation and confirmation studies in more goat populations with larger sample sizes are necessary.展开更多
In this study,the methylation-sensitive amplification polymorphism(MSAP)was used to compare the genomic DNA methylation level of muscle,gill and hepatopancreas of Portunus trituberculatus subjected to salinity 12 for ...In this study,the methylation-sensitive amplification polymorphism(MSAP)was used to compare the genomic DNA methylation level of muscle,gill and hepatopancreas of Portunus trituberculatus subjected to salinity 12 for 30 days to illustrate the epigenetic mechanism of osmoregulation.Thirty primers were used to analyze the difference of methylation level of different tissues.The results showed that the baseline methylation level of muscle,hepatopancreas and gill was 47.31%,22.94%and 17.69%,respectively.After exposed to low salinity stress,the methylation epiloci changed in the three tissues.Both demethylation and methylation processes occurred under low salinity stress.The methylation ratio decreased in muscle and gill but increased in hepatopancreas.These results indicated that DNA methylation is tissue-specific when P.trituberculatus responds to low salinity.展开更多
The relationship between microsatellite polymorphism and body weight of captive bred Chinese sea cucumber Apostichopus japonicus was investigated in two local populations in Dalian. Among ten loci discovered, nine sho...The relationship between microsatellite polymorphism and body weight of captive bred Chinese sea cucumber Apostichopus japonicus was investigated in two local populations in Dalian. Among ten loci discovered, nine show changes except for AJ07 loci. Seven loci were found highly polymorphic in both populations. For each locus in two populations, the average number of alleles is 6.428 6 and 6.285 7, the average observed heterozygosity at 0.225 7 and 0.245 9, the expected heterozygosity at 0.776 8 and 0.748 8, the polymorphism information content (PIC) at 0.709 2 and 0.674 6, respectively. Further analysis show significant correlation between A. japonicus body weight and occurrence markers AJ02 and AJ04. The findings of the relation may be helpful for molecular breeding, as well as the marker-assisted selection of sea cucumbers.展开更多
Objective： Aflatoxin B1 （AFB1）, which can cause the formation of AFB1-DNA adducts, is a known human carcinogen. AFB1-exposure individuals with inherited susceptible carcinogen-metabolizing or repairing genotypes ma...Objective： Aflatoxin B1 （AFB1）, which can cause the formation of AFB1-DNA adducts, is a known human carcinogen. AFB1-exposure individuals with inherited susceptible carcinogen-metabolizing or repairing genotypes may experience an increased risk of genotoxicity. This study was designed to investigate whether the polymorphisms of two genes, the metabolic gene Glutathione S-transferase M1 （GSTM1） and DNA repair gene x-ray repair cross-complementing group 3 （XRCC3）, can affect the levels of AFB1-DNA adducts in Guangxi Population （n= 966） from an AFB1-exposure area. Methods： AFB1-DNA adducts were measured by ELISA, and GSTM1 and XRCC3 codon 241 genotypes were identified by PCR-RFLP. Results： The GSTM1-null genotype [adjusted odds ratio （OR） = 2.09; 95% confidence interval （CI） = 1.61-2.71] and XRCC3 genotypes with 241 Met alleles [i.e., XRCC3-TM and -MM, adjusted ORs （95% CI） were 1.43 （1.08-1.89） and 2.42 （1.13-5.22）, respectively] were significantly associated with higher levels of AFB1-DNA adducts. Compared with those individuals who did not express any putative risk genotypes as reference （OR = 1）, individuals featuring all of the putative risk genotypes did experience a significantly higher DNA-adduct levels （adjusted ORs were 2.87 for GSTM1-null and XRCC3-TM; 5.83 for GSTM1-null and XRCC3-MM）. Additionally, there was a positive joint effect between XRCC3 genotypes and long-term AFB1 exposure in the formation of AFB1-DNA adducts. Conclusion： These results suggest that individuals with susceptible genotypes GSTM1-null, XRCC3-TM, or XRCC3-MM may experience an increased risk of DNA damage elicited by AFB1 exposure.展开更多
Forecast of the heterosis of Small Tail Han sheep crossed with imported meat sheep by genetic polymorphism of microsatellite DNA was done in different sheep breeds. The gene frequency, the polymorphism information con...Forecast of the heterosis of Small Tail Han sheep crossed with imported meat sheep by genetic polymorphism of microsatellite DNA was done in different sheep breeds. The gene frequency, the polymorphism information contents, the number of effective alleles, the heterozygosity, and the genetic distances were studied in four imported meat sheep and Small Tail Han sheep using five microsatellite loci. The crossing effects on the Small Tail Han sheep with four imported meat sheep were tested. The results indicate that there are genetic polymorphisms at five microsatellite loci in five sheep breeds. Five microsatellite loci can be used for genetic diversity evaluation in sheep breeds. The genetic variability of Dorset is the highest, and that of the Small Tail Han sheep is the lowest in the five sheep breeds. The order of heterosis from large to small in four imported meat sheep by the analysis of genetic relationship is White-Suffolk, Black-Suffolk, Dorset, and Texel. This accords with the testing results of actual heterosis. It is feasible to forecast the heterosis of Small Tail Han sheep crossed with imported meat sheep by genetic polymorphism of microsatellite DNA, which will have an important value for sheep breeding in the future.展开更多
AIM： To investigate the correlation between C/T single nucleotide polymorphism （SNP） in the promoter of the DNA methyltransferase 3B （D/VMT3B） gene and risk for development and progression of primary hepatocellul...AIM： To investigate the correlation between C/T single nucleotide polymorphism （SNP） in the promoter of the DNA methyltransferase 3B （D/VMT3B） gene and risk for development and progression of primary hepatocellular carcinoma （HCC）. METHODS： One hundred case subjects were selected consecutively from Tongji Hospital （Wuhan, China）. from March to November 2006. They did not receive radiotherapy or chemotherapy for newly diagnosed and histopathologically confirmed HCC. One hundred and forty control subjects having no history of cancerous or genetic diseases were healthy volunteers to Wuhan Blood Center in the same period. Frequency was matched for sex, age, alcohol consumption and cigarette smoking status of the case subjects. C/T polymorphism of the DNMT3B promoter was analyzed using polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） and sequencing analysis. The association between genotypes of DNMT3B and clinicopathological parameters among cases was also studied. RESULTS： The CC genotype HCC patients and controls. was not detected in both In control subjects, the frequency of TT and CT genotypes was 99.3% and 0.7% respectively, and that of T and C alleles was 99.6% and 0.4% respectively. The frequency of CT genotype was higher in HCC （3.0%）. The frequency of T and C alleles was 98.5% and 1.5% respectively. However, the genotype and allelotype distribution in HCC patients was not significantly different from that in controls. CONCLUSION： C/T polymorphism is not associated with the increased risk of HCC. DNMT3B genetic polymorphism is variable in different races, ethnic groups or geographic areas. Further study is needed to clarify the role of DNMT3B SNP in the development of HCCamong other populations.展开更多
Objectives: Excision repair cross-complementation group 1 (ERCC1) is a key DNA repair gene in the nucleotide excision repair pathway which is activated in the repair of intra- and interstrand DNA crosslink caused by p...Objectives: Excision repair cross-complementation group 1 (ERCC1) is a key DNA repair gene in the nucleotide excision repair pathway which is activated in the repair of intra- and interstrand DNA crosslink caused by platinum-based treatment. Two single nucleotide polymorphisms (SNPs) of the ERCC1 gene, codon 118 C/T and C8092A, have been reported to be functional, but the influence on platinum resistance and survival is not yet clear. The primary aim of the present study was to investigate whether the two SNPs were associated with resistance to standard combination carboplatin and paclitaxel chemotherapy and the potential prognostic impact in newly diagnosed ovarian cancer patients. Methods: Serum samples from 202 patients with newly diagnosed ovarian cancer were assessed for ERCC1 SNP genotyping using real time PCR. All patients were treated with first line carboplatin/paclitaxel chemotherapy. Results: There were no correlation between the ERCC1 118 C/T and C8092A genotypes and platinum resistance (P = 0.79 and P = 0.36, respectively). Furthermore, the results showed no association to progression free survival (P = 0.18 and P = 0.16, respectively) or overall survival (P = 0.89 and P = 0.78, respectively) for the two SNPs. Conclusions: The ERCC1 118 C/T and C8092A polymorphisms did not have significant influence on clinical outcome defined as platinum resistance, PFS and OS.展开更多
The DNA of P3 promoter region of IGF-Ⅱ gene was obtained by means of PCR technique. The examination of DNA polymorphism by restriction endonuclease BstE Ⅱ and the examination of AFP by bioluminescence immunoassay te...The DNA of P3 promoter region of IGF-Ⅱ gene was obtained by means of PCR technique. The examination of DNA polymorphism by restriction endonuclease BstE Ⅱ and the examination of AFP by bioluminescence immunoassay technique were carried out. The results have a significant difference( P <0.005). But the positive rate of AFP is higher than that of DNA polymorphism. The experimental result shows that the change of the DNA polymorphism of IGF-Ⅱis not the only carcinogenic factor. The suggested unite examination is the best method for the diagnosis of the primary hepatocellular carcinoma.展开更多
We analyzed the sequence alignment on 25 AA rice and 24 non-AA rice chloroplasts using two length diversity markers (ORF 100 and ORF29-TrnCGCA) and four sequence markers existed in introns of rps16 gene and TrnTUGU-Tr...We analyzed the sequence alignment on 25 AA rice and 24 non-AA rice chloroplasts using two length diversity markers (ORF 100 and ORF29-TrnCGCA) and four sequence markers existed in introns of rps16 gene and TrnTUGU-TrnLUAA spacer to explore the chloroplast diversity of different types of rice using PCR amplification and sequencing. Results showed that in terms of the length of ORF100 and ORF29-TrnCGCA, chloroplast DNA (cp DNA) of Hainan ordinary wild rice, Dongxiang ordinary wild rice, Hepu ordinary wild rice and three-line cytoplasmic male sterile wild rice were indica-type, Chaling ordinary wild rice, Fusui ordinary wild rice, Niwara wild rice, Brazilian upland rice and Lemont were japonica-type among in AA genome. Besides, all non-AA wild rice was japonica-type. There were 4 indica-japonica markers utilizing introns of rps16 gene and TrnTUGU-TrnLUAA. We found that all the ordinary wild rice in Chaling and Fusui of AA genome presented as japonica specific sites, while the others owned two indica and japonica specific sites, respectively. There were two indica-japonica sites separately and a 6-base specific fragment in three-line cytoplasmic male sterile materials except Yuetai A, simultaneously, 2-base difference from Hainan wild rice. Moreover, Brazilian upland rice and Lemont were entire japonica specific sites. Result of three markers indicated that the cp DNA of non-AA wild rice was japonica-type and result of one marker showed indica-type. Sequencing results also suggested that wild rice existed many polymorphic base sites, CCDD genome, wart wild rice and malay wild rice had their own specific sites. In conclusion, significant differentiation trend of indica-japonica exhibits in chloroplast of ordinary wild rice, and non-AA wild rice is generally japonica-type. The cytoplasmic polymorphism level of three-line sterile lines is low. It is worth considering whether the cytoplasm of Honglian-type sterile line Yuetai A comes from Hainan ordinary wild rice. Furthermore, genetic polymorphisms in wild rice are far more than in cultivar.展开更多
文摘[Objective] The study aimed to investigate the genetic polymorphism of eighteen Lycium barbarum resources via nrDNA ITS sequencing. [Method] The genomic DNAs from Lycium barbarum leaves were isolated by modified CTAB method for PCR amplification on the nrDNA ITS region using specifically synthesized primers; the amplified fragments were cloned and sequenced, then the sequencing results were clustered. [Result] nrDNA ITS sequences of the tested eighteen Lycium barbarum were firstly obtained in the present study. For all eighteen tested materials, the variation range of whole ITS region was 559-634 bp, with an average of 612 bp; alignment analyses showed that the whole length of internal transcribed spacer (ITS1+ITS2) was 480 bp, within which there are 194 variation sites (accounting for 40.4%) and 286 conserved sites (accounting for 59.6%). The cluster results showed that the eighteen tested materials could be grouped into three classes. [Conclusion] Analysis of nrDNA ITS sequence may avail to identify the Lycium barbarum germplasm resources.
基金This work was supported by the National Natural Science Foundation of China (No. 39560035).
文摘To reveal the genetic structures and relationships of the four ethnic populations from the maternal inheritance and explore the origins and migrations of nationalities, the genetic polymorphism of mtDNA in Dong, Gelao, Tujia, and Yi populations from Guizhou was studied by direct sequencing of hypervariable segment Ⅰ （HVS Ⅰ ） and PCR-RFLP of coding region. Thirty-seven （sub-） haplogroups were identified in the classification tree of mtDNA haplogroups. Haplogroup distributions and principal component （PC） analysis showed that the Dong has high frequencies of south-prevalent haplogroups, which indicates that it is a typically southern population. The Yi harbors high frequencies of the south-prevalent and northern-prevalent haplogroups, which demonstrates that it inherits the maternal characteristics from both southern and northern populations. The Yi and Gelao cluster together, the reason for which might be that their ancestries frequently underwent gene exchanges and mixtures.
基金Supported by Basic Scientific Research Fund Project of Nonprofit Research Institutions(Grassland Research Institute,Chinese Academy of Agricultural Sciences)~~
文摘[ Objective] The relationship between the genetic evolution and phylogenesis of the main grasshopper species in Inner Mongolia grasslands in molecular level was studied. [ Method] Random amplified polymorphic DNA （RAPD） technique was used to amplify the 80 individuals of 8 grasshoppers （4 families, 6 genera） in Acridoidea, the polymorphisms of their genomic DNA were compared. [ Result] 64 specific fragments were amplified by 7 primers with the molecular weight of 300 -2 000 bp. The genetic distance between 8 grasshoppers was 0.228 2 -0.589 6. Band pat- tern showed that polymorphism was commonly existed in different genus within the same family and different species within the same genus. The resuits were conducted UPGMA cluster analysis according to Neis＇ genetic distance, the results showed that the species within the same genus first clustered together, then the species in the same family clustered together. [ Condusloa] The study could provide molecular biological basis for system development and evolution research of main grasshoppers in Inner Mongolia grassland.
基金This study was supported by a grant from National Natural Science Foundation of China (No. 30100147).
文摘Objective To compare the asbestos-induced DNA damage and repair capacities of DNA damage between 104 asbestosexposed workers and 101 control workers in Qingdao City of China and to investigate the possible association between polymorphisms in codon 399 of XRCC1 and susceptibility to asbestosis. Methods DNA damage levels in peripheral blood lymphocytes were determined by comet assay, and XRCC1 genetic polymorphisms of DNA samples from 51 asbestosis cases and 53 non-asbestosis workers with a similar asbestos exposure history were analyzed by PCR/RFLP. Results The basal comet scores （3.95±2.95） were significantly higher in asbestos-exposed workers than in control workers （0.10±0.28）. After 1 h H2O2 stimulation, DNA damage of lymphocytes exhibited different increases. After a 4 h repair period, the comet scores were 50.98±19.53 in asbestos-exposed workers and 18.32±12.04 in controls. The residual DNA damage （RD） was significantly greater （P〈0.01） in asbestos-exposed workers （35.62%） than in controls （27.75%）. XRCC1 genetic polymorphism in 104 asbestos-exposed workers was not associated with increased risk of asbestosis. But compared with polymorphisms in the DNA repair gene XRCC1 （polymorphisms in codon 399） and the DNA damage induced by asbestos, the comet scores in asbestosis cases with Gin/Gin, Gln/Arg, and Arg/Arg were 40.26±18.94, 38.03±28.22, and 32.01±11.65, respectively, which were higher than those in non-asbestosis workers with the same genotypes （25.58±11.08, 37.08±14.74, and 29.38±10.15）. There were significant differences in the comet scores between asbestosis cases and non-asbestosis workers with Gin/Gin by Student＇s t-test （P〈0.05 or 0.01）. The comet scores were higher in asbestosis workers with Gin/Gin than in those with Arg/Arg and in non-asbestosis workers exposed to asbestos, but without statistically significant difference. Conclusions Exposure to asbestos may be related to DNA damage or the capacity of cells to repair H2O2-induced DNA damage. DNA repair gene XRCC 1 codon 399 may be responsible for the inter-individual susceptibility in DNA damage and repair capacities.
文摘The chromosomal localization of 45S ribosomal RNA genes in Ambystoma jeffersonianum was determined by fluorescence in situ hybridization with 18S rDNA fragment as a probe (FISH-rDNA). Our results revealed the presence of rDNA polymorphism among A.jeffersonianum populations in terms of number,location and FISH signal intensity on the chromosomes. Nine rDNA cytotypes were found in ten geographically isolated populations and most of them contained derivative rDNA sites. Our preliminary study provides strong indication of karyotypic diversification of A.jeffersonianum that is demonstrated by intraspecific variation of 45S rDNA cytotypes. rDNA cytotype polymorphism has been described in many other caudate amphibians. We predict that habitat isolation,low dispersal ability and decline of effective population size could facilitate the fixation and accumulation of variable rDNA cytotypes during their chromosome evolution.
基金the National Science Foundation of China (Grant Nos. 30771747 and 30640036)the Beijing Natural Science Foundation (No. 6042020)+1 种基金the research projects supported by the Hebei Education Department (No. Z2010102)the Baoding University (No. 2010Z02)
文摘The chloroplast DNA （cpDNA） and mitochondrial DNA （mtDNA） of 16 Populus species （Section Leuce） and their F1 generation were detected using PCR-RFLP technique. The results show that cpDNA in the F1 generation of 22 hybrid combinations was inherited maternally, which supported the conclusions of the study of plasmid cytology. The mtDNA fragments amplified by PCR were consistent with the restriction maps in all hybrid combinations and no polymorphism was detected, indicating that the Section Leuce is highly conserved in mitochondrial gene sequences. These results provided direct evidence of maternal chloroplast inheritance in Populus tomentosa, P. bolleana, P. davidiana, P. adenopoda, P. tomentosa × P. bolleana, P. alba × P. glandulosa and P. alba × P. tomentosa.
基金Supported by the State Scientific Basic Research Platform Program( No. 2005DKA21101)China Postdoctoral Science Foundation(No. 20080430470)+7 种基金Natural Science Foundation of Jiangsu Prov-ince of China (BK2007556)the National high-tech R&D program(863 program)(No.2006AA10Z198)Key Projects in the NationalScience &Technology Pillar Program during the Eleventh Five-Year Plan Period(No.2006BAD13B08 )Support Foundation of Chinaduring the 11th Five-Year Plan Period (No. 2008BADB2B04)BasicNatural Science Foundation for Colleges and Universities in JiangsuProvince (NK051039)Jiangsu Government Scholarship for Over-seas Studies ProjectQing Lan Project of Colleges and UniversitiesJiangsu Provincethe New Century Talent Project of Yangzhou University in China~~
文摘[ Objective ] This study was to analyze the genetic polymorphism in GDF8 Region of HU sheep. [Method] Four microsatellite loci including BMS1591, TEXAN-2, FCB128 and BM81124 mapped on GDF8 region of chromosome No. 2 of sheep that may be correlated with growth performance were chosen to detect the molecular genetics foundation of growth performance of Hu sheep. [ Result] Four microsatellite loci detected were high in heterozygosity, more in effective alleles number and rich in polymorphic information, all the three indices passed through the high polymorphic level （PIC 〉0.5）. [ Conclusion ] The four microsatellite loci detected could be used to estimate the genetic polymorphism of growth performance of Hu sheep.
文摘Ecotilling is a new approach based on enzyme-mediated heteroduplex cleavage to discover DNA polymorphisms in natural population. We used mung bean nuclease（MBN） instead of routinely used CELI to cleave single base pair mismatches in heteroduplex DNA templates. Nested set of primers were designed to amplify targeted region to avoid the influence of the variation in quality and quantity of the genomic DNA. To reduce the costs in fluorescently labeled primers, we added M13 adapter to 5＇end of gene specific primers to make IRD dye labeled M13 forward and reverse primers possibly universal for different genes. A Brassica rapa ZIP gene homologue was subjected to the analysis to practise the feasibility of the method in polymorphisms detection. Our experiment showed this method is efficient in discovering DNA polymorphisms in Brassica rapa natural population.
基金jointly supported by Chinese National Key Technology R & D Program (2015BAD15B02)National Natural Science Foundation of China (31661143002 and 31501034)
文摘Investigation of the relationships of phenotypic and epigenetic variations might he a good way to dissect the genetic or molecular basis of phenotypic variation and plasticity in plants, Castor bean （Ricinus cornraunis L）, an important non-edible oilseed crop, is a mono-species genus plant in the family Euphorbiaceae. Since it displays rich phenotypic variations with low genetic diversity, castor bean is a good model to investigate the molecular basis of phenotypic and epigenetic variations. Cytosine DNA methylation represents a major molecular mechanism of epigenetic occurrence. In this study, epigenetic diversity of sixty landrace accessions collected worldwide was investigated using the methylation- sensitive amplification polymorphism （MSAP） technique, Results showed that the epigenetic diversity （based on the polymorphism of DNA methylated loci） exhibited a medium variation （Ne = 1.395, He = 0.242, I = 0.366） at the population level though the variation was great, ranging from 3,80% to 3431% among accessions. Both population structure analysis and the phylogenetic construction （using the neighbor-joining criteria） revealed that the two main clades were identified, but they did not display a distinct geographic structure, After inspecting the location of polymorphic methylated loci on genome we identified that the polymorphic methylated loci occur widely in nuclear and organelle genomes. This study provides new data to understand phenotypic and epigenetic variations in castor bean,
基金Supported by the National Natural Science Foundation of China,No.30371591the Natural Science Foundation of Hebei Province,No.C20040062
文摘AIM:To investigate the association between single nucleotide polymorphism (SNP) in promoter of the DNA methyltrans-ferase 3B(DNMT3B) gene and risk for development and lymphatic metastasis of gastric cardiac adenocarcinoma (GCA). METHODS: The hospital based case-control study included 212 GCA patients and 294 control subjects without overt cancer. The DNMT3B SNP was genotyped by PCR and restriction fragment length polymorphism (RFLP) analysis. RESULTS: The C/C genotype was not detected in both GCA patients and controls. In control subjects, the frequency of T/T and C/T genotypes was 94.9% and 5.1% respectively, and that of T and C alleles was 97.4% and 2.6%, respectively. The genotype and allelotype distribution in the GCA patients was not significantly different from that in controls (P=0.34 and 0.33, respectively). When stratified by smoking status and family history of upper gastrointestinal cancer, significant difference in the genotype distribution was not observed between GCA patients and controls. The distribution of DNMT3B genotypes in GCA patents with or without lymphatic metastasis did not show significant difference (P= 0.42). CONCLUSION: The distribution of DNMT3B SNP in North China is distinct from that in Caucasians. Although this SNP has been associated with susceptibility to lung, head, neck and breast cancer, it may not be used as a stratification marker to predict susceptibility and lymphatic metastasis of GCA, at least in the population of North China.
基金supported by the earmarked fund for Modern Agro-Industry Technology Research System of China (nycytx-39)the Natural Science Foundation Project of CQ CSTC, Chongqing City, China (CSTC, 2009BA1066)
文摘Research on the identity of genes and their relationship with traits of economic importance in farm animals could assist in the selection of livestock. In this study, the polymorphisms of insulin-like growth factor 1 （IGF1） gene in 561 goats of ten breeds were detected by polymerase chain reaction （PCR）-single strand conformation polymorphism （SSCP） and their association with litter size and birth weight in three breeds were investigated. The effects of IGF1 polymorphisms on the breeding value for litter size and birth weight were examined using least square methods. Two deletions （CA） were detected in the microsatellite and two mutations （A1637G, T1640C） were found in 5′-flanking regulatory region. No significant association between the polymorphisms in 5′-flanking region of IGF1 and birth weight was found in the three breeds of goats. In Gulin Ma goats, two polymorphisms were found to affect litter size traits. In Chuandong White goats and Guizhou White goats, no significant difference （P0.05） in litter size between goats carrying different genotypes was observed. Further evaluation and confirmation studies in more goat populations with larger sample sizes are necessary.
基金supported by the grants from the National Natural Science Foundation of China (No. 4147 6124)the Natural Science Foundation of Zhejiang Province (No. LY17C190005)+3 种基金the Major Agriculture Program of Ningbo (No. 2017C110007)the Ningbo Science and Technology Project (No. 2016C10037)the Open Fund of Ningbo University (No. xkzsc1505)K C Wong Magana Fund in Ningbo University
文摘In this study,the methylation-sensitive amplification polymorphism(MSAP)was used to compare the genomic DNA methylation level of muscle,gill and hepatopancreas of Portunus trituberculatus subjected to salinity 12 for 30 days to illustrate the epigenetic mechanism of osmoregulation.Thirty primers were used to analyze the difference of methylation level of different tissues.The results showed that the baseline methylation level of muscle,hepatopancreas and gill was 47.31%,22.94%and 17.69%,respectively.After exposed to low salinity stress,the methylation epiloci changed in the three tissues.Both demethylation and methylation processes occurred under low salinity stress.The methylation ratio decreased in muscle and gill but increased in hepatopancreas.These results indicated that DNA methylation is tissue-specific when P.trituberculatus responds to low salinity.
基金Supported by the National High Technology Research and Development Program of China (863 Program, No. 2006AA10A411)the Natural Science Foundation of Liaoning Province (No.20072139)the Grant of Dalian Fisheries University, the Key Laboratory Foundation of the Educational Department of Liaoning Province (No.2009S024)
文摘The relationship between microsatellite polymorphism and body weight of captive bred Chinese sea cucumber Apostichopus japonicus was investigated in two local populations in Dalian. Among ten loci discovered, nine show changes except for AJ07 loci. Seven loci were found highly polymorphic in both populations. For each locus in two populations, the average number of alleles is 6.428 6 and 6.285 7, the average observed heterozygosity at 0.225 7 and 0.245 9, the expected heterozygosity at 0.776 8 and 0.748 8, the polymorphism information content (PIC) at 0.709 2 and 0.674 6, respectively. Further analysis show significant correlation between A. japonicus body weight and occurrence markers AJ02 and AJ04. The findings of the relation may be helpful for molecular breeding, as well as the marker-assisted selection of sea cucumbers.
基金supported by the National Natural Science Foundation of China (No.39860032)the Youth Science Foundation of Guangxi (No.0833097)
文摘Objective： Aflatoxin B1 （AFB1）, which can cause the formation of AFB1-DNA adducts, is a known human carcinogen. AFB1-exposure individuals with inherited susceptible carcinogen-metabolizing or repairing genotypes may experience an increased risk of genotoxicity. This study was designed to investigate whether the polymorphisms of two genes, the metabolic gene Glutathione S-transferase M1 （GSTM1） and DNA repair gene x-ray repair cross-complementing group 3 （XRCC3）, can affect the levels of AFB1-DNA adducts in Guangxi Population （n= 966） from an AFB1-exposure area. Methods： AFB1-DNA adducts were measured by ELISA, and GSTM1 and XRCC3 codon 241 genotypes were identified by PCR-RFLP. Results： The GSTM1-null genotype [adjusted odds ratio （OR） = 2.09; 95% confidence interval （CI） = 1.61-2.71] and XRCC3 genotypes with 241 Met alleles [i.e., XRCC3-TM and -MM, adjusted ORs （95% CI） were 1.43 （1.08-1.89） and 2.42 （1.13-5.22）, respectively] were significantly associated with higher levels of AFB1-DNA adducts. Compared with those individuals who did not express any putative risk genotypes as reference （OR = 1）, individuals featuring all of the putative risk genotypes did experience a significantly higher DNA-adduct levels （adjusted ORs were 2.87 for GSTM1-null and XRCC3-TM; 5.83 for GSTM1-null and XRCC3-MM）. Additionally, there was a positive joint effect between XRCC3 genotypes and long-term AFB1 exposure in the formation of AFB1-DNA adducts. Conclusion： These results suggest that individuals with susceptible genotypes GSTM1-null, XRCC3-TM, or XRCC3-MM may experience an increased risk of DNA damage elicited by AFB1 exposure.
文摘Forecast of the heterosis of Small Tail Han sheep crossed with imported meat sheep by genetic polymorphism of microsatellite DNA was done in different sheep breeds. The gene frequency, the polymorphism information contents, the number of effective alleles, the heterozygosity, and the genetic distances were studied in four imported meat sheep and Small Tail Han sheep using five microsatellite loci. The crossing effects on the Small Tail Han sheep with four imported meat sheep were tested. The results indicate that there are genetic polymorphisms at five microsatellite loci in five sheep breeds. Five microsatellite loci can be used for genetic diversity evaluation in sheep breeds. The genetic variability of Dorset is the highest, and that of the Small Tail Han sheep is the lowest in the five sheep breeds. The order of heterosis from large to small in four imported meat sheep by the analysis of genetic relationship is White-Suffolk, Black-Suffolk, Dorset, and Texel. This accords with the testing results of actual heterosis. It is feasible to forecast the heterosis of Small Tail Han sheep crossed with imported meat sheep by genetic polymorphism of microsatellite DNA, which will have an important value for sheep breeding in the future.
文摘AIM： To investigate the correlation between C/T single nucleotide polymorphism （SNP） in the promoter of the DNA methyltransferase 3B （D/VMT3B） gene and risk for development and progression of primary hepatocellular carcinoma （HCC）. METHODS： One hundred case subjects were selected consecutively from Tongji Hospital （Wuhan, China）. from March to November 2006. They did not receive radiotherapy or chemotherapy for newly diagnosed and histopathologically confirmed HCC. One hundred and forty control subjects having no history of cancerous or genetic diseases were healthy volunteers to Wuhan Blood Center in the same period. Frequency was matched for sex, age, alcohol consumption and cigarette smoking status of the case subjects. C/T polymorphism of the DNMT3B promoter was analyzed using polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） and sequencing analysis. The association between genotypes of DNMT3B and clinicopathological parameters among cases was also studied. RESULTS： The CC genotype HCC patients and controls. was not detected in both In control subjects, the frequency of TT and CT genotypes was 99.3% and 0.7% respectively, and that of T and C alleles was 99.6% and 0.4% respectively. The frequency of CT genotype was higher in HCC （3.0%）. The frequency of T and C alleles was 98.5% and 1.5% respectively. However, the genotype and allelotype distribution in HCC patients was not significantly different from that in controls. CONCLUSION： C/T polymorphism is not associated with the increased risk of HCC. DNMT3B genetic polymorphism is variable in different races, ethnic groups or geographic areas. Further study is needed to clarify the role of DNMT3B SNP in the development of HCCamong other populations.
文摘Objectives: Excision repair cross-complementation group 1 (ERCC1) is a key DNA repair gene in the nucleotide excision repair pathway which is activated in the repair of intra- and interstrand DNA crosslink caused by platinum-based treatment. Two single nucleotide polymorphisms (SNPs) of the ERCC1 gene, codon 118 C/T and C8092A, have been reported to be functional, but the influence on platinum resistance and survival is not yet clear. The primary aim of the present study was to investigate whether the two SNPs were associated with resistance to standard combination carboplatin and paclitaxel chemotherapy and the potential prognostic impact in newly diagnosed ovarian cancer patients. Methods: Serum samples from 202 patients with newly diagnosed ovarian cancer were assessed for ERCC1 SNP genotyping using real time PCR. All patients were treated with first line carboplatin/paclitaxel chemotherapy. Results: There were no correlation between the ERCC1 118 C/T and C8092A genotypes and platinum resistance (P = 0.79 and P = 0.36, respectively). Furthermore, the results showed no association to progression free survival (P = 0.18 and P = 0.16, respectively) or overall survival (P = 0.89 and P = 0.78, respectively) for the two SNPs. Conclusions: The ERCC1 118 C/T and C8092A polymorphisms did not have significant influence on clinical outcome defined as platinum resistance, PFS and OS.
文摘The DNA of P3 promoter region of IGF-Ⅱ gene was obtained by means of PCR technique. The examination of DNA polymorphism by restriction endonuclease BstE Ⅱ and the examination of AFP by bioluminescence immunoassay technique were carried out. The results have a significant difference( P <0.005). But the positive rate of AFP is higher than that of DNA polymorphism. The experimental result shows that the change of the DNA polymorphism of IGF-Ⅱis not the only carcinogenic factor. The suggested unite examination is the best method for the diagnosis of the primary hepatocellular carcinoma.
文摘We analyzed the sequence alignment on 25 AA rice and 24 non-AA rice chloroplasts using two length diversity markers (ORF 100 and ORF29-TrnCGCA) and four sequence markers existed in introns of rps16 gene and TrnTUGU-TrnLUAA spacer to explore the chloroplast diversity of different types of rice using PCR amplification and sequencing. Results showed that in terms of the length of ORF100 and ORF29-TrnCGCA, chloroplast DNA (cp DNA) of Hainan ordinary wild rice, Dongxiang ordinary wild rice, Hepu ordinary wild rice and three-line cytoplasmic male sterile wild rice were indica-type, Chaling ordinary wild rice, Fusui ordinary wild rice, Niwara wild rice, Brazilian upland rice and Lemont were japonica-type among in AA genome. Besides, all non-AA wild rice was japonica-type. There were 4 indica-japonica markers utilizing introns of rps16 gene and TrnTUGU-TrnLUAA. We found that all the ordinary wild rice in Chaling and Fusui of AA genome presented as japonica specific sites, while the others owned two indica and japonica specific sites, respectively. There were two indica-japonica sites separately and a 6-base specific fragment in three-line cytoplasmic male sterile materials except Yuetai A, simultaneously, 2-base difference from Hainan wild rice. Moreover, Brazilian upland rice and Lemont were entire japonica specific sites. Result of three markers indicated that the cp DNA of non-AA wild rice was japonica-type and result of one marker showed indica-type. Sequencing results also suggested that wild rice existed many polymorphic base sites, CCDD genome, wart wild rice and malay wild rice had their own specific sites. In conclusion, significant differentiation trend of indica-japonica exhibits in chloroplast of ordinary wild rice, and non-AA wild rice is generally japonica-type. The cytoplasmic polymorphism level of three-line sterile lines is low. It is worth considering whether the cytoplasm of Honglian-type sterile line Yuetai A comes from Hainan ordinary wild rice. Furthermore, genetic polymorphisms in wild rice are far more than in cultivar.
