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ZFIN ID: ZDB-PUB-130201-18
Germ cells are required to maintain a stable sexual phenotype in adult zebrafish
Dranow, D.B., Tucker, R.P., and Draper, B.W.
Date: 2013
Source: Developmental Biology   376(1): 43-50 (Journal)
Registered Authors: Draper, Bruce
Keywords: gem cells, oocyte, sex determination
MeSH Terms:
  • Animals
  • Base Sequence
  • Cloning, Molecular
  • Female
  • Gene Expression Regulation/physiology*
  • Germ Cells/cytology
  • Germ Cells/metabolism*
  • Histological Techniques
  • Immunohistochemistry
  • In Situ Hybridization
  • Male
  • Metronidazole
  • Models, Biological
  • Molecular Sequence Data
  • Phenotype*
  • Plasmids/genetics
  • Sex Determination Processes/physiology*
  • Signal Transduction/physiology*
  • Stem Cells/cytology
  • Stem Cells/metabolism*
  • Zebrafish/embryology*
PubMed: 23348677 Full text @ Dev. Biol.

Sex in zebrafish is not determined by a major chromosomal locus, but instead relies on a mechanism that is influenced by a germ cell-derived signal, as animals that lack germ cells, or specifically oocytes, develop as phenotypic males. These data suggest that during primary sex determination, an oocyte-derived signal acts on the bipotential somatic gonad to promote the female-specific program. However, it is not known if germ cells are required only during the primary sex-determining window, or if they are required throughout adult life to maintain the female sexual phenotype. Here, we show that while wild-type zebrafish do not switch sex as adults, germ cell-depleted adult females readily convert to a male phenotype. Notably, when oocytes are depleted, but germline stem cells remain, adult females revert to sperm-producing males, indicating that a germ cell-derived signal acts on the somatic gonad to promote female development directly or indirectly by repressing male-specific gene expression. These results also confirm that signals from the somatic gonad in turn ensure that the sex appropriate gamete is produced.