title: The Xenopus Maternal-to-Zygotic Transition from the Perspective of the Germline.
abstract: In Xenopus, the germline is specified by the inheritance of germ-plasm components synthesized at the beginning of oogenesis. Only the cells in the early embryo that receive germ plasm, the primordial germ cells (PGCs), are competent to give rise to the gametes. Thus, germ-plasm components continue the totipotent potential exhibited by the oocyte into the developing embryo at a time when most cells are preprogrammed for somatic differentiation as dictated by localized maternal determinants. When zygotic transcription begins at the mid-blastula transition, the maternally set program for somatic differentiation is realized. At this time, genetic control is ceded to the zygotic genome, and developmental potential gradually becomes more restricted within the primary germ layers. PGCs are a notable exception to this paradigm and remain transcriptionally silent until the late gastrula. How the germ-cell lineage retains full potential while somatic cells become fate restricted is a tale of translational repression, selective degradation of somatic maternal determinants, and delayed activation of zygotic transcription.
authors.affiliation: Department of Comparative Biosciences, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.affiliation: Department of Cell Biology, University of Miami, Miller School of Medicine, Miami, Florida, USA.
authors.forename: Tristan
authors.initials: T
authors.lastname: Aguero
authors.affiliation: Department of Cell Biology, University of Miami, Miller School of Medicine, Miami, Florida, USA. Electronic address: mking@med.miami.edu.
authors.forename: Mary Lou
authors.initials: ML
authors.lastname: King
mesh_terms: D000818:Animals; D019070:Cell Lineage; D003599:Cytoskeleton / Q000378:metabolism; D005260:Female; D005854:Germ Cells / Q000502:physiology*; D020871:RNA Stability; D014981:Xenopus / Q000196:embryology*; D015053:Zygote / Q000502:physiology*
keywords: Germ plasm; Mid-blastula transition; Primordial germ cells; Pumilio; Xenopus