Meiotic chromosomes and stages of sex chromosome evolution in fish: zebrafish, platyfish and guppy
Meiotic chromosomes and stages of sex chromosome evolution in fish: zebrafish, platyfish and guppy
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DOI：
10.1023/a:1012956324417
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发表时间：
2004
影响因子：
2.6
通讯作者：
W. Traut;H. Winking
中科院分区：
文献类型：
--
作者：
W. Traut;H. Winking
我们描述了SC补体和比较基因组杂交（CGH）的有丝分裂和减数分裂染色体的斑马鱼，斑剑尾鱼和孔雀鱼。这三种鱼类代表性染色体分化的基本步骤：（1）斑马鱼具有全常染色体核型;（2）具有遗传定义的性染色体，但在SC中没有可见的X和Y之间的分化，或在减数分裂和有丝分裂染色体中具有CGH;（3）具有遗传和细胞遗传分化的性染色体的孔雀鱼。孔雀鱼的Y染色体由近端同源片段和远端差异片段组成。近节在粗线期早期与相应的X染色体节配对。差异段在粗线期早期是不成对的，但在“调整”或“均衡”过程中突触较晚。该片段包括一个假定的性别决定区和一个明显的可变异染色质区，其结构取决于特定的Y染色体系。CGH区分了该区域中主要是男性特异性重复DNA的大块和常见重复DNA的块。
We describe SC complements and results from comparative genomic hybridization (CGH) on mitotic and meiotic chromosomes of the zebrafishDanio rerio, the platyfishXiphophorus maculatusand the guppyPoecilia reticulata. The three fish species represent basic steps of sex chromosome differentiation: (1) the zebrafish with an all-autosome karyotype; (2) the platyfish with genetically defined sex chromosomes but no differentiation between X and Y visible in the SC or with CGH in meiotic and mitotic chromosomes; (3) the guppy with genetically and cytogenetically differentiated sex chromosomes. The acrocentric Y chromosomes of the guppy consists of a proximal homologous and a distal differential segment. The proximal segment pairs in early pachytene with the respective X chromosome segment. The differential segment is unpaired in early pachytene but synapses later in an ‘adjustment’ or ‘equalization’ process. The segment includes a postulated sex determining region and a conspicuous variable heterochromatic region whose structure depends on the particular Y chromosome line. CGH differentiates a large block of predominantly male-specific repetitive DNA and a block of common repetitive DNA in that region.