The amelogenin loci span an ancient pseudoautosomal boundary in diverse mammalian species
The amelogenin loci span an ancient pseudoautosomal boundary in diverse mammalian species
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DOI：
10.1073/pnas.0635848100
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发表时间：
2003-04-29
影响因子：
11.1
通讯作者：
Takahata, N
中科院分区：
文献类型：
--
作者：
Iwase, M;Satta, Y;Takahata, N
哺乳动物釉原蛋白(AMEL)基因存在于X和Y染色体上(配子体)。对五种灵长类和其他三种哺乳动物的基因组AMEL序列的比较表明，配子体AMEL基因座的5‘部分开始分化。现存哺乳动物的共同祖先，而3‘端部分在不同哺乳动物的物种内独立分化。这一边界由内含子2中的转座子插入标记，并被所有被研究的物种所共享。此外，来自人类X染色体短臂的540kb DNA序列与其Y配子体序列进行了比对。AMEL基因座5‘端的序列差异模式和范围延伸到包含ZFX基因座的近端区域，而3’端的序列差异一直延伸到伪常染色体边界(PAB)1。我们得出结论：AMEL基因座跨越一个古老的PAB，古代和现在的PAB都是由哺乳动物和灵长类进化过程中的偶然事件决定的。性染色体分化可能发生在通过抑制同源重组而包含男性决定基因的区域。
The mammalian amelogenin (AMEL) genes are found on both the X and Y chromosomes (gametologous). Comparison of the genomic AMEL sequences in five primates and three other mammals reveals that the 5' portion of the gametologous AMEL loci began to differentiate in the. common ancestor of extant mammals, whereas the 3' portion differentiated independently within species of different mammals. The boundary is marked by a transposon insertion in intron 2 and is shared by all species examined. In addition, 540-kb DNA sequences from the short arm of the human X chromosome are aligned with their Y gametologous sequences. The pattern and extent of sequence differences in the 5' portion of the AMEL loci extend to a proximal region that contains the ZFX locus, and those in the 3' portion extend all the way down to the pseudoautosomal boundary (PAB)1. We concluded that the AMEL locus spans an ancient PAB, and that both the ancient and present PABs were determined by chance events during the evolution of mammals and primates. Sex chromosome differentiation likely took place in a region that contains the male-determining loci by suppressing homologous recombination.