Primordial germ cells: the first cell lineage or the last cells standing?

Embryos of many animal models express germ line determinants that suppress transcription and mediate early germ line commitment, which occurs before the somatic cell lineages are established. However, not all animals segregate their germ line in this manner. The ‘last cell standing’ model describes primordial germ cell (PGC) development in axolotls, in which PGCs are maintained by an extracellular signalling niche, and germ line commitment occurs after gastrulation. Here, we propose that this ‘stochastic’ mode of PGC specification is conserved in vertebrates, including non-rodent mammals. We postulate that early germ line segregation liberates genetic regulatory networks for somatic development to evolve, and that it therefore emerged repeatedly in the animal kingdom in response to natural selection. Summary: In this Hypothesis article, Johnson and Alberio propose that the determinative mechanisms for PGC specification in most model systems evolved to promote speciation and evolvability, not to maintain the germ line.

• Publication year

  2015

• Venue

  Development

• Publication date

  2015-08-15

• Fields of study

  Biology, Medicine

• Identifiers
  DOI 10.1242/dev.113993PMID 26286941PMCID 4550962
• External record

  Open on Semantic Scholar

• Source metadata

  Semantic Scholar, PubMed

• No claims are published for this paper.

• No concepts are published for this paper.

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