title: Cyclin E2 is required for embryogenesis in Xenopus laevis.
abstract: In mammalian cells, E-type cyclins (E1 and E2) are generally believed to be required for entry into S phase. However, in mice, cyclin E is largely dispensable for normal embryogenesis. Moreover, Drosophila cyclin E plays a critical role in cell fate determination in neural lineages independently of proliferation. Thus, the functions of cyclin E, particularly during early development, remain elusive. Here, we investigated the requirement for E-type cyclins during Xenopus embryogenesis. Although cyclin E1 has been reported as a maternal cyclin, inhibition of its translation in the embryo caused no serious defects. We isolated a Xenopus homologue of human cyclin E2, which was zygotically expressed. Sufficient inhibition of its expression led to death at late gastrula, while partial inhibition allowed survival. These observations indicate distinct roles for Xenopus cyclins E1 and E2, and an absolute requirement of cyclin E2 for Xenopus embryogenesis.
authors.affiliation: Laboratory of Cell and Developmental Biology, Graduate School of Bioscience, Tokyo Institute of Technology, Nagatsuta 4259, Yokohama, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Gotoh
authors.forename: Noriko
authors.initials: N
authors.lastname: Shigemoto
authors.forename: Takeo
authors.initials: T
authors.lastname: Kishimoto
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016213:Cyclins / Q000235:genetics / Q000502:physiology*; D005775:Gastrula / Q000502:physiology; D008969:Molecular Sequence Data; D029867:Xenopus Proteins / Q000235:genetics / Q000502:physiology*; D014982:Xenopus laevis / Q000196:embryology* / Q000378:metabolism