In many metazoan species, germ cell formation requires the germ plasm, a specialized cytoplasm which often con-tains electron dense structures. Genes required for germ cell formation in Drosophila have been isolated p...In many metazoan species, germ cell formation requires the germ plasm, a specialized cytoplasm which often con-tains electron dense structures. Genes required for germ cell formation in Drosophila have been isolated predominantlyin screens for maternal-effect mutations. One such gene is tudor (tud); without proper tud function germ cell formationdoes not occur. Unlike other genes involved in Drosophila germ cell specification tud is dispensable for other somaticfunctions such as abdominal patterning. It is not known how TUD contributes at a molecular level to germ cell forma-tion but in tud mutants, polar granule formation is severely compromised, and mitochondrially encoded ribosomal RNAsdo not localize to the polar granule. TUD is composed of 11 repeats of the protein motif called the Tudor domain. Thereare similar proteins to TUD in the germ line of other metazoan species including mice. Probable vertebrate orthologuesof Drosophila genes involved in germ cell specification will be discussed.展开更多
文摘In many metazoan species, germ cell formation requires the germ plasm, a specialized cytoplasm which often con-tains electron dense structures. Genes required for germ cell formation in Drosophila have been isolated predominantlyin screens for maternal-effect mutations. One such gene is tudor (tud); without proper tud function germ cell formationdoes not occur. Unlike other genes involved in Drosophila germ cell specification tud is dispensable for other somaticfunctions such as abdominal patterning. It is not known how TUD contributes at a molecular level to germ cell forma-tion but in tud mutants, polar granule formation is severely compromised, and mitochondrially encoded ribosomal RNAsdo not localize to the polar granule. TUD is composed of 11 repeats of the protein motif called the Tudor domain. Thereare similar proteins to TUD in the germ line of other metazoan species including mice. Probable vertebrate orthologuesof Drosophila genes involved in germ cell specification will be discussed.