Biased assembly of the nuclear pore complex is required for somatic and germline nuclear differentiation in Tetrahymena.
J Cell Sci
; 128(9): 1812-23, 2015 May 01.
Article
em En
| MEDLINE
| ID: mdl-25788697
ABSTRACT
Ciliates have two functionally distinct nuclei, a somatic macronucleus (MAC) and a germline micronucleus (MIC) that develop from daughter nuclei of the last postzygotic division (PZD) during the sexual process of conjugation. Understanding this nuclear dimorphism is a central issue in ciliate biology. We show, by live-cell imaging of Tetrahymena, that biased assembly of the nuclear pore complex (NPC) occurs immediately after the last PZD, which generates anterior-posterior polarized nuclei MAC-specific NPCs assemble in anterior presumptive MACs but not in posterior presumptive MICs. MAC-specific NPC assembly in the anterior nuclei occurs much earlier than transport of Twi1p, which is required for MAC genome rearrangement. Correlative light-electron microscopy shows that addition of new nuclear envelope (NE) precursors occurs through the formation of domains of redundant NE, where the outer double membrane contains the newly assembled NPCs. Nocodazole inhibition of the second PZD results in assembly of MAC-specific NPCs in the division-failed zygotic nuclei, leading to failure of MIC differentiation. Our findings demonstrate that NPC type switching has a crucial role in the establishment of nuclear differentiation in ciliates.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Tetrahymena
/
Poro Nuclear
/
Macronúcleo
/
Micronúcleo Germinativo
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
J Cell Sci
Ano de publicação:
2015
Tipo de documento:
Article
País de afiliação:
Japão