Medaka Terb1 Mutant Displays Defects of Synaptonemal Complex Formation and Sexual Difference in Gametogenesis.
Zoolog Sci
; 41(3): 314-322, 2024 Jun.
Article
in En
| MEDLINE
| ID: mdl-38809870
ABSTRACT
Formation of the synaptonemal complex (SC) is a prerequisite for proper recombination and chromosomal segregation during meiotic prophase I. One mechanism that ensures SC formation is chromosomal movement, which is driven by the force derived from cytoskeletal motors. Here, we report the phenotype of medaka mutants lacking the telomere repeat binding bouquet formation protein 1 (TERB1), which, in combination with the SUN/KASH protein, mediates chromosomal movement by connecting telomeres and cytoskeletal motors. Mutations in the terb1 gene exhibit defects in SC formation in medaka. Although SC formation was initiated, as seen by the punctate lateral elements and fragmented transverse filaments, it was not completed in the terb1 mutant meiocytes. The mutant phenotype further revealed that the introduction of double strand breaks was independent of synapsis completion. In association with these phenotypes, meiocytes in both the ovaries and testes exhibited an aberrant arrangement of homologous chromosomes. Interestingly, although oogenesis halted at the zygotene-like stage in terb1 mutant, testes continued to produce sperm-like cells with aberrant DNA content. This indicates that the mechanism of meiotic checkpoint is sexually different in medaka, similar to the mammalian checkpoint in which oogenesis proceeds while spermatogenesis is arrested. Moreover, our results suggest that spermatogenesis is mechanistically dissociable from meiosis.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Oryzias
/
Synaptonemal Complex
/
Gametogenesis
/
Mutation
Limits:
Animals
Language:
En
Journal:
Zoolog Sci
/
Zoolog. sci
/
Zoological science
Journal subject:
BIOLOGIA
Year:
2024
Document type:
Article
Affiliation country:
Japan
Country of publication:
Japan