1. C. Courtot, C. Fankhauser, V. Simanis and C. F. Lehner (1992) The Drosophila cdc25 homolog twine is required for meiosis. Development 116(2): 405-16.
Abstract We have identified a second cdc25 homolog in Drosophila. In contrast to string (the first homolog identified in Drosophila) this second homolog, twine, does not function in the mitotic cell cycle, but is specialized for meiosis. Expression of twine was observed exclusively in male and female gonads. twine transcripts are present in germ cells during meiosis, and appear only late during gametogenesis, well after the end of the mitotic germ cell divisions. The sterile Drosophila mutant, mat(2)synHB5, which had previously been isolated and mapped to the same genomic region as twine (35F), was found to carry a missense mutation in the twine gene. This missense mutation in twine abolished its ability to complement a mutation in Schizosaccharomyces pombe cdc25. Phenotypic analysis of mat(2)synHB5 mutant flies revealed a complete block of meiosis in males and severe meiotic defects in females. PMID: [1286615]
2. S. Sigrist, G. Ried and C. F. Lehner (1995) Dmcdc2 kinase is required for both meiotic divisions during Drosophila spermatogenesis and is activated by the Twine/cdc25 phosphatase. Mech Dev 53(2): 247-60.
Abstract We have analyzed the requirement for Drosophila cdc2 kinase during spermatogenesis after generating temperature-sensitive mutant lines (Dmcdc2ts) by re-constructing mutations known to result in temperature sensitivity in fission yeast cdc2+. While meiotic spindles and metaphase plates were never formed in Dmcdc2ts mutants at high temperature, chromosomes still condensed in late spermatocytes and spermatid differentiation (sperm head and tail formation) continued. The same phenotype was also observed in twine and twine, Dmcdc2ts double mutant testes, consistent with the idea that the cdc2 kinase activity required for meiotic divisions is activated by the Twine/cdc25 phosphatase. Confirming this notion, we find that ectopic expression of the String/cdc25 phosphatase, which is known to activate the cdc2 kinase before mitosis, results in a partial rescue of meiotic divisions in twine mutant testis. PMID: [8562426]
CHAIN 1 426 Cdc25-like protein phosphatase twine. /FTId=PRO_0000198659. DOMAIN 265 371 Rhodanese. ACT_SITE 318 318 By similarity. CONFLICT 48 48 L -> M (in Ref. 6; CAA48783). Back to Top