Church D L, Guan K L, Lambie E J
Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA.
Development. 1995 Aug;121(8):2525-35. doi: 10.1242/dev.121.8.2525.
In the germline of Caenorhabditis elegans hermaphrodites, meiotic cell cycle progression occurs in spatially restricted regions. Immediately after leaving the distal mitotic region, germ cells enter meiosis and thereafter remain in the pachytene stage of first meiotic prophase for an extended period. At the dorsoventral gonadal flexure, germ cells exit pachytene and subsequently become arrested in diakinesis. We have found that exit from pachytene is dependent on the function of three members of the MAP kinase signaling cascade. One of these genes, mek-2, is a newly identified C. elegans MEK (MAP kinase kinase). The other two genes, mpk-1/sur-1 (MAP kinase) and let-60 ras, were previously identified based on their roles in vulval induction and are shown here to act in combination with mek-2 to permit exit from pachytene. Through genetic mosaic analysis, we demonstrate that the expression of mpk-1/sur-1 is required within the germline to permit exit from pachytene.
在秀丽隐杆线虫雌雄同体的生殖系中，减数分裂细胞周期进程发生在空间受限的区域。生殖细胞在离开远端有丝分裂区域后立即进入减数分裂，此后在第一次减数分裂前期的粗线期停留较长时间。在背腹性腺弯曲处，生殖细胞退出粗线期，随后停滞在终变期。我们发现，从粗线期退出依赖于丝裂原活化蛋白激酶（MAP激酶）信号级联的三个成员的功能。其中一个基因mek-2是新鉴定出的秀丽隐杆线虫MEK（MAP激酶激酶）。另外两个基因mpk-1/sur-1（MAP激酶）和let-60 ras，先前是根据它们在外阴诱导中的作用而鉴定出来的，此处显示它们与mek-2共同作用，使生殖细胞能够退出粗线期。通过遗传镶嵌分析，我们证明生殖系内需要表达mpk-1/sur-1才能使生殖细胞退出粗线期。
