Reduction of cortical pulling at mitotic entry facilitates aster centration.
J Cell Sci
; 137(7)2024 Apr 01.
Article
em En
| MEDLINE
| ID: mdl-38469748
ABSTRACT
Equal cell division relies upon astral microtubule-based centering mechanisms, yet how the interplay between mitotic entry, cortical force generation and long astral microtubules leads to symmetric cell division is not resolved. We report that a cortically located sperm aster displaying long astral microtubules that penetrate the whole zygote does not undergo centration until mitotic entry. At mitotic entry, we find that microtubule-based cortical pulling is lost. Quantitative measurements of cortical pulling and cytoplasmic pulling together with physical simulations suggested that a wavelike loss of cortical pulling at mitotic entry leads to aster centration based on cytoplasmic pulling. Cortical actin is lost from the cortex at mitotic entry coincident with a fall in cortical tension from â¼300pN/µm to â¼100pN/µm. Following the loss of cortical force generators at mitotic entry, long microtubule-based cytoplasmic pulling is sufficient to displace the aster towards the cell center. These data reveal how mitotic aster centration is coordinated with mitotic entry in chordate zygotes.
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Base de dados:
MEDLINE
Assunto principal:
Sêmen
/
Fuso Acromático
Limite:
Humans
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Male
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article