Matthews M E, Reed K C
Victorian Institute of Animal Science, Department of Agriculture, Australia.
Genomics. 1992 Aug;13(4):1267-73. doi: 10.1016/0888-7543(92)90045-t.
A 307-bp Sau3AI fragment previously cloned by deletion enrichment from the bovine Y chromosome was used to isolate a larger lambda EMBL3A genomic cattle clone. The whole 13-kb insert did not give a sex-specific pattern of hybridization to Southern blots of cattle DNA. Subclones from this phage, however, did show that this fragment had a Y-chromosomal origin. It was estimated that at least 40% of the cattle Y chromosome is composed of repeated sequences related to those within these subcloned fragments. Sequences within these subclones are male-specific or male-enriched also in sheep, goats, and deer. Comparison of cattle and sheep homologues of these sequences reveals that much greater amplification and rearrangement have occurred on the cattle Y chromosome than on the sheep Y. The apparent insertion of sequences into cattle Y-specific sequences relative to the sheep homologues suggests possible mechanisms for the evolution of the artiodactyl Y chromosome.
一个先前通过从牛Y染色体上进行缺失富集克隆得到的307 bp Sau3AI片段，被用于分离一个更大的λ EMBL3A基因组牛克隆。整个13 kb的插入片段在牛DNA的Southern印迹杂交中并未呈现性别特异性杂交模式。然而，来自该噬菌体的亚克隆显示，这个片段具有Y染色体起源。据估计，至少40%的牛Y染色体由与这些亚克隆片段内的序列相关的重复序列组成。这些亚克隆内的序列在绵羊、山羊和鹿中也是雄性特异性或雄性富集的。对这些序列的牛和绵羊同源物进行比较发现，牛Y染色体上发生的扩增和重排比绵羊Y染色体上的要多得多。相对于绵羊同源物，序列明显插入到牛Y特异性序列中，这提示了偶蹄目动物Y染色体进化的可能机制。
