水产动物重要经济性状相关联的微卫星标记研究进展

近年来,随着现代分子生物学及统计学分析方法的快速发展,水产动物重要经济性状相关性研究已成为当前分子育种研究的热点。本文重点介绍了近年来微卫星分子标记在水产动物几个主要经济性状相关性研究中的进展,讨论当前研究中存在的问题,并展望了水产动物经济性状相关微卫星标记的研究前景。     

鳜(♀)×斑鳜(♂)杂种F_1的形态特征与微卫星分析

2006-2008年,在浙江湖州开展了鳜(Siniperca chautsi)与斑鳜(Siniperca scherzeri)的种间杂交试验,并成功获得了鳜(♀)×斑鳜(♂)杂种F1。通过对杂种F1与其亲本的形态差异比较和微卫星标记分析,探讨了杂种F1的性状变异和遗传特征。结果表明:(1)7个可数性状中,杂种F1的背鳍条、腹鳍条和胸鳍条数与父母本一致,臀鳍条、鳃耙数与母本基本一致,侧线鳞、幽门盲囊数目介于父、母本之间;10个可量性状的平均杂种指数为39.08,显示杂种F1的可量性状略偏向母本;框架参数和可量性状的聚类分析、判别分析和主成份分析表明,杂种F1的体型介于父、母本之间,略倾向于母本,主要表现在躯干部和尾部的差异。(2)5对微卫星引物分析表明,杂种F1的等位基因均来源于双亲,杂交子代的遗传符合孟德尔遗传规律,属两性融合生殖,是真正意义上的杂交种。     

家鸡微卫星引物在灰胸竹鸡中的跨种扩增和特征分析

灰胸竹鸡(Bambusicola thoracica)是中国特有鸟类.利用近缘种家鸡(Gallus gallus)中已发表的微卫星DNA标记引物,对灰胸竹鸡进行跨种扩增,得到10个多态位点.每个位点的等位基因数为4-13个,观察杂合度为0.1220-1.000,期望杂合度为0.1183-0.8898.4对引物显著偏离Hardy-Weinberg平衡.这些引物将为研究灰胸竹鸡的系统地理学和保护遗传学提供非常有用的工具.     

鳜(♀)×斑鳜(♂)杂种F_1的形态特征与微卫星分析

2006-2008年,在浙江湖州开展了鳜(Siniperca chautsi)与斑鳜(Siniperca scherzeri)的种间杂交试验,并成功获得了鳜(♀)×斑鳜(♂)杂种F1。通过对杂种F1与其亲本的形态差异比较和微卫星标记分析,探讨了杂种F1的性状变异和遗传特征。结果表明:(1)7个可数性状中,杂种F1的背鳍条、腹鳍条和胸鳍条数与父母本一致,臀鳍条、鳃耙数与母本基本一致,侧线鳞、幽门盲囊数目介于父、母本之间;10个可量性状的平均杂种指数为39.08,显示杂种F1的可量性状略偏向母本;框架参数和可量性状的聚类分析、判别分析和主成份分析表明,杂种F1的体型介于父、母本之间,略倾向于母本,主要表现在躯干部和尾部的差异。(2)5对微卫星引物分析表明,杂种F1的等位基因均来源于双亲,杂交子代的遗传符合孟德尔遗传规律,属两性融合生殖,是真正意义上的杂交种。     

Genetic diversity of Forest and Savannah chicken populations of Ghana as estimated by microsatellite markers

The characterization of indigenous animal genetic resources is a requisite step in providing needed information for the conservation of useful genotypes against future needs. Thus, in this study, 22 microsatellite markers were used to genotype 114 local chickens from the Forest (n = 59) and Savannah (n = 55) eco‐zones of Ghana and the results compared to those of the ancestral red junglefowl (n = 15) and two European commercial chicken populations – a broiler (n = 25) and white leghorn (n = 25). A total of 171 alleles were observed, with an average of 7.8 alleles per locus. The local Ghanaian chickens showed higher diversity in terms of the observed number of alleles per locus (6.6) and observed heterozygosity (0.568) compared with the combined control populations (6.0 and 0.458, respectively). However, Wright's F‐statistics revealed negligible genetic differentiation (F_ST) in local Ghanaian chicken populations. In addition, 65% of the Savannah chickens were inferred to be more likely from the Forest, suggesting a south‐north dispersal of chickens from their probable original location in the Forest zone to the Savannah areas. It is concluded that the Forest and Savannah chickens of Ghana are a single, randomly mating unselected population, characterized by high genetic diversity and constitute a valuable resource for conservation and improvement.     

贵州省东方蜜蜂微卫星DNA遗传分化与遗传多样性分析

利用31个微卫星位点对贵州全省的东方蜜蜂进行分析.结果表明:贵州省东方蜜蜂遗传分化系数(FST)为0~0.03,没有发现贵州省东方蜜蜂发生遗传分化.贵州省东方蜜蜂微卫星平均期望杂合度为0.434 5±0.055 0,平均观察杂合度为0.419 6±0.011 4,平均等位基因数为5.56±4.34,平均有效等位基因数为2.693 0±2.113 5,平均香农指数为0.873 5±0.797 1.贵州省东方蜜蜂微卫星遗传多样性高于全国东方蜜蜂的平均水平.本文研究结果对了解我国东方蜜蜂遗传结构、遗传分化和遗传多样性水平具有重要的价值,对指导贵州省东方蜜蜂遗传资源保护与利用提供理论依据.     

基于RNA-seq数据大规模挖掘蜜蜂球囊菌的SSR分子标记

基于已获得的球囊菌转录组数据预测微卫星标记(SSR),并进行SSR位点的信息分析和SSR引物的挖掘.利用软件MISA对球囊菌转录组中42610条unigenes进行搜索,共预测出7968个SSRs,分布于5233条unigenes中,其中最主要的重复类型为三核苷酸重复(53.15%),其次为二核苷酸重复(32.32%)和四核苷酸重复(8.46%).二核苷酸重复中的基序主要是AG/CT(占总量的15.8%).针对所有的SSR位点,利用Primer Premier 5软件设计出6956对SSR特异性引物,随机选取20对引物对两个不同来源的球囊菌样品进行SSR位点扩增,共有6对引物成功扩增出符合预期的目的片段.研究结果表明,利用球囊菌转录组数据开发SSR引物是可行的.     

蓝塘×长白猪F2资源群1、4和8号 染色体活体性状的QTL定位

 【目的】鉴定影响猪重要经济性状的QTL。【方法】利用中国地方猪种蓝塘猪（16头母猪）与外来品种长白猪（8头公猪）建立了资源家系,对257头F2代个体的11个活体性状进行测定。根据美国肉畜中心（USDA-MARC 2.0）公布的猪连锁图谱,在1、4和8号染色体上大约每间隔10—20 cM选择一个微卫星标记,共21个标记,采用ABI 377 DNA序列分析仪进行微卫星基因分型,运用QTL Express 软件包在http://latte.cap.ed.ac.uk网站在线分析,进行QTL定位分析。【结果】体高（body height,BodyHh）的QTL定位于SSC1的68 cM处,与标记SW2185（67.6cM）紧密联锁,达到染色体显著水平（P＜0.05）,解释表型变异的2.22%。体长（body length,BodyLh）的QTL定位于SSC4上的72cM处,位于标记SW839—SW0214,达到染色体显著水平（P＜0.05）。【结论】在猪1和4号染色体上分别检测到一个影响体高和体长的QTL,为今后的QTL精细定位、大片段功能基因的克隆分析、以及猪分子育种技术的应用提供参考依据。     

5个重庆地方猪种遗传多样性的微卫星分析

为了分析5个重庆地方猪种的遗传多样性和系统发生关系,采用FAO-ISAG联合推荐的27个微卫星标记,以有效等位基因数、期望杂合度和多态信息含量等遗传参数为指标,评估了品种内遗传变异。计算了F统计量、Nei氏遗传距离(DA)和Nei氏标准遗传距离(DS)并进行UPGMA和NJ聚类分析及主成分分析,进而探讨了品种间的遗传分化和亲缘关系。结果,27个微卫星座位共检测到542个等位基因,其中43个等位基因为单一品种所特有。5个猪种的遗传多样性丰富:有效等位基因数(Ne)在9.4933～11.0280之间,期望杂合度(He)在0.8897～0.9091之间,多态信息含量(PIC)在0.8689～0.8926之间。F统计量分析表明,重庆地方猪种遗传分化明显(P0.001),各群体内存在一定程度的近交。2种聚类方法以NJ法更为可靠。5个猪种聚为两类,荣昌猪、渠溪猪和合川猪为一类,罗盘山猪和盆周山地猪为一类。相关性分析表明,遗传距离与地理距离间无显著的相关(P0.05)。该研究结果为重庆地方猪种的保护和利用提供了重要的理论依据。     

Genetic and morphometric characterization of a local Vietnamese Swamp Buffalo population

The water buffalo plays a key role in the socio-economy of South-East Asia as it is the main draught power for paddy rice cultivation. While in the Indian subcontinent the water buffalo is the riverine type, in South-East Asia the majority of buffaloes are of the swamp type. In the poor remote northern province of Ha Giang in Vietnam, improvement of the swamp buffalo breed may be one of the best ways to increase sustainability of farming systems. Therefore, analysis of the genetic structure of the province buffalo population is a prerequisite to any conservation or improvement project. A total of 1122 animals were described for 11 body and horn measurements for morphometric characterization. From this sample set, 744 animals were genotyped for 17 microsatellite markers. Also 17 animals from southern provinces of Vietnam were genotyped as a comparative sample. The results showed that genetic diversity as well as inbreeding value in the Ha Giang was high. The F _ST values within the province and across Vietnam were low indicating that most of the population variation is explained by individual variability. Bayesian clustering analysis did not highlight the presence of subdivided populations. These results are useful for the implementation of a conservation and improvement strategy of the swamp buffalo in order to guarantee the householders' needs for sustainability of the farming system in the Ha Giang province.