Alterations of Histone H۳ Trimethylated at Positions K۴ and K۲۷ in Zygote Genome Activation Stage of Mouse

Background: Histone modifications have serious roles in regulatingthe expression of developmental genes during embryodevelopment in mammals. Methylation of histones is one ofthe most important epigenetic modifications and has a criticalrole in both transcriptional repression and activation duringembryonic development. Histone H۳ lysine ۴ trimethylation(H۳K۴me۳) is an epigenetic marker associated with activetranscription, and it has a close relationship with histone acetylationand deacetylation. Also, histone H۳ lysine ۲۷ trimethylation(H۳K۲۷me۳) is involved in silencing of gene expression.On the other, first main developmental event that occursfollowing fertilization is Zygotic gene activation. This episodeis responsible for dramatic reprogramming of gene expressionthat occurs during the ۲-cell stage of the mouse. Therefore, the aim of this study was to investigate the distribution patternedof H۳K۴me۳ and H۳K۲۷me۳ in ۲-cell stage of mouse embryousing immunofluorescence staining.Materials and Methods: Two cell embryos fixed ۲۴ hours afterinsemination and stained with specific antibody for modificationin H۳K۲۷me۳ and H۳K۴me۳. The fluorescence imagesinvestigated and relative intensity calculated using the Image-J.Data analyzed by two independent sample t-tests. Differenceswere considered as significant at P<۰.۰۵.Results: The results indicated H۳K۴me۳ and H۳K۲۷me۳ signalswere ۴۰.۲۹ ± ۶.۰۳, ۲۵.۲۸ ± ۲.۰۲ respectively. A sharp increasein the intensity of H۳K۴me۳ observed that was significantlyhigher than H۳K۲۷me۳ in ۲ cells.Conclusion: The changes in gene expression occur in ZGA sothe levels of H۳K۴me۳, which is involved in gene regulation;show dramatically increased likely has amplified gene expressionin the major wave of zygotic genome activation in the twocellmouse embryo.

کلیدواژه ها:

H۳K۴me۳ ، Mouse ، H۳K۲۷me۳ ، Zygote Genome Activation