Shang Hai Tao, Wei Hong, Yue Bing Fei, Xu Ping
Department of Laboratory Animal Science, College of Basic Medicine, Third Military Medical University, Chongqing 400038, China.
Fen Zi Xi Bao Sheng Wu Xue Bao. 2008 Feb;41(1):28-34.
Genetic quality of outbred stock has an important effect for the experimental results by using those animals, but methods and standardization of genetic detection for outbred stock are absent. In the present study, 6 microsatellite markers were screened for Wistar from Beijing and Spague-Darley (SD) from Shanghai outbred rats by fluorescence-based semi-automated genotyping method. Good polymorphisms were detected on all the 6 microsatellite loci, with 36 alleles found in the 2 stocks, 5-8 alleles each locus, and the polymorphic information content (PIC) ranged from 0.5892 (D11Mgh3) to 0.8019 (D6Mit1), with an average of 0.6881. 25 and 26 alleles were detected in the 6 loci, and averages of unbiased expected heterozygosity were 0.6260 and 0.6249 in Wistar and SD outbred rats, respectively. No significant differences of genetic diversity index were tested between populations. The Fst per locus was varied from 0.0461 to 0.4363, and the average Fst of all loci was 0.2069, which implied large genetic differentiation between populations. Nei's (1972) genetic distance and Nei's (1978) unbiased genetic distance measures between the 2 stocks were 1.2862 and 1.2726, respectively, which indicated the distant genetic relationship and low genetic identity between them. All loci in Wistar and 4 of 6 loci in SD outbred rats showed significant deviations from Hardy-Weinberg equilibrium (HWE), and all deviations were caused by deficiency of heterozygous individuals. From the results, there is abundant genetic variation in Wistar and SD outbred rats. Large genetic differentiation existed between these two outbred stocks, and each possessed distinct genetic characteristic. Deviation from HWE seems a frequent problem in the 2 outbred stocks. This genetic research on outbred rats should assist in developing genetic monitoring methods and standardization of the outbred rats.
远交群动物的遗传质量对使用这些动物所获得的实验结果有重要影响，但目前缺乏远交群动物遗传检测的方法和标准化。在本研究中，采用基于荧光的半自动基因分型方法，从北京的Wistar大鼠和上海的Sprague-Dawley（SD）大鼠中筛选了6个微卫星标记。在所有6个微卫星位点均检测到良好的多态性，在这两个种群中共发现36个等位基因，每个位点有5 - 8个等位基因，多态信息含量（PIC）范围为0.5892（D11Mgh3）至0.8019（D6Mit1），平均为0.6881。在6个位点分别检测到25个和26个等位基因，Wistar大鼠和SD大鼠的无偏期望杂合度平均值分别为0.6260和0.6249。在种群间未检测到遗传多样性指数的显著差异。每个位点的Fst值在0.0461至0.4363之间，所有位点的平均Fst为0.2069，这意味着种群间存在较大的遗传分化。两个种群之间的Nei（1972）遗传距离和Nei（1978）无偏遗传距离分别为1.2862和1.2726，这表明它们之间的遗传关系较远且遗传同一性较低。Wistar大鼠的所有位点以及SD大鼠6个位点中的4个位点均显著偏离哈迪-温伯格平衡（HWE），所有偏差均由杂合个体的缺乏引起。结果表明，Wistar大鼠和SD大鼠具有丰富的遗传变异。这两个远交群之间存在较大的遗传分化，且各自具有独特的遗传特征。偏离HWE似乎是这两个远交群中常见的问题。对远交大鼠的这种遗传研究应有助于开发远交大鼠的遗传监测方法和标准化。
