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Involvement of chromatin structure in the regulation of mouse zygotic gene activation
Author(s) -
CHO Tasuku,
SAKAI Senkiti,
NAGATA Masao,
AOKI Fugaku
Publication year - 2002
Publication title -
animal science journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.606
H-Index - 38
eISSN - 1740-0929
pISSN - 1344-3941
DOI - 10.1046/j.1344-3941.2002.00017.x
Subject(s) - chromatin , aphidicolin , biology , deoxyribonuclease i , zygote , microbiology and biotechnology , embryo , maternal to zygotic transition , cell , transcription (linguistics) , gene , dnase i hypersensitive site , cell cycle , genetics , embryogenesis , linguistics , philosophy , base sequence
We investigated the contribution of the global changes in chromatin structure to the mechanism regulating zygotic gene activation in mouse embryos by in vitro transcription assay and in situ DNase I sensitivity assay. Changes in the DNase I sensitivity and transcriptional activity were similar from the late 1‐cell to the late 2‐cell stage, but were not in the early 1‐cell stage. The DNase I sensitivity decreased at the late 1‐cell stage when compared with the sensitivity at the early 1‐cell stage. It increased at the early 2‐cell stage and then decreased at the late 2‐cell stage. Similarly, the transcriptional activity increased at the early 2‐cell stage when compared with the activity at the late 1‐cell stage, and then decreased at the late 2‐cell stage. The DNase I sensitivity was not decreased in embryos which were treated with aphidicolin, where the first round of DNA replication was inhibited. A similar result was observed in embryos when the second DNA replication was inhibited. These results suggested that the chromatin structure is one of the important factors regulating gene expression from the late 1‐cell stage and that DNA replication is an event responsible for the establishment of the repressive state in the chromatin structure. The inhibition of protein synthesis did not affect the DNase I sensitivity in the 1‐cell embryos, while it is known that protein synthesis is indispensable for gene activation. This result suggests that the protein synthesized after fertilization, but not the chromatin structure, is responsible for the initiation of the gene activation.