Holdeman R, Nehrt S, Strome S
Department of Biology, Indiana University, Bloomington, IN 47405, USA.
Development. 1998 Jul;125(13):2457-67. doi: 10.1242/dev.125.13.2457.
A unique and essential feature of germ cells is their immortality. In Caenorhabditis elegans, germline immortality requires the maternal contribution from four genes, mes-2, mes-3, mes-4 and mes-6. We report here that mes-2 encodes a protein similar to the Drosophila Polycomb group protein, Enhancer of zeste, and in the accompanying paper that mes-6 encodes another Polycomb group protein. The Polycomb group is responsible for maintaining proper patterns of expression of the homeotic and other genes in Drosophila. It is thought that Polycomb group proteins form heteromeric complexes and control gene expression by altering chromatin conformation of target genes. As predicted from its similarity to a Polycomb group protein, MES-2 localizes to nuclei. MES-2 is found in germline nuclei in larval and adult worms and in all nuclei in early embryos. By the end of embryogenesis, MES-2 is detected primarily in the two primordial germ cells. The correct distribution of MES-2 requires the wild-type functions of mes-3 and mes-6. We hypothesize that mes-2 encodes a maternal regulator of gene expression in the early germline; its function is essential for normal early development and viability of germ cells.
生殖细胞的一个独特且重要的特征是其永生性。在秀丽隐杆线虫中，生殖系永生需要mes - 2、mes - 3、mes - 4和mes - 6这四个基因的母体贡献。我们在此报告mes - 2编码一种类似于果蝇多梳蛋白家族蛋白zeste增强子的蛋白质，并且在随附论文中报告mes - 6编码另一种多梳蛋白家族蛋白。多梳蛋白家族负责维持果蝇中同源异型基因和其他基因的正确表达模式。据认为，多梳蛋白家族蛋白形成异源复合物并通过改变靶基因的染色质构象来控制基因表达。正如从其与多梳蛋白家族蛋白的相似性所预测的那样，MES - 2定位于细胞核。在幼虫和成虫的生殖系细胞核以及早期胚胎的所有细胞核中都发现了MES - 2。到胚胎发育结束时，MES - 2主要在两个原始生殖细胞中被检测到。MES - 2的正确分布需要mes - 3和mes - 6的野生型功能。我们假设mes - 2编码早期生殖系中基因表达的母体调节因子；其功能对于生殖细胞的正常早期发育和生存能力至关重要。
