PUBLICATION

Zebrafish ambra1b knockout reveals a novel role for Ambra1 in primordial germ cells survival, sex differentiation and reproduction

Authors
Fontana, C.M., Terrin, F., Facchinello, N., Meneghetti, G., Dinarello, A., Gambarotto, L., Zuccarotto, A., Caichiolo, M., Brocca, G., Verin, R., Nazio, F., Carnevali, O., Cecconi, F., Bonaldo, P., Dalla Valle, L.
ID
ZDB-PUB-230429-46
Date
2023
Source
Biological research   56: 1919 (Journal)
Registered Authors
Carnevali, Oliana, Dalla Valle, Luisa, Facchinello, Nicola, Fontana, Camila Maria
Keywords
Ambra1, Mouse, PGCs, Reproduction, Sex differentiation, Zebrafish
MeSH Terms
  • Adaptor Proteins, Signal Transducing/metabolism
  • Animals
  • Female
  • Germ Cells/metabolism
  • Humans
  • Male
  • Mammals/genetics
  • Mammals/metabolism
  • Mice
  • RNA, Messenger/metabolism
  • Reproduction
  • Sex Differentiation*
  • Zebrafish*/genetics
  • Zebrafish*/metabolism
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism
(all 16)
PubMed
37106439 Full text @ Biol. Res.
Abstract
AMBRA1 is an intrinsically disordered protein, working as a scaffold molecule to coordinate, by protein-protein interaction, many cellular processes, including autophagy, mitophagy, apoptosis and cell cycle progression. The zebrafish genome contains two ambra1 paralogous genes (a and b), both involved in development and expressed at high levels in the gonads. Characterization of the zebrafish paralogous genes mutant lines generated by CRISPR/Cas9 approach showed that ambra1b knockout leads to an all-male population.
We demonstrated that the silencing of the ambra1b gene determines a reduction of primordial germ cells (PGCs), a condition that, in the zebrafish, leads to the development of all-male progeny. PGC reduction was confirmed by knockdown experiments and rescued by injection of ambra1b and human AMBRA1 mRNAs, but not ambra1a mRNA. Moreover, PGC loss was not rescued by injection with human AMBRA1 mRNA mutated in the CUL4-DDB1 binding region, thus suggesting that interaction with this complex is involved in PGC protection from loss. Results from zebrafish embryos injected with murine Stat3 mRNA and stat3 morpholino suggest that Ambra1b could indirectly regulate this protein through CUL4-DDB1 interaction. According to this, Ambra1+/- mice showed a reduced Stat3 expression in the ovary together with a low number of antral follicles and an increase of atretic follicles, indicating a function of Ambra1 in the ovary of mammals as well. Moreover, in agreement with the high expression of these genes in the testis and ovary, we found significant impairment of the reproductive process and pathological alterations, including tumors, mainly limited to the gonads.
By exploiting ambra1a and ambra1b knockout zebrafish lines, we prove the sub-functionalization between the two paralogous zebrafish genes and uncover a novel function of Ambra1 in the protection from excessive PGC loss, which seems to require binding with the CUL4-DDB1 complex. Both genes seem to play a role in the regulation of reproductive physiology.
Genes / Markers
Marker Marker Type Name
ambra1aGENEautophagy/beclin-1 regulator 1a
ambra1bGENEautophagy/beclin-1 regulator 1b
stat3GENEsignal transducer and activator of transcription 3 (acute-phase response factor)
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Figures
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Expression
Phenotype
Mutations / Transgenics
Allele Construct Type Affected Genomic Region
ia35
    Insertion
    ia36
      Small Deletion
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      Human Disease / Model
      No data available
      Sequence Targeting Reagents
      Target Reagent Reagent Type
      ambra1aMO1-ambra1aMRPHLNO
      ambra1aMO2-ambra1aMRPHLNO
      ambra1bMO1-ambra1bMRPHLNO
      ambra1bMO2-ambra1bMRPHLNO
      stat3MO1-stat3MRPHLNO
      1 - 5 of 5
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      Fish
      Antibodies
      Orthology
      No data available
      Engineered Foreign Genes
      No data available
      Mapping