长江中游鲢鱼天然种群的生化遗传结构及变异

采用淀粉或聚丙烯酰胺凝胶电泳方法分析长江中游鲢鱼天然种群11种同工酶约31个基因座位的遗传变异性。在可用于种群遗传结构分析的27个座位中,有4个座位(Ldh-C,idhp-A,Est-1,-2)具有多态性。该种群的多态座位比例为14.8%,平均杂合度为0.0451。比较结果表明,鲢鱼天然种群的多态座位比例与人工繁殖种群相似。我们认为,鱼类人工繁殖种群遗传变异性的降低在很大程度上取决于人工繁殖过程中的某些不合理因素,人为地避免或限制这些因素将有利于保持鱼类人工繁殖种群的遗传变异性。       

真鲷自然群体和人工繁殖群体的遗传多样性

采用RAPD技术对真鲷野生群体及人工繁殖群体各23个个体进行了DNA多态性检测。实验选取OPK组16个10 bp随机引物用于两群体的遗传多样性分析。在野生群体和人工繁殖群体中分别获得131和123条扩增片段,两群体的多态片段比例分别为62.60%和54.47%,平均杂合度分别为0.4786和0.3633,可见真鲷野生群体及人工繁殖群体的遗传多样性较为丰富,在选择育种和遗传改良方面具有较大的潜力。人工繁殖群体的多态片段比例和平均杂合度都低于野生群体,意味着在生产过程中要采取行之有效的管理保护措施以避免或减少遗传多样性水平的降低,确保真鲷增养殖业的可持续发展。     

中华鲟天然群体蛋白质水平遗传多样性贫乏的初步证据

为阐明我国Ⅰ级珍稀水生保护动物中华鲟天然群体的遗传结构和遗传多样性特征,为其资源的监测量民保护提供科学依据,采用聚丙烯酰胺梯度凝胶电泳技术对中华鲟天然群体进行了蛋白质遗传多态性研究。共研究了１５种蛋白质,有４种蛋白无活呈活性很低,在有活性的１１种蛋白中人测得２６个座位;在２６个座位中,只有１个座位（ＭＤＨ－１）为多态座位。中华鲟多态座位比例（Ｐ）为３．９０％,遗传杂合度（Ｈ）为０．０４,均远远低于     

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。     

草鱼野生和养殖群体间遗传变异的微卫星分析

运用微卫星标记对江苏境内草鱼(Ctenopharyngodonidella)一个野生群体(邗江群体)和两个养殖群体(淡水中心群体和无锡前洲群体)遗传多样性进行了分析。在10个座位中,每个座位检测到的等位基因数2~8个。有效等位基因数、多态信息含量、期望杂合度、平均表观杂合度均以邗江草鱼野生群体最高,分别为3·9、0·5068、0·6939、0·7;无锡前洲草鱼养殖群体最低,分别为2·2、0·1796、0·5235、0·5286;淡水中心草鱼养殖群体各参数均介于两者之间,分别为3·5、0·2902、0·5418、0·5429。以上结果表明:草鱼野生群体遗传多样性更为丰富,而草鱼养殖群体存在杂合度降低,遗传多样性下降的现象。邗江草鱼野生群体与淡水中心草鱼养殖群体和无锡前洲草鱼养殖群体间遗传分化系数分别为0·219和0·246,而两个草鱼养殖群体间遗传分化系数为0·034。这表明草鱼野生群体与草鱼养殖群体间分化严重,而草鱼养殖群体间分化微弱。各座位分化程度的χ2检验结果表明,10个座位中有GM18、MFW1-1、MFW1-2三个座位群体间分化达到极显著水平,GM03-2、MFW5两个座位群体间分化差异显著,其他座位分化不显著。针对每个座位对各群体进行Hardy-Weinberg平衡检验发现:由于草鱼养殖群体在GM03-1、GM03-2、GM18三个位点杂合子缺失,草鱼野生群体在位点GM19杂合子过剩而严重偏离平衡。实验表明:近交容易引起草鱼遗传多样性下降,纯合速度加快。     

草鱼野生和养殖群体间遗传变异的微卫星分析

运用微卫星标记对江苏境内草鱼(Ctenopharyngodon idella)一个野生群体(邗江群体)和两个养殖群体(淡水中心群体和无锡前洲群体)遗传多样性进行了分析。在10个座位中，每个座位检测到的等位基因数2～8个。有效等位基因数、多态信息含量、期望杂合度、平均表观杂合度均以邗江草鱼野生群体最高，分别为3.9、0.506 8、0.693 9、0.7；无锡前洲草鱼养殖群体最低，分别为2.2、0.179 6、0.523 5、0.528 6；淡水中心草鱼养殖群体各参数均介于两者之间，分别为3.5、0.290 2、0.541 8、0.542 9。以上结果表明：草鱼野生群体遗传多样性更为丰富，而草鱼养殖群体存在杂合度降低，遗传多样性下降的现象。邗江草鱼野生群体与淡水中心草鱼养殖群体和无锡前洲草鱼养殖群体间遗传分化系数分别为0.219和0.246，而两个草鱼养殖群体间遗传分化系数为0.034。这表明草鱼野生群体与草鱼养殖群体间分化严重，而草鱼养殖群体间分化微弱。各座位分化程度的χ2检验结果表明，10个座位中有GM18、MFW1-1、MFW1-2三个座位群体间分化达到极显著水平，GM03-2、MFW5两个座位群体间分化差异显著，其他座位分化不显著。针对每个座位对各群体进行Hardy-Weinberg平衡检验发现：由于草鱼养殖群体在GM03-1、GM03-2、GM18三个位点杂合子缺失，草鱼野生群体在位点GM19杂合子过剩而严重偏离平衡。实验表明：近交容易引起草鱼遗传多样性下降，纯合速度加快。     

中华稻蝗四个种群的遗传分化

采用水平淀粉凝胶电泳技术研究中华稻蝗(Oxya chinensis)四个种群的12个基因座位,探讨其遗传分化.这四个种群分别采自内蒙古呼和浩特、山西代县、山西太原和陕西西安.Ck和Mdh-2在四个种群中均为单态,其余的基因座位至少在一个种群内有两个以上的等位基因;在Ldh和Mdh-1的等位基因频率呈现梯度分布趋势.多态基因座位百分率(P)和平均每个基因座位的等位基因数目(A)分别为58.3%-66.7%和2.2-2.8,平均杂合度为Ho=0.173-0.240.除Gpi,Hk-2,Idh,Ldh和Mdh-1在部分蝗虫种群符合Hardy-Weinberg平衡外,其余绝大多数基因座位的基因型频率显著偏离Hardy-Weinberg平衡.四个种群间FST平均值不存在显著差异(FST=0.0510,P＞0.05),结合高的Nei's遗传一致度(I＞0.97)可知,种群之间遗传分化不明显.我们认为人类的农业活动可能促进了种群间的基因交流,从而降低了分化程度[动物学报50(2)187-192,2004].     

湘西盲高原鳅群体同工酶分析

采用聚丙烯酰胺凝胶电泳(PAGE)对洞穴鱼类--湘西盲高原鳅(Triplophysa xiangxiensis)群体遗传多样性进行了研究.对其肌肉、心脏、肝脏、脑、脾脏和肾脏等6种组织中的乳酸脱氢酶(LDH)、苹果酸脱氢酶(MDH)、苹果酸酶(ME)、酯酶(EST)、醇脱氢酶(ADH)、谷氨酸脱氢酶(GDH)和葡萄糖-6-磷酸脱氢酶(G-6-PDH)等7种同工酶进行分析,检测到26个座位,其中多态座位4个(Ldh-3、Ldh-4、s-Mdh、m-Mdh),多态座位比例为15.38%,观察杂合度0.0398,预期杂合度0.0411,Hardy-Weinberg遗传偏离指数(D)为-0.0316,存在杂合子缺失.结果表明,湘西盲高原鳅群体群体遗传多样性较低,纯合度较高.     

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。     

独龙牛遗传多样性及其种群遗传结构的等位酶分析

采用水平片淀粉凝胶电泳技术,进行３０头独牛牛４１种蛋白质共计４４个遗传座位的等位酶分析,只在Ｔｒ,Ｈｐ,Ａｍｙ,Ｅｓｔ等４个座位发现多态性。每个座位等基因的平均数、多态座位百分比和平均杂合度值分别为Ａ＝１．０９０９、Ｐ＝０．０６８２和Ｈ＝０．０２６２。贡山县和福贡县独龙牛群体从酶基因的角度上看遗传多样性贫乏,可能是分别由小种群引种而来,受到瓶颈效应的作用,并伴随着创立者事件的发生。我们结合独龙牛在     

Wild and aquaculture populations of the eastern oyster compared using microsatellites

Five new microsatellite markers were developed for the eastern oyster (Crassostrea virginica), and allelic variability was compared between a wild Chesapeake Bay population (James River) and a hatchery strain (DEBY). All loci amplified readily and demonstrated allelic variability with the number of alleles ranging from 16 to 36 in the wild population and from 11 to 19 in the DEBY strain. Average observed and expected heterozygosities were estimated at 0.66 and 0.80 in the hatchery sample. The corresponding estimates were 0.91 and 0.75 in the wild sample. Results indicated lower genetic variability in the DEBY strain and significant genetic differentiation between the wild population and hatchery strain. These microsatellite loci will prove valuable for future population genetic studies and in tracking of hatchery strains used in restoration.     

New polymorphic microsatellite markers in Pacific abalone Haliotis discus hannai and their application to genetic characterization of wild and aquaculture populations

Seven new microsatellite markers were developed for the Pacific abalone (Haliotis discus hannai, Haliotidae), and allelic variability was compared between a wild population and a hatchery population in Yeosu, Korea. All loci amplified readily and demonstrated allelic variability, with the number of alleles ranging from 6 to 15 in the wild population and from 3 to 12 in farmed populations. Average observed and expected heterozygosities were estimated at 0.65 and 0.77 in the hatchery samples, and 0.79 and 0.87 in the wild samples. These results indicated lower genetic variability in the hatchery population, as compared with the wild population and significant genetic differentiation between the wild population and the hatchery samples (F _ST=0.055, p<0.001). These microsatellite loci may be valuable for future population genetic studies and for tracking hatchery samples used in stock enhancement programs.     

长江水系草鱼遗传多样性的微卫星DNA分析

利用已发表的鲤微卫星引物在草鱼中进行PCR扩增,结果有5对引物(6个座位)能成功扩增并且有较高多态性,等位基因数在3-7个之间。这些异种扩增的草鱼微卫星符合孟德尔遗传规律。测序证明草鱼中的微卫星核心重复序列部分与鲤中的原始核心序列相似,也有一些变化。随后用这6个多态微卫星座位研究了来自长江水系的四个草鱼群体的遗传结构,结果显示每个群体的平均等位基因数在38与48之间,平均观测杂合度(Ho)在04000与05741之间,平均期望杂合度(HE)在04773与06489之间,有多个座位在不同的群体中偏离哈代-温伯格平衡。遗传距离分析表明四川群体与洞庭湖群体遗传距离最远,而嘉鱼群体与鄱阳湖群体遗传距离较近。分子变异分析(AMOVA)表明,群体内遗传变异与群体间遗传变异分别占总遗传变异的9560%与440%,固定系数(FST)为0044,这表明长江水系草鱼目前的群体分化很微弱。       

草鱼连续两代的雌核发育群体及湘江流域群体基因组DNA的微卫星比较分析

对湘江流域草鱼群体,一代及连续两代极体型人工诱导雌核发育草鱼群体基因组DNA的微卫星引物统计分析结果表明:湘江流域草鱼群体存在一定程度的遗传多态性;大多数被检测的微卫星位点上存在两个以上的等位基因,但遗传多样性程度较低。一代人工诱导雌核发育草鱼群体中个体的基因位点已基本纯合,但就整个群体而言,个体之间的基因型还不完全一致,表现出一定的多态性。连续两代人工诱导雌核发育草鱼群体中不仅所检测个体的基因位点已完全纯合,并且各个体的基因型也完全相同。这些观察结果说明所检测的两代人工诱导雌核发育草鱼群体是纯合的,经连续两代人工诱导雌核发育可能建立起草鱼纯系。该实验结果还发现不仅草鱼的微卫星位点上存在等位基因的多态性,而且微卫星位点本身也存在多态性;在人工诱导草鱼雌核发育的过程中不仅存在微卫星等位基因快速丢失的现象,而且也存在微卫星位点丢失的现象。因此,加强对自然水体中草鱼种质资源多样性的保护和利用各种现代生物学技术纯化、筛选和组合优良性状基因,是草鱼遗传育种中同样重要和不可或缺的两个方面。     

Genetic differentiation among common and selected hatchery populations of flounder: Evidence from RAPD markers

Randomly amplified polymorphism DNA (RAPD) analysis was performed in order to evaluate one common population and two selected hatchery populations of flounder Paralichthys olivaceus. A total of 90 individuals belonging to three populations were screened using 12 different RAPD primers. A total of 71 loci were produced in the three studied populations, and 43.5%, 42.4% and 42.2% of these loci were polymorphic over all the genotypes tested in common, susceptible and resistant populations, respectively. The number of loci detected by single primers ranged from four to eight. The average heterozygosites of common, susceptible and resistant populations were 0.112, 0.103 and 0.111, respectively. Compared with the common population, the two selected hatchery populations, susceptible and resistant, showed some genetic differences including a smaller number of loci, a smaller number of polymorphic loci, a smaller number of genotypes and a smaller Shannon index. The present study confirmed that it is important to detect the genetic variability of the selected hatchery population for the conservation of natural flounder resources.     

草鱼基因组DNA一些RAPD位点的遗传分析及分子标记筛选

RAPD技术的实验结果很容易因实验条件和反应参数的不同而造成差异。为了建立能通用的草鱼基因组多态性分析RAPD分子标记体系,需要利用RAPD位点按照孟德尔共显性规律遗传的特点,用不同遗传背景的材料对多态性的RAPD位点进行统计遗传学比较分析以判断其真实性。为此,本实验选择具有遗传多态性的湘江流域草鱼群体和经连续两代人工诱导雌核发育获得的雌核发育草鱼品系,对一些可能作为草鱼基因组DNA分子标记的RAPD位点进行了遗传学比较分析。所用的10条多态性随机引物共检测到30个多态性RAPD位点。两个不同遗传背景群体的遗传统计对比分析结果表明:这30个多态位性位点在湘江流域草鱼群体和雌核发育草鱼群体中的分布符合孟德尔遗传规律,可以作为草鱼基因组DNA分析的可靠分子标记。本实验的观察结果还表明:在人工诱导雌核发育过程中,存在RAPD位点的快速丢失现象,两次人工诱导雌核发育过程中共丢失了17个多态性位点。因此,加强对自然水体中草鱼种质资源多样性的保护和利用各种现代生物学技术纯化、筛选和组合优良性状基因,是草鱼遗传育种中同样重要和不可或缺的两个方面。       

Isolation and characterization of microsatellite markers in the South African abalone (Haliotis midae)

We report the isolation and characterization of 11 polymorphic microsatellite loci in the South African abalone Haliotis midae. These loci showed a range of five to 21 alleles per locus and observed heterozygosities ranging from 0.14 to 0.93 in a wild population of 32 individuals. All loci except four conformed to Hardy–Weinberg expectations and did not show linkage disequilibrium. The polymorphism exhibited at these loci indicate that they would be useful in determining levels of genetic variability in natural and commercial Haliotis midae populations as well as in parentage and Quantitative Trait Loci (QTL) analysis in hatchery reared abalone.     

Comparative genetic diversity of wild and hatchery-produced Pacific oyster (Crassostrea gigas) populations in Korea using multiplex PCR assays with nine polymorphic microsatellite markers

The Pacific oyster, Crassostrea gigas, is the most important and valuable commercial fishery species in Korea. Its farming started 20 years ago and is still rapid expansion in Korea. In this study, to maintain the genetic diversity of this valuable marine resource, possible genetic similarity and differences between the wild population and hatchery population in Tongyeong, Korea were accessed using multiplex assays with nine highly polymorphic microsatellite loci. A total of 250 different alleles were found over all loci. Despite a long history of hatchery practices, very high levels of polymorphism (mean alleles = 22.89 and mean heterozygosity = 0.92) were detected between the two populations. No statistically significant reductions were found in heterozygosity or allelic diversity in the hatchery population compared with the wild population. However, significant genetic heterogeneity was found between two populations. These results provide no evidence to show that hatchery practice of Pacific oyster in Korea has significantly affected the genetic variability of the hatchery stock. Although further studies are needed for comprehensive determinations of the hatchery and wild populations with increased number of Pacific oyster sample collections, information on the genetic variation and differentiation obtained in this study can be applied for genetic monitoring of aquaculture stocks, genetic improvement by selective breeding and designing of more efficient conservation management guidelines for these valuable genetic materials.     

鲤的微卫星引物对草鱼基因组分析适用性的初步研究

运用微卫星DNA-聚合酶链反应(STR—PCR)基因分型技术,选取已发表的28对鲤的微卫星引物,探讨鲤的引物用于草鱼基因组微卫星分析的可能性。通过优化PCR反应条件,消除了影子带和异源核酸双链分子两类微卫星相关假阳性带对STR—PCR分析的干扰。在此基础上,筛选出7对引物可在湘江野生草鱼基因组中扩增出特异性条带,占总数的25％;其中的4对引物(约占总数的14．3％)在8尾湘江野生草鱼小群体中即检测到了个体间等位基因的多态性。这些初步的结果表明鲤的微卫星引物可以用于草鱼基因组的分析。