Complex evolution of X and Y autosomal translocations in the giant mole-rat, Cryptomys mechowi (Bathyergidae)
Complex evolution of X and Y autosomal translocations in the giant mole-rat, Cryptomys mechowi (Bathyergidae)
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DOI：
10.1007/s10577-006-1080-3
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发表时间：
2006-09-01
影响因子：
2.6
通讯作者：
Robinson, T. J.
中科院分区：
文献类型：
--
作者：
Deuve, J. L.;Bennett, N. C.;Robinson, T. J.
跨种染色体涂绘方法用于确定裸鼹鼠Heterocephalus glaber （2n = 60）和巨鼹鼠Cryptomys mechowi （2n = 40）两种鼹鼠的同源染色体区域，使用流分选涂绘探针代表了除两种H. glaber染色体补体外的所有物种。在mechowi基因组中共鉴定出43个同源区域。8条H. glaber染色体在C. mechowi中完整保留，13条在该物种中产生两个或多个信号。这两个类群的核型最显著的差异在于它们的性染色体。H. glaber绘画探针发现了一系列复杂的易位，包括四个常染色体的分离和随后的片段易位到性染色体和常染色体的伴侣。在与易位常染色体段交界处，检测到一种腔间异色阻滞（IHB）。我们讨论了导致C. mechowi性染色体当代组成的可能的进化事件序列，并根据关于哺乳动物性染色体起源的流行观点来考虑这些事件。
Cross-species chromosome painting was used to determine homologous chromosomal regions between two species of mole-rat, the naked mole-rat, Heterocephalus glaber (2n = 60), and the giant mole-rat, Cryptomys mechowi (2n = 40), using flow-sorted painting probes representative of all but two of the H. glaber chromosomal complement. In total 43 homologous regions were identified in the C. mechowi genome. Eight H. glaber chromosomes are retained in toto in C. mechowi, and 13 produce two or more signals in this species. The most striking difference in the karyotypes of the two taxa concerns their sex chromosomes. The H. glaber painting probes identified a complex series of translocations that involved the fractionation of four autosomes and the subsequent translocation of segments to the sex chromosomes and to autosomal partners in the C. mechowi genome. An intercalary heterochromatic block (IHB) was detected in sex chromosomes of C. mechowi at the boundary with the translocated autosomal segment. We discuss the likely sequence of evolutionary events that has led to the contemporary composition of the C. mechowi sex chromosomes, and consider these in the light of prevailing views on the genesis of sex chromosomes in mammals.