山东省地方绵羊品种间表型与遗传关系分析

利用24个微卫星标记、7个生长发育性状和7个血液常规指标,构建了小尾寒羊、寒羊、山地绵羊、洼地绵羊4个山东地方绵羊品种及1个杂交羊(杜泊绵羊×小尾寒羊)群体的系统发生树,研究了群体间的生物相似性和遗传进化关系。结果表明,3种聚类方法的涵义不同,其结果有较大差异。从生物学性状上,在较近的地理距离内,不同绵羊品种生长性状和生理状态的差异显著(P<0.01或P<0.05),证明生态环境、饲养条件和选择方式对品种的形成具有重要影响。从遗传关系上,4个绵羊品种的GST和DST值分别为0.028和0.025,群体组合的FST值较低(0.025 5~0.039 0),FIS值较高(0.360 1~0.446 7),说明品种间遗传分化程度不高,亲缘关系较近,群体内近交程度较高,其基因流趋向与地理分布距离、遗传距离相一致,故防止无控制的近交和杂交是保持每个品种纯度的主要措施。     

5个白鹅群体的遗传结构和进化分析

应用微卫星标记对我国5个白鹅品种资源群体(太湖鹅、四川白鹅、织金白鹅、伊犁鹅、皖西白鹅)的遗传结构和进化进行了研究。结果表明:(1)5个白鹅群体的平均杂合度都较高,反映了各鹅种群体内的遗传变异较大,各鹅种的适应性较强;(2)通过计算DS遗传距离和UPG-MA聚类,发现5个白鹅群体间的遗传距离较远,分化时间较长,5个白鹅群体分别独自为一类,聚类结果反映了5个鹅品种的进化与它们的选育历史及地理分布关系密切。应加强对我国现有鹅种资源的保护力度和开发力度。     

微卫星标记BM1329在2个山羊品种中的初步研究

依据微卫星标记在相近物种中具有高度保守性这一特点,选择与绵羊高繁殖力主效基因FecB紧密连锁的一个微卫星标记BM1329,分析其在云南黑山羊和努比山羊中的多态性以及与山羊产羔数的关系。结果表明:微卫星标记BM1329在2个山羊品种中均存在AA、AB和BB型3种基因型。统计检验表明,品种与基因型显著相关,云南黑山羊以AA型为主,努比羊以AB型为主。虽然本研究表明微卫星标记BM1329不同基因型最小二乘山羊产羔均数差异不显著,但云南黑山羊与努比羊的产羔数差异极显著,即存在AB型山羊产羔数大于AA型山羊产羔数的趋势,所以微卫星标记BM1329仍可作为探讨山羊高繁殖性能的一个候选标记进行深入研究。     

固始鸡不同品系及部分外来鸡种遗传多样性的微卫星分析

利用10个微卫星标记,对固始鸡5个系和4个非固始鸡品系共9个群体的等位基因频率、遗传杂合度、群体间的遗传距离等进行了分析,并根据遗传距离进行了聚类分析。结果表明:星红褐鸡与绿壳蛋鸡被聚为一类,固始鸡慢羽系与快羽系被聚为一类,固始鸡被聚为一大类,罗曼鸡自成一类,艾维茵鸡也自成一类。     

黄淮山羊微卫星多态性及其与产羔数相关性的研究

以绵羊FecB、GDF9和BMP15为候选基因,同时选择绵羊6号染色体与FecB基因紧密连锁的6个微卫星标记,分析其在黄淮山羊中的多态性及其与产羔数的关系。结果表明:在黄淮山羊中均未发现FecB、GDF9基因和BMP15基因突变。微卫星Lscv043、BMS2508、300U、GC101均为多态位点;而GC101与产羔数具有较强的相关性,在GC1013种基因型中200bp/238bp基因型群体对应的第1胎产羔数和第2胎产羔数均显著高于其他2种基因型群体的对应产羔数(P<0.05);但是各基因型群体之间第3胎产羔数差异不明显;同样基因型200bp/238bp对应群体的平均产羔数极显著高于其他2种基因型群体的平均产羔数(P<0.01)。其他位点的不同基因型群体之间产羔数差异均不明显。这些结果表明,FecB基因所在区域位点对山羊产羔数亦具有一定影响,可以作为山羊早期选育的理论依据。     

四川地方乌骨鸡种群遗传变异的微卫星DNA分析

利用10个微卫星标记，对四川不同地区5个乌骨鸡种群的等位基因频率、各群体的遗传杂合度、群体间的遗传距离等进行了分析，并根据遗传距离对这几个乌骨鸡种群进行了聚类分析。结果表明，各乌骨鸡群体的遗传多样性较为丰富，并具有较高的选择潜力。各乌骨鸡种群间有一定的遗传距离，UPGMA聚类分析表明，四川山地乌骨鸡黑羽系与川南山地乌骨鸡被聚为一类，草科鸡与旧院黑鸡被聚为一类。     

Kinship analysis reveals reproductive success skewed toward overwintered Brandt's voles in semi‐natural enclosures

Age structure and seasonality influence the population fluctuations of small rodents. Age determines body weight and social experience, while seasonality regulates the duration of the breeding season and onset of sexual maturity in newborn offspring. Therefore, reproductive success and skew usually occur in different age groups. Brandt's vole (Lasiopodomys brandtii) is a social, short‐lived and seasonal breeding small rodent with a dramatic seasonal population fluctuation, but reproductive skew is not fully understood in this species. In the present study, we determined kinship in semi‐natural enclosure populations using microsatellite markers based on genotyping, analyzed the reproductive skew between sexes and between overwintered and newborn voles, and monitored variation in male reproductive activity by testing fecal testosterone levels throughout the year. Overwintered voles had the most reproductive success along with a striking increase in the population size in the enclosures, with all biological fathers and 77.8% of biological mothers, which had 100% and 87% of the total offspring, respectively. Compared to overwintered voles, reproductive skews were significantly higher in potential overwintered and newborn parents, implying the possible reproductive suppression of newborn voles by dominant overwintered voles. Moreover, both heavier body weight and higher testosterone levels in overwintered males supported their potential social status in the population. Our study provided new evidence for reproductive skew and differentiation of postnatal gonadal development patterns of different age groups in Brandt's vole.     

Evaluation of recent changes in genetic variability in Japanese thoroughbred population based on a short tandem repeat parentage panel

The integrity of thoroughbreds is maintained under strict regulation involving DNA parentage testing, which is robust in a population with high genetic variability. The genetic variability of the thoroughbred population is possibly fluctuating because of selective breeding that has focused on adaptations for racing performance. To monitor genetic variability within the population and the effectiveness of short tandem repeat (STR) parentage testing, we investigated allele frequencies and the exclusion probability (PE) of 16–17 loci of a parentage panel in the Japanese thoroughbred population over 15 years. Expected heterozygosities (He) of 14 loci indicated a decreasing trend, and the average He of the population decreased significantly. Low genetic variability was possibly induced by a decrease in population size and a selective breeding bias. Four loci showed both a significant increase in allele frequency and a significant decrease in He; it is assumed that those loci were affected by positive selection for racing performance. There was a significant decrease in the PE because of the changes in genetic variability; however, it has remained over 0.99995. The current STR panel is still effective for parentage control, but it will be necessary to continuously monitor genetic variability, which has decreased over 15 years.     

岷县黑裘皮羊微卫星遗传多样性分析

试验旨在分析岷县黑裘皮羊群体内遗传多样性,筛选出理想的遗传标记,为岷县黑裘皮羊的选育保种提供理论依据。选取144只岷县黑裘皮羊,颈静脉采血并提取DNA,对24对微卫星引物进行PCR扩增,用毛细管电泳技术进行基因分型,计算其等位基因数、等位基因大小及频率、有效等位基因数、杂合度和多态信息含量。结果显示,24个位点共检测到210个等位基因,平均等位基因数为8.75;群体等位基因频率为0.0104~0.7396,等位基因片段大小为97~285 bp;有效等位基因数为1.7581~8.2433个;群体平均观测杂合度为0.4839;平均期望杂合度为0.6959;平均多态信息含量为0.6527。其中MAF70位点等位基因数、有效等位基因数、期望杂合度和多态信息含量最高;OarFCB128位点观测杂合度最高;OarAE129位点等位基因数最少,SRCRSP9位点期望杂合度、多态信息含量最低;OarFCB304位点观测杂合度最低。Hardy-Weinberg平衡分析结果表明,所选位点中有19个处于非平衡状态。结果表明,岷县黑裘皮羊的遗传背景复杂,群体内遗传多样性丰富,可为其遗传资源的评估和选育保种工作提供理论依据。     

10个云南地方猪种微卫星遗传多样性分析

为阐明保山猪、迪庆藏猪、高贡黎山猪、丽江猪、明光小耳猪、滇南小耳猪、撒坝猪、大河猪、昭通猪、大河乌猪10个云南省优良地方猪种的群体遗传多样性和遗传结构,本试验参考ArkDB数据库中家猪14条染色体上的15对微卫星引物,对549个云南地方猪个体的耳组织样品进行了检测分析,计算各微卫星座位等位基因数（Na）、有效等位基因数（Ne）、Shannon's信息指数（I）、表观杂合度（Ho）、期望杂合度（He）、F-统计量（Fis、Fit、Fst）、基因流（Nm）、群体遗传距离等相关参数及多态信息含量（PIC）,采用NTsys 2.10软件构建聚类树,并采用STRUCTRUE 2.3.3软件评估群体遗传结构。结果显示：15个微卫星座位共检测到293个等位基因,各座位等位基因数在5~38个之间,平均等位基因数为19个,平均有效等位基因数8.3682个;10个云南地方猪群体的Shannon多样性、表观杂合度、期望杂合度和多态信息含量分别在1.4374~2.0317、0.6389~0.7756、0.7021~0.8281和0.6647~0.7993之间。各座位单个群体内近交系数（Fis）、总群体近交系数（Fit）、群体间遗传分化系数（Fst）的变化范围分别为-0.0678~0.4594、0.0618~0.5567和0.0713~0.1801;群体间Fst平均值为0.1101,处于中度遗传分化状态,有11.01%的遗传变异来自于群体间,大部分遗传变异来自于群体内;每个座位基因流程度较高,变化范围在1.6392~3.2551之间,平均值为2.0214。基于Nei氏遗传距离构建UPGMA系统发生树显示,高黎贡山猪与迪庆藏猪聚为一支,并与丽江猪、保山猪和明光小耳猪聚为一大支,其结果得到了STRUCTURE分析的验证。综上所述,10个云南地方猪种遗传多样性丰富,群体内有近交现象,群体间处于中度遗传分化,存在着一定的基因交流。