Spermatocytes have the capacity to segregate chromosomes despite centriole duplication failure.
EMBO Rep
; 25(8): 3373-3405, 2024 Aug.
Article
em En
| MEDLINE
| ID: mdl-38943004
ABSTRACT
Centrosomes are the canonical microtubule organizing centers (MTOCs) of most mammalian cells, including spermatocytes. Centrosomes comprise a centriole pair within a structurally ordered and dynamic pericentriolar matrix (PCM). Unlike in mitosis, where centrioles duplicate once per cycle, centrioles undergo two rounds of duplication during spermatogenesis. The first duplication is during early meiotic prophase I, and the second is during interkinesis. Using mouse mutants and chemical inhibition, we have blocked centriole duplication during spermatogenesis and determined that non-centrosomal MTOCs (ncMTOCs) can mediate chromosome segregation. This mechanism is different from the acentriolar MTOCs that form bipolar spindles in oocytes, which require PCM components, including gamma-tubulin and CEP192. From an in-depth analysis, we identified six microtubule-associated proteins, TPX2, KIF11, NuMA, and CAMSAP1-3, that localized to the non-centrosomal MTOC. These factors contribute to a mechanism that ensures bipolar MTOC formation and chromosome segregation during spermatogenesis when centriole duplication fails. However, despite the successful completion of meiosis and round spermatid formation, centriole inheritance and PLK4 function are required for normal spermiogenesis and flagella assembly, which are critical to ensure fertility.
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Base de dados:
MEDLINE
Assunto principal:
Espermatócitos
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Espermatogênese
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Centríolos
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Segregação de Cromossomos
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Centro Organizador dos Microtúbulos
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Proteínas Associadas aos Microtúbulos
Limite:
Animals
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article