两种澳大利亚石龙子（有鳞目：鬣蜥科：两栖石龙子亚科）的核型特征揭示了具有相似核型的相关物种之间微妙的染色体重排。

Karyotype Characterisation of Two Australian Dragon Lizards (Squamata: Agamidae: Amphibolurinae) Reveals Subtle Chromosomal Rearrangements Between Related Species with Similar Karyotypes.

机构信息

Centre for Conservation Ecology and Genetics, Institute for Applied Ecology, University of Canberra, Bruce, Australian Capital Territory, Australia,

Centre for Conservation Ecology and Genetics, Institute for Applied Ecology, University of Canberra, Bruce, Australian Capital Territory, Australia.

出版信息

Cytogenet Genome Res. 2020;160(10):610-624. doi: 10.1159/000511344. Epub 2020 Nov 18.

DOI:10.1159/000511344

PMID:33207346

Abstract

Agamid lizards (Squamata: Agamidae) are karyotypically heterogeneous. Among the 101 species currently described from Australia, all are from the subfamily Amphibolurinae. This group is, with some exceptions, karyotypically conserved, and all species involving heterogametic sex show female heterogamety. Here, we describe the chromosomes of 2 additional Australian agamid lizards, Tympanocryptis lineata and Rankinia diemensis. These species are phylogenetically and cytogenetically sisters to the well-characterised Pogona vitticeps, but their sex chromosomes and other chromosomal characteristics are unknown. In this study, we applied advanced molecular cytogenetic techniques, such as fluorescence in situ hybridisation (FISH) and cross-species gene mapping, to characterise chromosomes and to identify sex chromosomes in these species. Our data suggest that both species have a conserved karyotype with P. vitticeps but with subtle rearrangements in the chromosomal landscapes. We could identify that T. lineata possesses a female heterogametic system (ZZ/ZW) with a pair of sex microchromosomes, while R. diemensis may have heterogametic sex chromosomes, but this requires further investigations. Our study shows the pattern of chromosomal rearrangements between closely related species, explaining the speciation within Australian agamid lizards of similar karyotypes.

摘要

鬣蜥科蜥蜴（有鳞目：鬣蜥科）的染色体具有多样性。在澳大利亚目前描述的 101 种蜥蜴中，所有物种均属于 Amphibolurinae 亚科。这个亚科的染色体在很大程度上是保守的，所有涉及异型性别的物种都表现为雌性异型性。在这里，我们描述了另外两种澳大利亚鬣蜥（Tympanocryptis lineata 和 Rankinia diemensis）的染色体。这两个物种在系统发育和细胞遗传学上与特征明显的 Pogona vitticeps 密切相关，但它们的性染色体和其他染色体特征尚不清楚。在这项研究中，我们应用了先进的分子细胞遗传学技术，如荧光原位杂交（FISH）和跨物种基因定位，以对这些物种的染色体进行特征描述并识别性染色体。我们的数据表明，这两个物种的染色体都与 P. vitticeps 具有保守的核型，但在染色体景观上有细微的重排。我们可以确定 T. lineata 具有雌性异型性系统（ZZ/ZW），并拥有一对性染色体微染色体，而 R. diemensis 可能具有异型性染色体，但这需要进一步的研究。我们的研究显示了在密切相关的物种之间染色体重排的模式，解释了具有相似核型的澳大利亚鬣蜥属内的物种形成。