Evolution of the X-specific block embedded in the human Xq21.3/Yp11.1 homology region.
Evolution of the X-specific block embedded in the human Xq21.3/Yp11.1 homology region.
复制标题
嵌入人类 Xq21.3/Yp11.1 同源区域的 X 特异性块的进化。
作者：
Vacca,M;Matarazzo,MR;Jones,J;Spalluto,C;Archidiacono,N;Ma,P;Rocchi,M;D'Urso,M;Chen,EY;D'Esposito,M;Mumm,S
Xq21.3/Yp11.1 区域代表人类性染色体之间最大的同源性片段，尽管在雄性减数分裂中没有发生重组。它可能是由 X 染色体转座到 Y 染色体而产生的。后一条染色体中目前的组织表明，同心倒位破坏了其连续性。此外，该区域中还嵌入了 X 特定块（由标记 DXS214 定义）。此前，尚未提出有关该 X 特异性片段的长度、起源或进化的假设。在这里，我们报告 X 特定块的远端边界的大小和序列的细化。此外，我们通过 FISH 实验追踪了灵长类动物中该区域的进化。这进一步阐明了 XY 同源区起源的多步机制，证明 X 特异性块在从 X 染色体初次转移后从 Y 染色体中删除。
The region Xq21.3/Yp11.1 represents the largest segment of homology between the sex chromosomes in humans, though no recombination occurs in male meiosis. It presumably arose as a transposition from the X to the Y chromosome; the present-day organization in the latter chromosome indicates a paracentric inversion that disrupted its continuity. Moreover, an X-specific block (defined by the marker DXS214) is embedded in the region. Previously, no hypotheses about the length, origin, or evolution of this X-specific segment have been proposed. Here we report on the refinement of the size and the sequence of the distal boundary of the X-specific block. Furthermore, we have tracked by FISH experiments the evolution of this region in primates. This further clarifies the multistep mechanism of origin for the XY homology region, by demonstrating that the X-specific block was deleted from the Y chromosome after the initial transfer from the X chromosome.