Tokarskaya O N, Kan N G, Petrosyan V G, Martirosyan I A, Grechko V V, Danielyan F D, Darevsky I S, Ryskov A P
Institute of Gene Biology, Russian Academy of Sciences, Moscow.
Mol Genet Genomics. 2001 Jul;265(5):812-9. doi: 10.1007/s004380100475.
Multilocus DNA fingerprinting has been used to study the variability of some mini- and microsatellite sequences in parthenogenetic species of Caucasian rock lizards of the genus Lacerta (L. dahli, L. armeniaca and L. unisexualis). We demonstrate that these clonally reproducing lizards possess species-specific DNA fingerprints with a low degree of intra- and interpopulation variation. Mean indices of similarity obtained using M13 DNA, (GACA)4 and (TCC)50 as probes were 0.962 and 0.966 in L. dahli and L. armeniaca, respectively. The mean index of similarity obtained using M 13 and GATA probes in L. unisexualis was estimated to be 0.95. However, despite the high degree of band-sharing, variable DNA fragments were revealed in all populations with the microsatellite probes. An particularly high level of variability was observed for (TCC)n microsatellites in populations of L. unisexualis. In fact TCC-derived DNA fingerprints were close to being individual-specific, with a mean index of similarity of 0.824. Fingerprint analysis of parthenogenetic families of L. armeniaca showed that all maternal fragments were inherited together by the progeny, and no differences in fingerprint patterns were observed. On the other hand, while identical DNA fingerprints were obtained from L. unisexualis families with M13 and (GATA)4 probes, use of the (TCC)50 probe revealed remarkable intrafamily variation in this species. It is assumed that the genetic heterogeneity observed in parthenogenetic populations may be explained, at least in part, by the existence of genetically unstable microsatellite loci. Our data serve to illustrate processes of spontaneous mutagenesis and the initial stages of clonal differentiation in natural populations of the lizard species studied.
多位点DNA指纹图谱已被用于研究蜥蜴属（Lacerta）高加索岩蜥孤雌生殖物种（达氏蜥蜴、亚美尼亚蜥蜴和单性蜥蜴）中一些小卫星和微卫星序列的变异性。我们证明，这些进行克隆繁殖的蜥蜴拥有物种特异性的DNA指纹图谱，种群内和种群间的变异程度较低。以M13 DNA、(GACA)4和(TCC)50作为探针，在达氏蜥蜴和亚美尼亚蜥蜴中获得的平均相似性指数分别为0.962和0.966。在单性蜥蜴中，使用M13和GATA探针获得的平均相似性指数估计为0.95。然而，尽管存在高度的条带共享，但使用微卫星探针在所有种群中都发现了可变的DNA片段。在单性蜥蜴种群中，观察到(TCC)n微卫星具有特别高的变异性。事实上，源自TCC的DNA指纹图谱几乎接近个体特异性，平均相似性指数为0.824。对亚美尼亚蜥蜴孤雌生殖家族的指纹分析表明，所有母体片段都由后代共同遗传，并且未观察到指纹图谱的差异。另一方面，虽然使用M13和(GATA)4探针从单性蜥蜴家族中获得了相同的DNA指纹图谱，但使用(TCC)50探针揭示了该物种家族内显著的变异。据推测，在孤雌生殖种群中观察到的遗传异质性至少部分可以通过遗传不稳定的微卫星位点的存在来解释。我们的数据有助于说明所研究蜥蜴物种自然种群中的自发诱变过程和克隆分化的初始阶段。
