PDF(Pubmed)
Abstract：
This paper describes the preparation of flow-sorted chromosome paints from the Iberian Rock lizard Iberolacerta monticola, exemplifying their subsequent use in cross-species comparisons of chromosome painting. We carried out comparative analyses of chromosome evolution in the congeneric species I. galani and I. bonnali, as well as in two other species of Lacertini (Lacerta schreiberi and Timon lepidus) whose sex chromosomes were also studied through comparative genomic hybridization. Most species of Lacertini possess a diplod number of 2n = 38, with 36 acrocentric macrochromosomes and 2 microchromosomes. However, the nine species included in the genus Iberolacerta do not possess microchromosomes. Furthermore, very conspicuous differences from the standard Lacertini karyotype were observed in the three Pyrenean species of this genus, which included several biarmed metacentrics and a Z1Z2W multiple sex-chromosome system. With the possible exception of L. schreiberi, all the species of the family Lacertidae described to date appear to share homologous Z chromosomes, which date back to the last common ancestor of the whole group. We provide conclusive evidence that L. schreiberi should no longer be considered an exception to this rule, and demonstrate that the loss of microchromosomes in Iberolacerta was produced by their fusion to a middle-sized chromosome. Furthermore, we show that the multiple sex-chromosome system of the Pyrenean species of Iberolacerta originated from the fusion of the ancestral W chromosome with one of the shortest autosomes, and provide additional evidence of the fast evolution of DNA sequences linked to the W chromosome in Lacertini.
摘要：
本文介绍了伊比利亚岩蜥蜴Iberolacertamonticola的流动分选染色体涂料的制备方法，举例说明了它们随后在染色体绘画的跨物种比较中的用途。我们对同属物种I.galani和I.bonnali的染色体进化进行了比较分析，以及其他两个Lacertini物种（Lacertaschreiberi和Timonlepidus），它们的性染色体也通过比较基因组杂交进行了研究。大多数Lacertini物种的双杆数为2n=38，具有36个顶心大染色体和2个微染色体。然而,Iberolacerta属中的9个物种不具有微染色体。此外，在该属的三个比利牛斯属物种中观察到与标准Lacertini核型非常明显的差异，其中包括几个双臂亚中心和一个Z1Z2W多性染色体系统。可能除了L.schreiberi,迄今为止描述的Lacertidae家族的所有物种似乎都共享同源Z染色体，可以追溯到整个群体的最后一个共同祖先。我们提供了确凿的证据，证明L.schreiberi不应再被视为该规则的例外，并证明Iberolacerta微染色体的丢失是由它们融合到中等大小的染色体引起的。此外，我们表明，伊比罗拉克塔比利牛斯属物种的多性染色体系统起源于祖先W染色体与最短的常染色体之一的融合，并提供了与Lacertini中W染色体相关的DNA序列快速进化的其他证据。
