古丈县南方红豆杉天然群体的遗传多样性研究

通过对分布于湖南省古丈县的南方红豆杉(Taxus chinensis)天然群体中30个个体的功能叶片的过氧化物酶(POD)和酯酶(EST)同工酶谱带的分析,研究了该天然群体的遗传多样性水平.结果表明:30个个体中都存在有迁移率相同的谱带(4条),占酶谱带总数的26.7%;两个酶系统共检出15条酶谱带,等位基因位点数4个,其中多态位点数3个,单态位点数1个,多态位点百分数P=75%,平均每个位点的等住基因数A=3,平均有效等位基因数Ae=2.75,平均期望杂合度He=60.7%,平均实际杂合度Ho=22.2%,表明该群体有较丰富的遗传多样性.     

鳜原种群体和养殖群体遗传多样性的微卫星分析

本研究利用20对微卫星引物对鳜(Siniperca chuatsi)原种群体和养殖群体进行遗传多样性分析。结果表明,在鳜原种群体中检测到多态性位点14个,养殖群体11个。在两个群体中共检测到等位基因数96个,其中原种群体检测到等位基因数53个,每个位点的等位基因数在1～7之间,平均有效等位基因数为2.7390;养殖群体检测到等位基因数43个,每个位点的等位基因数在1～6之间,平均有效等位基因数为2.1284。原种群体的平均观察杂合度0.5708,Nei氏期望杂合度0.5295,平均多态信息含量PIC0.5353;养殖群体的平均观察杂合度0.3839,Nei氏期望杂合度0.4011,平均多态信息含量PIC0.5043。因此,与养殖群体相比,鳜原种群体仍有丰富的遗传多样性。本研究可为鳜种质资源的保护、监测和遗传育种提供分子水平上的数据。     

长江中上游两个鲢群体遗传变异的微卫星分析

对长江中上游2个鲢群体使用39个微卫星标记进行了遗传多样性分析, 计算并统计了平均观测等位基因数、平均有效等位基因数、多态信息含量、遗传杂合度、Hardy-Weinberg平衡偏离指数、遗传相似系数、遗传距离等遗传参数。结果表明: 万州鲢和监利鲢群体所检测微卫星位点的平均观测等位基因数分别为6.128和4.974; 平均有效等位基因数分别为4.107和3.395; 多态位点百分率分别为100和94.87; 39个微卫星标记共有等位基因259个, 173个等位基因为两群体所共有; 多态微卫星位点的PIC在0.077~0.865之间变动,平均为0.617; 两群体所检测位点平均观测杂合度为0.834和0.775, 平均期望杂合度为0.713和0.623; 两个群体间的遗传相似系数为0.618, 群体间的遗传距离为0.482。结果显示长江中上游两个鲢群体间存在显著遗传分化, 应隶属于不同的种群。     

罗氏沼虾转录组SSR标记筛选及其与体质量相关性分析

研究通过转录组测序对罗氏沼虾(Macrobrachium rosenbergii)SSR标记进行了发掘,获得SSR位点18592个。随机选取了63个SSR位点设计引物并利用10个个体进行多态性位点筛选,共获得31个具有多态的SSR标记,利用其中19个SSR标记对全同胞家系群(FS)119尾虾及孟加拉F3代野生群(MJL)199尾虾的群体遗传多样性进行分析,并对SSR位点与体质量性状进行关联性分析。结果表明:FS群体共检测到40个等位基因,平均等位基因数为2.1053,平均观测杂合度0.4525,平均期望杂合度0.3804,平均多态信息含量0.3076,处于中度遗传多态水平; MJL群体共检测到65个等位基因,平均等位基因数为3.4211,平均观测杂合度0.4105,平均期望杂合度0.4496,平均多态信息含量0.3882,处于中度遗传多态水平。19个SSR位点与FS群体体质量没有相关性(P>0.05),而在MJL群体中, 4个SSR位点与体质量显著相关(P<0.05)。对差异显著的位点进行不同基因型体质量性状的多重比较, MR28位点277/285基因型体质量均值极显著高于...     

大口黑鲈生长性状的微卫星DNA标记筛选

本研究在人工养殖的大口黑鲈（Micropterus salmoides L.）群体中对40个微卫星位点进行扩增, 运用卡方检验分析微卫星位点在极端大个体组和极端小个体组中的基因型分布差异, 选择差异显著的16个微卫星位点对大口黑鲈随机群体进行基因型与性状的关联分析, 同时分析群体的遗传多样性。结果表明: 关联分析得到7个微卫星位点(JZL60、JZL67、JZL72、JZL124、MiSaTPW76、MiSaTPW117和MiSaTPW173)与体重、体长和体高显著或极显著相关(P<0.05或P<0.01), 同时对差异显著的位点进行不同基因型间与生长性状的多重比较, 找到了与体重、体长和体高性状相关的最有利基因型为JZL60位点的AA、JZL67位点的BB、JZL72位点的AC、MiSaTPW76位点的BB和MiSaTPW117位点的BC。应用这16个微卫星位点对随机群体进行遗传多样性分析, 共检测到47个等位基因,平均等位基因2.938个,每个位点检测到的等位基因数为2~5个、群体的平均观测杂合度、平均期望杂合度和平均多态信息含量分别为0.515、0.500和0.445, 表明该群体遗传多样性处于中等水平。     

翘嘴红鲌苏州和宜兴养殖种群的遗传多样性分析

目的:对翘嘴红鲌养殖种群遗传多样性进行分析,以科学地评价它们的种群遗传结构。方法:采用RAPD技术,对翘嘴红鲌苏州和宜兴养殖种群的遗传多样性进行分析。结果:苏州养殖种群的多态位点比例为25%,种群平均杂合度为0.1654,Shannon多样性指数为0.671;宜兴群体的多态位点比例为22.4%,群体平均杂合度为0.1446,Shannon多样性指数为0.0594。苏州群体内各个体之间的遗传相似度度为0.9378,遗传距离为0.0622;宜兴群体内各个体之间的遗传相似度度为0.9444,遗传距离为0.0556;两群体之间的遗传距离为0.0146。结论:两种群具有较低的遗传多样性。     

三个野生群体日本囊对虾遗传多样性的SSR分析

为了解野生种群日本囊对虾遗传分化和改良遗传育种,用SSR技术对福建厦门(XM)、广东湛江(ZJ)、广西北海(BH)3个地区野生日本囊对虾进行遗传多样性的研究。采用了10对微卫星引物对3个野生种群进行分析,10个微卫星位点在3个种群中均表现为高度的多态性,每个位点平均检测到3.87个等位基因;平均多态信息含量为0.5893;3个群体的观测杂合度分别为0.6243、0.5704、0.4661,全部群体观测杂合度平均为0.5536;期望杂合度分别为0.7193、0.6189、0.6226,全部群体平均期望杂合度为0.6536。这说明3个野生种群在10个微卫星位点上均具有丰富的遗传多样性。基于Nei's遗传距离的聚类分析显示厦门群体和湛江群体的遗传距离较近。     

神农架川金丝猴人工补食群的遗传多样性和亲缘关系

以湖北神农架国家级自然保护区的川金丝猴人工补食群体为研究对象,利用微卫星遗传标记对该群体的遗传多样性和亲缘关系进行研究,并对其种群的遗传多样性发展趋势进行了预测。结果显示,12个微卫星位点在该补食群体中共检测到50个等位基因,平均观察杂合度和平均期望杂合度分别为0.668和0.630,多态信息含量为0.442-0.696,平均0.567。亲权鉴定中共鉴定出11个父-母-子单元,各单元未有近亲繁殖的状况。亲缘系数结果显示具有亲缘关系的个体对达21.64%,群体平均亲缘系数为0.1108,现6个家庭单元中有两对候选亲本具有亲缘关系,表明该群体存在较高的近交风险。遗传多样性变化趋势的模拟结果表明,种群的数量对遗传多样性的影响比较大,群体中雄雌比例也对遗传多样性的损失有影响;为避免近亲交配,保持群体的遗传多样性水平,建议进一步做好人工补食群金丝猴的个体识别,完善家庭系谱,明确繁殖个体的遗传背景;引入一批有效的建群者来增加种群的数量及优化雄雌的比例。     

利用17个微卫星标记分析鳙鱼的遗传多样性

选用本实验室克隆的17个鳙鱼微卫星分子标记分析四川泸州和江西鄱阳湖的两个种群鳙鱼的遗传多样性及种质特性,计算和统计了杂合度、多态信息含量（PIC）、有效等位基因数、等位基因频率、遗传距离、遗传相似系数、Hardy-Weinberg平衡偏离指数等方面内容。结果表明：选择使用17个微卫星标记,其中有4个为单态标记,13个为多态标记。江西和四川鳙鱼群体每个微卫星位点的平均等位基因数分别为3.325及3.882,平均有效等位基因数分别为3.531及2.676,多态位点百分率分别为82.4及70.5, 17个微卫星标记共有等位基因71个,多态微卫星位点的PIC在0.114~0.960之间变动,平均为0.417 ,两群体位点平均观测杂合度为0.385和0.452,平均期望杂合度为0.360和0.422,两个群体间的遗传相似系数为0.897,群体间的遗传距离为0.109。     

天鹅洲迁地保护江豚群体的遗传评估与发展预测

文章以2008年春季遭受严重雪灾的天鹅洲白鱀豚国家级自然保护区迁地保护江豚群体为研究对象,利用物种特异性微卫星遗传标记对该群体的遗传多样性进行了评估,并通过软件对其发展趋势进行了模拟和预测。研究结果表明,虽然2008年春季雪灾并未导致该群体遗传多样性的严重损失,灾后群体依然表现出中等水平的微卫星遗传多样性(18个座位的平均等位基因数为4.780,平均观察杂合度和期望杂合度分别为0.748和0.674);但模拟结果显示,该迁地保护江豚群体的遗传多样性将快速下降,100年后仅能保留约79%的等位基因和约84%的遗传杂合度。此外,模拟结果表明,通过增加群体数量和调整群体性比可有效减缓该群体遗传多样性的下降速度。根据研究结果,并结合长江江豚自然种群快速下降的现状,作者提出天鹅洲迁地保护江豚群体当前最重要的保护策略应该是尽早补充一定数量的、合适的野生个体,在加强遗传多样性保护的同时使其群体数量快速增长并形成一个更大规模的有效繁殖群体。     

Genetic diversity and bottleneck analysis of Nagpuri buffalo breed of India based on microsatellite data

In this study, 25 heterologous bovine microsatellite markers have been used for the assessment of genetic diversity in Nagpuri buffalo, an important breed of Central India. For this, 48 DNA samples of unrelated individuals of Nagpuri buffalo were PCR amplified and microsatellite alleles were resolved in 6% denaturing, silver stained Urea-PAGE gel. Genotypic status of individuals at each locus was identified manually and data analysis carried out using POPGENE software. Observed number of alleles varied from 2 (ILSTS073 locus) to 8 (HEL13 & ILSTS058 loci) with a mean of 5.24 alleles per locus. Moderate level of heterozygosity (0.45) indicated sufficient genetic diversity existing in this buffalo population. PIC values for the microsatellite loci analysed, ranged from 0.10 (ILSTS0I9 locus) to 0.81 (ILSTS058 locus) with a mean of 0.53. No shift in the frequency distribution of alleles and a normal L-shaped curve indicated non-existence of any bottleneck in Nagpuri. The study thus highlights the usefulness of heterologous bovine microsatellite markers to assess the genetic variability in buffalo breds as well. Also various diversity indices suggest sufficient genetic variability within Nagpuri buffalo that can be utilized as initial guidelines for future breeding strategies and conservation. The article is published in the original.     

Gene Diversity and Genetic Differentiation in Natural Populations of Picea koraiensis

Vertical slab polyacrylamide gel electrophoresis was used to examine inheritance of four isoenzymes in megagametophytes of Picea koraiensis. Gene diversity and genetic differentiation in four natural populations of P. koraiensis in Northeastern China were analyzed at six loci coding for four enzyme systems. The proportion of loci polymorphism in population was 0.5. The average expected heterozygosity of all samples was 0. 314, and the average observed heterozygosity of all samples was 0. 316. The average number of alleles detected per locus was 2.50. The effective number of alleles per locus was 1. 71. Measurement of gene diversity for the six loci showed a 0. 0059 significance of interpopulation differentiation. More than ninety-nine percent of the total gene diversity resided within population. The mean genetic distance over all pairs of P. koraiensis was 0. 0110.     

Genetic diversity and structure in a natural Elymus caninus population from Denmark based on microsatellite and isozyme analyses

 Genetic diversity in a natural Elymus caninus population from Denmark was assessed using isozyme and microsatellite markers. A total of 119 individuals from 46 maternal plants were assayed. Microsatellite loci are shown to display higher levels of variation than isozyme loci. The mean number of alleles per locus was 1.04 for isozymes and 1.38 for microsatellites. The percentage of polymorphic loci for isozymes and microsatellites was 4.7% and 23.6% across the maternal plant, respectively. The genetic diversity at population level was 0.1 for isozymes, and 0.63 for microsatellites. The mean genetic diversity at maternal plant level was 0.027 for isozyme loci and 0.117 for microsatellite loci. The average of total allozyme diversity (H_T) was 0.22. The average of total microsatellite diversity was 0.56. Isozyme and microsatellite variation showed the same pattern of differentiation between maternal plants. More than 75% total genetic diversity was found among maternal plants. About 25% total genetic diversity was detected within maternal plants. Ten (22.7%) maternal plants produced heterozygous offspring at allozyme loci, and 30 (68.2%) maternal plants gave heterozygous offspring at microsatellite loci. Both types of markers revealed a relatively high genetic diversity in this population. Received November 7, 2000 Accepted February 15, 2001     

利用SSR分子标记分析秦岭冷杉自然居群的遗传多样性

利用10对SSR引物对濒危植物秦岭冷杉(Abies chensiensis)6个自然居群的120个个体进行了遗传多样性研究,旨在分析秦岭冷杉6个自然居群的遗传多样性、遗传结构及基因流变化.研究结果表明,120个个体在10个位点上共检测到149个等位基因,平均每个位点的等位基因数(A)为14.9,每个位点的有效等位基因数(e)为7.7,每个位点的平均预期杂合度(He)和平均观察杂合度(Ho)分别为0.841和0.243,Shannon多样性指数(Ⅰ)为2.13,自然居群杂合性基因多样度的比率(FsT)为6.7％,居群间的基因流(Nm)为3.45.利用Mantel检测到自然居群的遗传距离与地理距离间无显著相关性(r=0.490 6,P＞0.05).秦岭冷杉自然居群的遗传多样性水平较低,遗传变异主要存在于居群内部.结合研究数据、实地调查及相关资料,推测秦岭冷杉自然居群间基因流较原来增大可能是因为居群间发生了远交衰退.     

Selection of high heterozygosity popcorn varieties in Brazil based on SSR markers

We analyzed genetic structure and diversity among eight populations of popcorn, using SSR loci as genetic markers. Our objectives were to select SSR loci that could be used to estimate genetic diversity within popcorn populations, and to analyze the genetic structure of promising populations with high levels of heterozygosity that could be used in breeding programs. Fifty-seven alleles (3.7 alleles per locus) were detected; the highest effective number of alleles (4.21) and the highest gene diversity (0.763) were found for the Umc2226 locus. A very high level of population differentiation was found (F(ST) = 0.3664), with F(ST) for each locus ranging from 0.1029 (Umc1664) to 0.6010 (Umc2350). This analysis allowed us to identify SSR loci with high levels of heterozygosity and heterozygous varieties, which could be selected for production of inbred lines and for developing new cultivars.     

Evolutionary relationships among 12 species belonging to three genera of the family Microhylidae in Papua New Guinea revealed by allozyme analysis

To elucidate the potential of electrophoretic analysis for understanding relationships among microhylid frogs in Papua New Guinea, an allozyme analysis was conducted. A total of 119 individuals from nine species of Cophixalus, two species of Sphenophryne and one species of Barygenys, all of which belong to the family Microhylidae, were studied. Fourteen enzymes extracted from skeletal muscles and livers were analyzed by starch-gel electrophoresis. These enzymes were encoded by genes at 20 loci. There were 2-15 phenotypes produced by 2-12 alleles at these loci. The mean proportion of heterozygous loci per individual, mean proportion of polymorphic loci per population, and mean number of alleles per locus in 12 species were 6.1%, 17.1% and 1.17a on average, respectively. The NJ and ML trees constructed from Nei's genetic distances showed that the genus Sphenophryne can be distinguished biochemically from Cophixalus and Barygenys, and that the species groups of Cophixalus, which are similar in external morphology, can be divided biochemically into several species.     

Microsatellites assessment of Chinese sturgeon (Acipenser sinensis Gray) genetic variability

Four microsatellites were used to examine the genetic variability of the spawning stocks of Chinese sturgeon, Acipenser sinensis, from the Yangtze River sampled over a 3‐year period (1999–2001). Within 60 individuals, a total of 28 alleles were detected over four polymorphic microsatellite loci. The number of alleles per locus ranged from 4 to 15, with an average allele number of 7. The number of genotypes per locus ranged from 6 to 41. The genetic diversity of four microsatellite loci varied from 0.34 to 0.67, with an average value of 0.54. For the four microsatellite loci, the deviation from the Hardy–Weinberg equilibrium was mainly due to null alleles. The mean number of alleles per locus and the mean heterozygosity were lower than the average values known for anadromous fishes. Fish were clustered according to their microsatellite characteristics using an unsupervised ‘Artificial Neural Networks’ method entitled ‘Self‐organizing Map’. The results revealed no significant genetic differentiation considering genetic distance among samples collected during different years. Lack of heterogeneity among different annual groups of spawning stocks was explained by the complex age structure (from 8 to 27 years for males and 12 to 35 years for females) of Chinese sturgeon, leading to formulate an hypothesis about the maintenance of genetic diversity and stability in long‐lived animals.     

Biochemical polymorphism in the red partridge (Alectoris rufa)]

Egg white proteins, hemoglobin, serum proteins and enzymes from Alectoris rufa have been examined by starch gel electrophoresis. All three genetic parameters, mean proportion of loci polymorphic per population (P), mean numbers of alleles per locus (A), and mean proportion of loci heterozygous per individual (H) are given for Alectoris rufa, and comparison were made between the proteins of the related species Coturnix coturnix japonica.     

Genic Heterozygosity and Protein Polymorphism among Local Populations of OENOTHERA BIENNIS

Twenty enzyme loci were studied in 44 Illinois populations of Oenothera biennis; four were polymorphic. Most of the variation was distributed between populations. Fifty-nine percent of the populations had one genotype, 27% two genotypes and the remaining 16% from three to five genotypes; the average was 1.50. The proportion of genetic diversity present in single populations is.38 of that present in the state. Members of single populations were uniformly heterozygous for 1 to 4 loci. The mean heterozygosity per population ranged from 0 to 20%. For Illinois populations collectively, heterozygosity averaged 4.5%. There was much gene frequency heterogeneity between populations. The true standardized genetic variance among populations for alleles at polymorphic loci varied from.40 to.78. Populations from Cook County were much more similar inter se than those downstate, had fewer genotypes and polymorphic loci, and had less heterozygosity than downstate populations. The mean normalized genetic identity among Cook County populations was.987 versus.947 for downstate populations. The mean number of genotypes per population in Cook County was 1.06 versus 2.40 in downstate populations. There was only one polymorphic locus in Cook County, VLP. The genetic structure of Oe. biennis suggests that single populations are colonized by one, or at best a few individuals. Cook County populations are judged to be less variable than downstate populations because the mean age of the populations probably is less than that of those downstate.