Evolution of sex chromosomes ZW of Schistosoma mansoni inferred from chromosome paint and BAC mapping analyses
Evolution of sex chromosomes ZW of Schistosoma mansoni inferred from chromosome paint and BAC mapping analyses
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DOI：
10.1016/j.parint.2012.07.007
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发表时间：
2012-12-01
影响因子：
1.9
通讯作者：
LoVerde, Philip T.
中科院分区：
文献类型：
--
作者：
Hirai, Hirohisa;Hirai, Yuriko;LoVerde, Philip T.
双殖吸虫中的寄生虫染色体具有独特的进化，因为它们表现出性染色体ZW，这在雌雄同体的其他吸虫群体中没有发现。我们进行了分子细胞遗传学分析，调查性染色体的进化，染色体涂料分析和BAC克隆定位。为了实现这一点，我们开发了一种技术，使油漆探针的基因组DNA从一个单一的刮取染色体片段使用染色体显微切割系统，和FISH定位技术的BAC克隆。油漆探针通过不同的荧光染料颜色清楚地识别了8对染色体中的每一对。结合Z/W探针染色分析和93个BAC克隆的染色体作图分析，曼氏血吸虫W染色体至少经历了4次倒位和异染色质化。93个BAC克隆中有9个与Z和W染色体都有杂交，但在Z和W染色体上的定位不同。在W异染色质化之前，通过三次倒位事件，估计同源区域已经从原始Z染色体移动到分化的W染色体。在W染色体异染色质区观察到的倒位可能发生在W异染色质化之后。这些倒位和异染色质化可能是促进S. mansoni (C)2012爱思唯尔爱尔兰有限公司保留所有权利。
Chromosomes of schistosome parasites among digenetic flukes have a unique evolution because they exhibit the sex chromosomes ZW, which are not found in the other groups of flukes that are hermaphrodites. We conducted molecular cytogenetic analyses for investigating the sex chromosome evolution using chromosome paint analysis and BAC clones mapping. To carry this out, we developed a technique for making paint probes of genomic DNA from a single scraped chromosome segment using a chromosome microdissection system, and a FISH mapping technique for BAC clones. Paint probes clearly identified each of the 8 pairs of chromosomes by a different fluorochrome color. Combination analysis of chromosome paint analysis with Z/W probes and chromosome mapping with 93 BAC clones revealed that the W chromosome of Schistosoma mansoni has evolved by at least four inversion events and heterochromatinization. Nine of 93 BAC clones hybridized with both the Z and W chromosomes, but the locations were different between Z and W chromosomes. The homologous regions were estimated to have moved from the original Z chromosome to the differentiated W chromosome by three inversions events that occurred before W heterohcromatinization. An inversion that was observed in the heterochromatic region of the W chromosome likely occurred after W heterochromatinization. These inversions and heterochromatinization are hypothesized to be the key factors that promoted the evolution of the W chromosome of S. mansoni. (C) 2012 Elsevier Ireland Ltd. All rights reserved.