Selective accumulation of germ-line associated gene products in early development of the sea star and distinct differences from germ-line development in the sea urchin

Dev Dyn. 2014 Apr;243(4):568-87. doi: 10.1002/dvdy.24038. Epub 2013 Dec 25.


Background: Echinodermata is a diverse phylum, a sister group to chordates, and contains diverse organisms that may be useful to understand varied mechanisms of germ-line specification.

Results: We tested 23 genes in development of the sea star Patiria miniata that fall into five categories: (1) Conserved germ-line factors; (2) Genes involved in the inductive mechanism of germ-line specification; (3) Germ-line associated genes; (4) Molecules involved in left-right asymmetry; and (5) Genes involved in regulation and maintenance of the genome during early embryogenesis. Overall, our results support the contention that the posterior enterocoel is a source of the germ line in the sea star P. miniata.

Conclusions: The germ line in this organism appears to be specified late in embryogenesis, and in a pattern more consistent with inductive interactions amongst cells. This is distinct from the mechanism seen in sea urchins, a close relative of the sea star clad. We propose that P. miniata may serve as a valuable model to study inductive mechanisms of germ-cell specification and when compared with germ-line formation in the sea urchin S. purpuratus may reveal developmental transitions that occur in the evolution of inherited and inductive mechanisms of germ-line specification.

Keywords: echinoderm; germ line; inductive germ-cell determination; posterior enterocoel.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Embryo, Nonmammalian* / cytology
  • Embryo, Nonmammalian* / embryology
  • Germ Cells* / cytology
  • Germ Cells* / metabolism
  • Models, Biological*
  • Sea Urchins* / cytology
  • Sea Urchins* / embryology
  • Species Specificity
  • Starfish* / cytology
  • Starfish* / embryology