title: Mechanisms of Vertebrate Germ Cell Determination.
abstract: Two unique characteristics of the germ line are the ability to persist from generation to generation and to retain full developmental potential while differentiating into gametes. How the germ line is specified that allows it to retain these characteristics within the context of a developing embryo remains unknown and is one focus of current research. Germ cell specification proceeds through one of two basic mechanisms: cell autonomous or inductive. Here, we discuss how germ plasm driven germ cell specification (cell autonomous) occurs in both zebrafish and the frog Xenopus. We describe the segregation of germ cells during embryonic development of solitary and colonial ascidians to provide an evolutionary context to both mechanisms. We conclude with a discussion of the inductive mechanism as exemplified by both the mouse and axolotl model systems. Regardless of mechanism, several general themes can be recognized including the essential role of repression and posttranscriptional regulation of gene expression.
authors.affiliation: Department of Cell Biology, University of Miami, Miller School of Medicine, Miami, FL, USA.
authors.forename: Tristan
authors.initials: T
authors.lastname: Aguero
authors.affiliation: Molecular, Cellular and Developmental Biology, University of California, Santa Barbara, CA, USA.
authors.forename: Susannah
authors.initials: S
authors.lastname: Kassmer
authors.affiliation: School of Biosciences, University of Nottingham, Nottingham, LE12 5RD, UK.
authors.forename: Ramiro
authors.initials: R
authors.lastname: Alberio
authors.affiliation: School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, NG7 2UH, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Johnson
authors.affiliation: Department of Cell Biology, University of Miami, Miller School of Medicine, Miami, FL, USA. mking@med.miami.edu.
authors.forename: Mary Lou
authors.initials: ML
authors.lastname: King
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000235:genetics*; D047108:Embryonic Development / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D053263:Gene Regulatory Networks / Q000235:genetics*; D005854:Germ Cells / Q000254:growth & development* / Q000378:metabolism; D051379:Mice; D014981:Xenopus / Q000254:growth & development; D014982:Xenopus laevis / Q000254:growth & development; D015027:Zebrafish / Q000254:growth & development
keywords: Ascidians; Axolotl; Cell-autonomous; Gene network or genetics; Germ line primordial germ cells; Inductive; Mouse; Xenopus; Zebrafish