title: Temporal and spatial expression patterns of Cdc25 phosphatase isoforms during early Xenopus development.
abstract: In early animal development, cell proliferation and differentiation are tightly linked and coordinated. It is important, therefore, to know how the cell cycle is controlled during early development. Cdc25 phosphatases activate cyclin-dependent kinases (Cdks) and thereby promote cell-cycle progression. In Xenopus laevis, three isoforms of cdc25 have been identified, viz. cdc25A, cdc25B and cdc25C. In this study, we isolated a cDNA encoding a novel Xenopus Cdc25 phosphatase (named cdc25D). We investigated the temporal and spatial expression patterns of the four cdc25 isoforms during early Xenopus development, using RT-PCR and whole-mount in situ hybridization. cdc25A and cdc25C were expressed both maternally and zygotically, whereas cdc25B and cdc25D were expressed zygotically. Both cdc25A and cdc25C were expressed mainly in prospective neural regions, whereas cdc25B was expressed preferentially in the central nervous system (CNS), such as the spinal cord and the brain. Interestingly, cdc25D was expressed in the epidermal ectoderm of the late-neurula embryo, and in the liver diverticulum endoderm of the mid-tailbud embryo. In agreement with the spatial expression patterns in whole embryos, inhibition of bone morphoge- netic protein (BMP), a crucial step for neural induction, induced an upregulation of cdc25B, but a downregulation of cdc25D in animal cap assays.These results indicate that different cdc25 isoforms are differently expressed and play different roles during early Xenopus development.
authors.affiliation: Department of Biology, Graduate School of Sciences, Kyushu University, Fukuoka, Japan. nnakascb@kyushu-u.org
authors.forename: Nobushige
authors.initials: N
authors.lastname: Nakajo
authors.forename: Yu-Ki
authors.initials: YK
authors.lastname: Deno
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ueno
authors.forename: Chihiro
authors.initials: C
authors.lastname: Kenmochi
authors.forename: Ken
authors.initials: K
authors.lastname: Shimuta
authors.forename: Noriyuki
authors.initials: N
authors.lastname: Sagata
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000378:metabolism; D002453:Cell Cycle; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D049109:Cell Proliferation; D002490:Central Nervous System / Q000196:embryology; D018844:Cyclin-Dependent Kinases / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000378:metabolism*; D047108:Embryonic Development; D018507:Gene Expression Regulation, Developmental; D020033:Protein Isoforms / Q000235:genetics* / Q000378:metabolism; D020539:Sequence Analysis, Protein; D029867:Xenopus Proteins / Q000235:genetics / Q000378:metabolism; D014982:Xenopus laevis / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D020687:cdc25 Phosphatases / Q000235:genetics* / Q000378:metabolism
chemical_list: D019485:Bone Morphogenetic Proteins; D018797:Cell Cycle Proteins; D020033:Protein Isoforms; D029867:Xenopus Proteins; D018844:Cyclin-Dependent Kinases; C102266:Cdc25A protein, Xenopus; D020687:cdc25 Phosphatases