PUBLICATION

Loss of Nobox prevents ovarian differentiation from juvenile ovaries in zebrafish

Authors
Qin, M., Xie, Q., Wu, K., Zhou, X., Ge, W.
ID
ZDB-PUB-220215-12
Date
2022
Source
Biology of reproduction   106(6): 1254-1266 (Journal)
Registered Authors
Ge, Wei, Qin, Mingming
Keywords
CRISPR/Cas9, Nobox, gonadal differentiation, sex reversal, zebrafish
MeSH Terms
  • Animals
  • Female
  • Male
  • Mammals/metabolism
  • Oocytes/metabolism
  • Ovarian Follicle/metabolism
  • Ovary*/metabolism
  • Sex Differentiation
  • Transcription Factors/genetics
  • Zebrafish*/genetics
  • Zebrafish*/metabolism
PubMed
35157068 Full text @ Biol. Reprod.
Abstract
As a species without master sex-determining genes, zebrafish displays high plasticity in sex differentiation, making it an excellent model for studying the regulatory mechanisms underlying gonadal differentiation and gametogenesis. Despite being a gonochorist, zebrafish is a juvenile hermaphrodite that undergoes a special phase of juvenile ovary before further differentiation into functional testis and ovary. The mechanisms underlying juvenile ovary formation and subsequent gonadal differentiation remain largely unknown. In a recent study, we demonstrated an important role for Figla (factor in the germline alpha) in zebrafish oogenesis. In this study, we explored the role of Nobox/nobox (new born ovary homeobox protein), another oocyte-specific transcription factor in females, in early zebrafish gonadogenesis using CRISPR/Cas9 technology. As in mammals, nobox is specifically expressed in zebrafish gonads with a dimorphic pattern at juvenile stage. In contrast to the mutant of figla (another oocyte-specific transcription factor), the nobox mutants showed formation of typical perinucleolar (PN) follicles at primary growth (PG) stage in juvenile gonads, suggesting occurrence of follicle assembly from cystic oocytes (chromatin nucleolar stage, CN). These follicles, however, failed to develop further to form functional ovaries, resulting in all-male phenotype. Despite its expression in adult testis, the loss of nobox did not seem to affect testis development, spermatogenesis and male spawning. In summary, our results indicate an important role for Nobox in zebrafish ovarian differentiation and early folliculogenesis.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping