Xu E Y, Moore F L, Pera R A
Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco, CA 94143-0546, USA.
Proc Natl Acad Sci U S A. 2001 Jun 19;98(13):7414-9. doi: 10.1073/pnas.131090498. Epub 2001 Jun 5.
The Deleted in AZoospermia (DAZ) genes encode potential RNA-binding proteins that are expressed exclusively in prenatal and postnatal germ cells and are strong candidates for human fertility factors. Here we report the identification of an additional member of the DAZ gene family, which we have called BOULE. With the identification of this gene, it is clear that the human DAZ gene family contains at least three members: DAZ, a Y-chromosome gene cluster that arose 30-40 million years ago and whose deletion is linked to infertility in men; DAZL, the "father" of DAZ, a gene that maps to human chromosome 3 and has homologs required for both female and male germ cell development in other organisms; and BOULE, a gene that we propose is the "grandfather" of DAZ and maps to human chromosome 2. Human and mouse BOULE resemble the invertebrate meiotic regulator Boule, the proposed ortholog of DAZ, in sequence and expression pattern and hence likely perform a similar meiotic function. In contrast, the previously identified human DAZ and DAZL are expressed much earlier than BOULE in prenatal germ stem cells and spermatogonia; DAZL also is expressed in female germ cells. These data suggest that homologs of the DAZ gene family can be grouped into two subfamilies (BOULE and DAZL) and that members of the DAZ family evolved from an ancestral meiotic regulator, Boule, to assume distinct, yet overlapping, functions in germ cell development.
无精子症缺失（DAZ）基因编码潜在的RNA结合蛋白，这些蛋白仅在产前和产后生殖细胞中表达，是人类生育因子的有力候选者。在此，我们报告了DAZ基因家族另一个成员的鉴定，我们将其命名为BOULE。随着该基因的鉴定，很明显人类DAZ基因家族至少包含三个成员：DAZ，一个位于Y染色体上的基因簇，它在3000万至4000万年前出现，其缺失与男性不育有关；DAZL，DAZ的“祖先”，一个定位于人类3号染色体的基因，在其他生物中其同源物对雌性和雄性生殖细胞发育均是必需的；以及BOULE，我们认为它是DAZ的“祖父”基因，定位于人类2号染色体。人类和小鼠的BOULE在序列和表达模式上与无脊椎动物减数分裂调节因子Boule（DAZ的推测直系同源物）相似，因此可能执行类似的减数分裂功能。相比之下，先前鉴定的人类DAZ和DAZL在产前生殖干细胞和精原细胞中的表达比BOULE早得多；DAZL也在雌性生殖细胞中表达。这些数据表明，DAZ基因家族的同源物可分为两个亚家族（BOULE和DAZL），并且DAZ家族成员从一个祖先减数分裂调节因子Boule进化而来，在生殖细胞发育中承担不同但又重叠的功能。
