Remodeling of Histone H3 Lysine 27 Trimethylation in Early Mouse Zygote

Remodeling of Chromatin is a multi-stage process in the newly fertilized oocyte that changeover between gametic chromatin and embryonic chromatin and will shortly become transcriptionally competent. Trimethylation of histone H3 at lysine 27 (H3K27me3) is a suppressive epigenetic mark that appears during pre-implantation development changes in mice. In general, histone methylation is associated with gene silencing, with the exception of h3k4, which is linked with increased gene transcription. The aim of this study was assessing the levels of H3K27me3 in early mouse zygote using immunofluorescence staining. Zygotes were fixed at 6 hours after insemination and stained with an antibody specific for modification in h3k27me3. Results showed that asymmetric staining of H3K27me3 in the maternal and paternal PNs of mice. H3K27me3 staining was positive and negative in maternal and paternal PNs, respectively. Detailed analysis of the early zygote stage in mice shown that immediately after fertilization, at PN0, H3K27me3 was only limited on the maternal PN, and this asymmetry was continued until the initial PN4 stage when the male PN becomes slowly positive for H3K27me3.In conclusion, early asymmetry H3K27me3 staining may be due to the paternal protamines was being exchanged via maternally-stored histones, however the maternal chromatin stains intensively for H3K27me3.

کلیدواژه ها:

Zygote ، H3k27me3 ، Mouse ، Chromatin ، Epigenetic