Early Depletion of Primordial Germ Cells in Zebrafish Promotes Testis Formation

Stem Cell Reports. 2015 Jan 13;4(1):61-73. doi: 10.1016/j.stemcr.2014.10.011. Epub 2014 Nov 26.

Abstract

As complete absence of germ cells leads to sterile males in zebrafish, we explored the relationship between primordial germ cell (PGC) number and sexual development. Our results revealed dimorphic proliferation of PGCs in the early zebrafish larvae, marking the beginning of sexual differentiation. We applied morpholino-based gene knockdown and cell transplantation strategies to demonstrate that a threshold number of PGCs is required for the stability of ovarian fate. Using histology and transcriptomic analyses, we determined that zebrafish gonads are in a meiotic ovarian stage at 14 days postfertilization and identified signaling pathways supporting meiotic oocyte differentiation and eventual female fate. The development of PGC-depleted gonads appears to be restrained and delayed, suggesting that PGC number may directly regulate the variability and length of gonadal transformation and testicular differentiation in zebrafish. We propose that gonadal transformation may function as a developmental buffering mechanism to ensure the reproductive outcome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cell Differentiation
  • Cell Proliferation
  • Cluster Analysis
  • Embryo, Nonmammalian
  • Female
  • Gene Expression Profiling
  • Germ Cells / cytology*
  • Germ Cells / metabolism*
  • Gonads / cytology
  • Gonads / embryology*
  • Gonads / metabolism*
  • Larva
  • Male
  • Meiosis
  • Models, Biological
  • Reproducibility of Results
  • Sex Characteristics
  • Sex Differentiation
  • Signal Transduction
  • Time Factors
  • Transcriptome
  • Transforming Growth Factor beta / metabolism
  • Zebrafish / embryology*
  • Zebrafish / genetics
  • Zebrafish / metabolism*

Substances

  • Transforming Growth Factor beta

Associated data

  • GEO/GSE57046