© Springer International Publishing Switzerland 2017 383
F. Pelegri et al. (eds.), Vertebrate Development, Advances in Experimental
Medicine and Biology 953, DOI 10.1007/978-3-319-46095-6_8
Chapter 8
Mechanisms of Vertebrate Germ Cell
Determination
Tristan Aguero, Susannah Kassmer, Ramiro Alberio, Andrew Johnson,
and Mary Lou King
Abstract Two unique characteristics of the germ line are the ability to persist from
generation to generation and to retain full developmental potential while differenti-
ating 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 develop-
ment of solitary and colonial ascidians to provide an evolutionary context to both
mechanisms. We conclude with a discussion of the inductive mechanism as exem-
plified 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.
Keywords Germ line primordial germ cells • Zebrafish • Xenopus • Ascidians •
Mouse • Axolotl • Cell-autonomous • Inductive • Gene network or genetics
T. Aguero • M.L. King (*)
Department of Cell Biology, University of Miami, Miller School of Medicine,
Miami, FL, USA
e-mail: [email protected]; [email protected]
S. Kassmer
Molecular, Cellular and Developmental Biology, University of California,
Santa Barbara, CA, USA
e-mail: [email protected]
R. Alberio
School of Biosciences, University of Nottingham, Nottingham LE12 5RD, UK
e-mail: [email protected]
A. Johnson
School of Life Sciences, University of Nottingham, Queen’s Medical Centre,
Nottingham NG7 2UH, UK
e-mail: [email protected]