Genetic loss of importin α4 causes abnormal sperm morphology and impacts on male fertility in mouse.
FASEB J
; 34(12): 16224-16242, 2020 12.
Article
em En
| MEDLINE
| ID: mdl-33058343
ABSTRACT
Importin α proteins play a central role in the transport of cargo from the cytoplasm to the nucleus. In this study, we observed that male knock-out mice for importin α4, which is encoded by the Kpna4 gene (Kpna4-/- ), were subfertile and yielded smaller litter sizes than those of wild-type (WT) males. In contrast, mice lacking the closely related importin α3 (Kpna3-/- ) were fertile. In vitro fertilization and sperm motility assays demonstrated that sperm from Kpna4-/- mice had significantly reduced quality and motility. In addition, acrosome reaction was also impaired in Kpna4-/- mice. Transmission electron microscopy revealed striking defects, including abnormal head morphology and multiple axoneme structures in the flagella of Kpna4-/- mice. A five-fold increase in the frequency of abnormalities in Kpna4-/- mice compared to WT mice indicates the functional importance of importin α4 in normal sperm development. Moreover, Nesprin-2, which is a component of the linker of nucleus and cytoskeleton complex, was expressed at lower levels in sperm from Kpna4-/- mice and was localized with abnormal axonemes, suggesting incorrect formation of the nuclear membrane-cytoskeleton structure during spermiogenesis. Proteomics analysis of Kpna4-/- testis showed significantly altered expression of proteins related to sperm formation, which provided evidence that genetic loss of importin α4 perturbed chromatin status. Collectively, these findings indicate that importin α4 is critical for establishing normal sperm morphology in mice, providing new insights into male germ cell development by highlighting the requirement of importin α4 for normal fertility.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Motilidade dos Espermatozoides
/
Espermatozoides
/
Carioferinas
/
Alfa Carioferinas
/
Fertilidade
/
Infertilidade Masculina
Tipo de estudo:
Etiology_studies
Limite:
Animals
Idioma:
En
Revista:
FASEB J
Assunto da revista:
BIOLOGIA
/
FISIOLOGIA
Ano de publicação:
2020
Tipo de documento:
Article
País de afiliação:
Japão