Drosophila Cyclin B3 is required for female fertility and is dispensable for mitosis like Cyclin B.
Cyclin B3 has been conserved during higher eukaryote evolution as evidenced by its identification in chicken, nematodes, and insects. We demonstrate that Cyclin B3 is present in addition to Cyclins A and B in mitotically proliferating cells and not detectable in endoreduplicating tissues of Drosophila embryos. Cyclin B3 is coimmunoprecipitated with Cdk1(Cdc2) but not with Cdk2(Cdc2c). It is degraded abruptly during mitosis like Cyclins A and B. In contrast to these latter cyclins, which accumulate predominantly in the cytoplasm during interphase, Cyclin B3 is a nuclear protein. Genetic analyses indicate functional redundancies. Double and triple mutant analyses demonstrate that Cyclins A, B, and B3 cooperate to regulate mitosis, but surprisingly single mutants reveal that neither Cyclin B3 nor Cyclin B is required for mitosis. However, both are required for female fertility and Cyclin B also for male fertility.
Jacobs
H W
HW
Department of Genetics, University of Bayreuth, 95440 Bayreuth, Germany.
Knoblich
J A
JA
Lehner
C F
CF
D000595:Amino Acid Sequence; D000818:Animals; D016203:CDC2 Protein Kinase / Q000378:metabolism; D002451:Cell Compartmentation; D002467:Cell Nucleus / Q000378:metabolism; D019925:Cyclin A / Q000235:genetics / Q000378:metabolism; D019926:Cyclin B / Q000235:genetics / Q000378:metabolism*; D004330:Drosophila / Q000196:embryology*; D029721:Drosophila Proteins; D005260:Female; D005298:Fertility; D008297:Male; D008938:Mitosis; D008969:Molecular Sequence Data; D009154:Mutation; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D010063:Ovum / Q000378:metabolism*; D011485:Protein Binding; D017386:Sequence Homology, Amino Acid
C503698:CycB protein, Drosophila; D019925:Cyclin A; D019926:Cyclin B; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D016203:CDC2 Protein Kinase