PUBLICATION

Disruption of Epidermal Growth Factor Receptor but Not EGF Blocks Follicle Activation in Zebrafish Ovary

Authors
Song, Y., Chen, W., Zhu, B., Ge, W.
ID
ZDB-PUB-220204-3
Date
2022
Source
Frontiers in cell and developmental biology   9: 750888 (Journal)
Registered Authors
Chen, Weiting, Ge, Wei
Keywords
EGF receptor EGFR, epidermal growth factor EGF, folliculogenesis, gonadal development, spermatogenesis, zebrafish
MeSH Terms
none
PubMed
35111746 Full text @ Front Cell Dev Biol
Abstract
Folliculogenesis is controlled by intimate communications between oocytes and surrounding follicle cells. Epidermal growth factor (EGF/Egf) is an important paracrine/autocrine factor in vertebrate ovary, and it is well known for its stimulation of oocyte maturation. However, the role of EGF signaling through its receptor (EGFR/Egfr) in ovarian folliculogenesis is poorly understood, especially at early stages of follicle development. In this study, we created zebrafish mutants for Egf (egf-/- ) and Egfr (egfra-/- and egfrb-/- ) by CRISPR/Cas9 technique. Surprisingly, these mutants all survived well with little abnormality in growth and development. Spermatogenesis and folliculogenesis were both normal in egf-/- males and females. Their fecundity was comparable to that of the wildtype fish at 4 months post-fertilization (mpf); however, the fertilization rate of mutant eggs (egf-/- ) decreased significantly at 7 mpf. Interestingly, disruption of egfra (egfra-/- ) led to failed follicle activation with folliculogenesis being blocked at primary-secondary growth transition (PG-SG transition), leading to female infertility, whereas the mutant males remained fertile. The mutant ovary (egfra-/- ) showed abnormal expression of a substantial number of genes involved in oxidative metabolism, gene transcription, cytomembrane transport, steroid hormone biosynthesis, and immune response. The stunted PG oocytes in egfra-/- ovary eventually underwent degeneration after 6 months followed by sex reversal to males with functional testes. No abnormal phenotypes were found in the mutant of truncated form of EGFR (egfrb). In summary, our data revealed critical roles for EGFR signaling in early folliculogenesis, especially at the PG-SG transition or follicle activation.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Allele Construct Type Affected Genomic Region
umo19
    Indel
    umo20
      Indel
      umo21
        Small Deletion
        umo22
          Small Deletion
          1 - 4 of 4
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          Human Disease / Model
          No data available
          Sequence Targeting Reagents
          No data available
          Fish
          Antibodies
          Name Type Antigen Genes Isotypes Host Organism
          Ab9-mapkmonoclonal
            IgGRabbit
            1 - 1 of 1
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            Orthology
            No data available
            Engineered Foreign Genes
            No data available
            Mapping
            No data available