PUBLICATION

Zebrafish monosex population reveals female dominance in sex determination and earliest events of gonad differentiation

Authors
Tong, S.K., Hsu, H.J., and Chung, B.C.
ID
ZDB-PUB-100621-31
Date
2010
Source
Developmental Biology   344(2): 849-856 (Journal)
Registered Authors
Chung, Bon-chu
Keywords
Juvenile, Testis, Ovary, Germ cells, Somatic cell, Male
MeSH Terms
  • Animals
  • Cell Differentiation
  • Female
  • Germ Cells
  • Gonads/growth & development*
  • Gonads/metabolism*
  • Male
  • Methyltestosterone/metabolism
  • Ovary
  • Sex Differentiation
  • Zebrafish/genetics*
  • Zebrafish/growth & development*
PubMed
20553901 Full text @ Dev. Biol.
Abstract
The zebrafish is a popular model for genetic analysis and its sex differentiation has been the focus of attention for breeding purposes. Despite numerous efforts, very little is known about the mechanism of zebrafish sex determination. The lack of discernible sex chromosomes and the difficulty of distinguishing the sex of juvenile fish are two major obstacles that hamper the progress in such studies. To alleviate these problems, we have developed a scheme involving methyltestosterone treatment followed by natural mating to generate fish with predictable sex trait. Female F1 fish that gave rise to all-female offspring were generated. This predictable sex trait enables characterization of gonadal development in juvenile fish by histological examination and gene expression analysis. We found the first sign of zebrafish sex differentiation to be ovarian gonocyte proliferation and differentiation at 10-12days post-fertilization (dpf). Somatic genes were expressed indifferently at 10 to 17dpf, and then became sexually dimorphic at three weeks. This result indicates clear distinction of male and female gonads derived independently from primordial gonads. We classified the earliest stages of zebrafish sex determination into the initial preparation followed by female germ cell growth, oocyte differentiation, and somatic differentiation. Our genetic selection scheme matches the prediction that female-dominant genetic factors are required to determine zebrafish sex.
Genes / Markers
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping