Eberhart C G, Wasserman S A
Department of Biochemistry, UT Southwestern, Dallas 75235-9038, USA.
Development. 1995 Oct;121(10):3477-86. doi: 10.1242/dev.121.10.3477.
During Drosophila spermatogenesis, germ cells undergo four rounds of mitosis, an extended premeiotic G2 phase and two meiotic divisions. In males homozygous for mutations in pelota, the germline mitotic divisions are normal, but the cell cycle arrests prior to the first meiotic division; pelota males are therefore sterile. Chromosomes begin to condense in these mutants, but other meiotic processes, including nuclear envelope breakdown and spindle formation, do not occur. The arrest phenotype closely resembles that of mutations in the Drosophila cdc25 homolog twine. Although meiosis is blocked in pelota and twine homozygotes, spermatid differentiation continues. pelota is also required for patterning in the eye and mitotic divisions in the ovary. We have cloned the pelota locus and show it encodes a 44 x 10(3) M(r) protein with yeast, plant, worm and human homologs.
在果蝇精子发生过程中，生殖细胞经历四轮有丝分裂、一个延长的减数分裂前G2期和两次减数分裂。在pelota基因突变的纯合雄性果蝇中，生殖系有丝分裂正常，但细胞周期在第一次减数分裂前停滞；因此，pelota雄性果蝇不育。在这些突变体中染色体开始浓缩，但包括核膜破裂和纺锤体形成在内的其他减数分裂过程并未发生。这种停滞表型与果蝇cdc25同源物twine基因突变的表型极为相似。虽然在pelota和twine纯合子中减数分裂受阻，但精子细胞分化仍在继续。pelota对于眼睛的模式形成和卵巢中的有丝分裂也是必需的。我们已经克隆了pelota基因座，并表明它编码一种44×10³Mr的蛋白质，该蛋白质在酵母、植物、线虫和人类中存在同源物。
