Premium
Immunofluorescent localization of actin in relation to transcription sites in mouse pronuclei
Author(s) -
Nguyen Eric,
Besombes Didier,
Debey Pascale
Publication year - 1998
Publication title -
molecular reproduction and development
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.745
H-Index - 105
eISSN - 1098-2795
pISSN - 1040-452X
DOI - 10.1002/(sici)1098-2795(199807)50:3<263::aid-mrd2>3.0.co;2-h
Subject(s) - biology , nucleoplasm , microbiology and biotechnology , cell nucleus , actin , transcription (linguistics) , colocalization , pronucleus , embryo , cytochalasin d , cell , zygote , nucleus , nucleolus , genetics , cytoskeleton , embryogenesis , linguistics , philosophy
Previous biochemical and morphological studies have shown the presence of actin in the nucleus of different cell types where its role remains unclear. In this work, through fluorescence microscopy we studied the localization of actin in the nuclei of early mouse embryos with particular attention to its possible involvement in the onset of transcription occurring at the late one‐cell stage. Fluorescent labelling of embryo sections showed that nuclear actin is abundant, in a non‐filamentous state, in the whole nucleoplasm excluding the nucleolar precursor bodies. Immunofluorescence on permeabilized embryos revealed that insoluble nuclear actin accumulates in a few large aggregates in transcriptionally inert early one‐cell embryos and progressively redistributes into many small aggregates in transcriptionally active late one‐cell embryos. Interestingly, these actin aggregates clearly colocalize with transcription sites. Treatment of late one‐cell embryos with cytochalasin D induces the formation of actin bundles network in the nucleoplasm but has no apparent effect on the transcriptional activity. In addition, the inhibition of transcription by α‐amanitin does not modify the nuclear actin distribution. Hence, there does not appear to be a direct causal relationship between transcriptional activity and nuclear actin organization at the one‐cell stage although nuclear actin aggregates appear associated with transcription sites. Mol. Reprod. Dev. 50:263–272, 1998. © 1998 Wiley‐Liss, Inc.