Korchagin V I, Martirosian I A, Omel'chenko A V, Darevskiĭ I S, Ryskov A P, Tokarskaia O N
Genetika. 2004 Oct;40(10):1336-42.
The genesis of mini- and microsatellite loci, which is under extensive study in humans and some other bisexual species, have been virtually overlooked in species with clonal mode of reproduction. Earlier, using multilocus DNA fingerprinting, we have examined variability of some mini- and microsatellite DNA markers in parthenogenetic lizards from the genus Darevskia. In particular, mutant (GATA)n-restrictive DNA fragments were found in Darevskia unisexualis. In the present study, we examined intraspecific polymorphism of three cloned loci of D. unisexualis--Du323, Du215, and Du281--containing (GATA)7GAT(GATA)2, GAT(GATA)9, and (GATA)10TA(GATA) microsatellite clusters, respectively. Different levels of intrapopulation and interpopulation variability of these loci were found. Locus Du281 showed the highest polymorphism--six allelic variants (in the sample of 68 DNA specimens). Three alleles were found for locus Du215. The Du325 locus was electrophoretically invariant. The primers chosen for loci Du323, Du215, and Du281 were also used for PCR analysis of homologous loci in two presumptive parental bisexual species, D. valentini and D. nairensis. The PCR products of the corresponding loci of the parental species had approximately the same size (approximately 200 bp) as their counterparts in D. unisexualis, but the polymorphism levels of the paternal, maternal, and hybrid species were shown to be somewhat different. These data on the structure of the D. unisexualis loci provide a possibility to study genetic diversity in the parthenogenetic species D. unisexualis and other related unisexual and bisexual species of this genus, which can provide new information on the origin of parthenogenetic species and on the phylogenetic relationships in the genus Darevskia. These data can also be used for resolving problems of marking the lizard genome, which is still poorly studied.
微卫星和小卫星基因座的起源在人类和其他一些两性物种中受到广泛研究,但在无性繁殖模式的物种中几乎被忽视。早些时候,我们利用多位点DNA指纹技术,研究了Darevskia属孤雌生殖蜥蜴中一些微卫星和小卫星DNA标记的变异性。特别是,在单性蜥蜴Darevskia unisexualis中发现了突变的(GATA)n限制性DNA片段。在本研究中,我们检测了D. unisexualis三个克隆基因座——Du323、Du215和Du281——的种内多态性,它们分别包含(GATA)7GAT(GATA)2、GAT(GATA)9和(GATA)10TA(GATA)微卫星簇。发现这些基因座在种群内和种群间存在不同程度的变异性。基因座Du281表现出最高的多态性——在68个DNA样本中有六个等位基因变体。基因座Du215发现了三个等位基因。Du325基因座在电泳上是不变的。为基因座Du323、Du215和Du281选择的引物也用于对两个假定的亲本两性物种D. valentini和D. nairensis的同源基因座进行PCR分析。亲本物种相应基因座的PCR产物大小与D. unisexualis中的对应产物大致相同(约200 bp),但父本、母本和杂种物种的多态性水平有所不同。这些关于D. unisexualis基因座结构的数据为研究孤雌生殖物种D. unisexualis以及该属其他相关的无性和两性物种的遗传多样性提供了可能性,这可以为孤雌生殖物种的起源以及Darevskia属的系统发育关系提供新信息。这些数据也可用于解决蜥蜴基因组标记问题,蜥蜴基因组目前仍研究不足。