Toder R, Graves J A
School of Genetics and Human Variation, La Trobe University, Bundoora, Melbourne, Vic 3083, Australia.
Mamm Genome. 1998 May;9(5):373-6. doi: 10.1007/s003359900772.
The X and Y Chromosomes (Chrs) of eutherian ("placental") mammals share a pseudo-autosomal region (PAR) that pairs and recombines at meiosis. In humans and other eutherians, the PAR contains several active genes and has also been thought to be critical for pairing and fertility. In order to explore the origin of the PAR, we cloned and mapped three human or mouse pseudoautosomal genes in marsupials, a group of mammals that diverged from eutherians about 130 (MYrBP). All three genes were autosomal in marsupials, and two co-localized with other human Xp genes on an autosome. This implies that the human PAR, like most of human Xp, represents a relic of an autosomal region added to both X and Y Chrs between 80 and 150 MYrBP.
真兽亚纲（“有胎盘”）哺乳动物的X和Y染色体共享一个在减数分裂时配对并重组的假常染色体区域（PAR）。在人类和其他真兽亚纲动物中，PAR包含几个活性基因，并且一直被认为对配对和生育能力至关重要。为了探究PAR的起源，我们克隆并定位了有袋类动物中的三个人类或小鼠假常染色体基因，有袋类是一类大约在1.3亿年前（百万年前）从真兽亚纲分化出来的哺乳动物。这三个基因在有袋类动物中都是常染色体基因，并且其中两个与其他人类Xp基因共定位于一条常染色体上。这意味着人类PAR，就像大多数人类Xp一样，代表了一个在8000万至1.5亿年前添加到X和Y染色体上的常染色体区域的遗迹。
