The piRNA protein Asz1 is essential for germ cell and gonad development in zebrafish and exhibits differential necessities in distinct types of germ granules.

Germ cells are essential for fertility, embryogenesis, and reproduction. Germline development requires distinct types of germ granules, which contains RNA-protein (RNP) complexes, including germ plasm in embryos, piRNA granules in gonadal germ cells, and the Balbiani body (Bb) in oocytes. However, t...

Full description

Saved in:
Bibliographic Details
Main Authors: Adam Ahmad, Yoel Bogoch, Gal Shvaizer, Noga Guler, Karine Levy, Yaniv M Elkouby
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2025-01-01
Series:PLoS Genetics
Online Access:https://doi.org/10.1371/journal.pgen.1010868
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1832542647850369024
author Adam Ahmad
Yoel Bogoch
Gal Shvaizer
Noga Guler
Karine Levy
Yaniv M Elkouby
author_facet Adam Ahmad
Yoel Bogoch
Gal Shvaizer
Noga Guler
Karine Levy
Yaniv M Elkouby
author_sort Adam Ahmad
collection DOAJ
description Germ cells are essential for fertility, embryogenesis, and reproduction. Germline development requires distinct types of germ granules, which contains RNA-protein (RNP) complexes, including germ plasm in embryos, piRNA granules in gonadal germ cells, and the Balbiani body (Bb) in oocytes. However, the regulation of RNP assemblies in zebrafish germline development are still poorly understood. Asz1 is a piRNA protein in Drosophila and mice. Zebrafish Asz1 localizes to both piRNA and Bb granules, with yet unknown functions. Here, we hypothesized that Asz1 functions in germ granules and germline development in zebrafish. We generated asz1 mutant fish to determine the roles of Asz1 in germ cell development. We show that Asz1 is dispensable for somatic development, but essential for germ cell and gonad development. asz1-/- fish developed exclusively as sterile males with severely underdeveloped testes that lacked germ cells. In asz1 mutant juvenile gonads, germ cells undergo extensive apoptosis, demonstrating that Asz1 is essential for germ cell survival. Mechanistically, we provide evidence to conclude that zygotic Asz1 is not required for primordial germ cell specification or migration to the gonad, but is essential during post-embryonic gonad development, likely by suppressing the expression of germline transposons. Increased transposon expression and mis-organized piRNA granules in asz1 mutants, argue that zebrafish Asz1 functions in the piRNA pathway. We generated asz1;tp53 fish to partially rescue ovarian development, revealing that Asz1 is also essential for oogenesis. We further showed that in contrast with piRNA granules, Asz1 is dispensable for Bb granule formation, as shown by normal Bb localization of Buc and dazl. By uncovering Asz1 as an essential regulator of germ cell survival and gonadogenesis in zebrafish, and determining its differential necessity in distinct germ granule types, our work advances our understanding of the developmental genetics of reproduction and fertility, as well as of germ granule biology.
format Article
id doaj-art-4dc6bfd8ff704a8fad70fa33ecfce135
institution Kabale University
issn 1553-7390
1553-7404
language English
publishDate 2025-01-01
publisher Public Library of Science (PLoS)
record_format Article
series PLoS Genetics
spelling doaj-art-4dc6bfd8ff704a8fad70fa33ecfce1352025-02-03T21:31:07ZengPublic Library of Science (PLoS)PLoS Genetics1553-73901553-74042025-01-01211e101086810.1371/journal.pgen.1010868The piRNA protein Asz1 is essential for germ cell and gonad development in zebrafish and exhibits differential necessities in distinct types of germ granules.Adam AhmadYoel BogochGal ShvaizerNoga GulerKarine LevyYaniv M ElkoubyGerm cells are essential for fertility, embryogenesis, and reproduction. Germline development requires distinct types of germ granules, which contains RNA-protein (RNP) complexes, including germ plasm in embryos, piRNA granules in gonadal germ cells, and the Balbiani body (Bb) in oocytes. However, the regulation of RNP assemblies in zebrafish germline development are still poorly understood. Asz1 is a piRNA protein in Drosophila and mice. Zebrafish Asz1 localizes to both piRNA and Bb granules, with yet unknown functions. Here, we hypothesized that Asz1 functions in germ granules and germline development in zebrafish. We generated asz1 mutant fish to determine the roles of Asz1 in germ cell development. We show that Asz1 is dispensable for somatic development, but essential for germ cell and gonad development. asz1-/- fish developed exclusively as sterile males with severely underdeveloped testes that lacked germ cells. In asz1 mutant juvenile gonads, germ cells undergo extensive apoptosis, demonstrating that Asz1 is essential for germ cell survival. Mechanistically, we provide evidence to conclude that zygotic Asz1 is not required for primordial germ cell specification or migration to the gonad, but is essential during post-embryonic gonad development, likely by suppressing the expression of germline transposons. Increased transposon expression and mis-organized piRNA granules in asz1 mutants, argue that zebrafish Asz1 functions in the piRNA pathway. We generated asz1;tp53 fish to partially rescue ovarian development, revealing that Asz1 is also essential for oogenesis. We further showed that in contrast with piRNA granules, Asz1 is dispensable for Bb granule formation, as shown by normal Bb localization of Buc and dazl. By uncovering Asz1 as an essential regulator of germ cell survival and gonadogenesis in zebrafish, and determining its differential necessity in distinct germ granule types, our work advances our understanding of the developmental genetics of reproduction and fertility, as well as of germ granule biology.https://doi.org/10.1371/journal.pgen.1010868
spellingShingle Adam Ahmad
Yoel Bogoch
Gal Shvaizer
Noga Guler
Karine Levy
Yaniv M Elkouby
The piRNA protein Asz1 is essential for germ cell and gonad development in zebrafish and exhibits differential necessities in distinct types of germ granules.
PLoS Genetics
title The piRNA protein Asz1 is essential for germ cell and gonad development in zebrafish and exhibits differential necessities in distinct types of germ granules.
title_full The piRNA protein Asz1 is essential for germ cell and gonad development in zebrafish and exhibits differential necessities in distinct types of germ granules.
title_fullStr The piRNA protein Asz1 is essential for germ cell and gonad development in zebrafish and exhibits differential necessities in distinct types of germ granules.
title_full_unstemmed The piRNA protein Asz1 is essential for germ cell and gonad development in zebrafish and exhibits differential necessities in distinct types of germ granules.
title_short The piRNA protein Asz1 is essential for germ cell and gonad development in zebrafish and exhibits differential necessities in distinct types of germ granules.
title_sort pirna protein asz1 is essential for germ cell and gonad development in zebrafish and exhibits differential necessities in distinct types of germ granules
url https://doi.org/10.1371/journal.pgen.1010868
work_keys_str_mv AT adamahmad thepirnaproteinasz1isessentialforgermcellandgonaddevelopmentinzebrafishandexhibitsdifferentialnecessitiesindistincttypesofgermgranules
AT yoelbogoch thepirnaproteinasz1isessentialforgermcellandgonaddevelopmentinzebrafishandexhibitsdifferentialnecessitiesindistincttypesofgermgranules
AT galshvaizer thepirnaproteinasz1isessentialforgermcellandgonaddevelopmentinzebrafishandexhibitsdifferentialnecessitiesindistincttypesofgermgranules
AT nogaguler thepirnaproteinasz1isessentialforgermcellandgonaddevelopmentinzebrafishandexhibitsdifferentialnecessitiesindistincttypesofgermgranules
AT karinelevy thepirnaproteinasz1isessentialforgermcellandgonaddevelopmentinzebrafishandexhibitsdifferentialnecessitiesindistincttypesofgermgranules
AT yanivmelkouby thepirnaproteinasz1isessentialforgermcellandgonaddevelopmentinzebrafishandexhibitsdifferentialnecessitiesindistincttypesofgermgranules
AT adamahmad pirnaproteinasz1isessentialforgermcellandgonaddevelopmentinzebrafishandexhibitsdifferentialnecessitiesindistincttypesofgermgranules
AT yoelbogoch pirnaproteinasz1isessentialforgermcellandgonaddevelopmentinzebrafishandexhibitsdifferentialnecessitiesindistincttypesofgermgranules
AT galshvaizer pirnaproteinasz1isessentialforgermcellandgonaddevelopmentinzebrafishandexhibitsdifferentialnecessitiesindistincttypesofgermgranules
AT nogaguler pirnaproteinasz1isessentialforgermcellandgonaddevelopmentinzebrafishandexhibitsdifferentialnecessitiesindistincttypesofgermgranules
AT karinelevy pirnaproteinasz1isessentialforgermcellandgonaddevelopmentinzebrafishandexhibitsdifferentialnecessitiesindistincttypesofgermgranules
AT yanivmelkouby pirnaproteinasz1isessentialforgermcellandgonaddevelopmentinzebrafishandexhibitsdifferentialnecessitiesindistincttypesofgermgranules