Insights into epigenetic patterns in mammalian early embryos

Mammalian fertilization begins with the fusion of two specialized gametes, followed by major epigenetic remodeling leading to the formation of a totipotent embryo. During the development of the pre-implantation embryo, precise reprogramming progress is a prerequisite for avoiding developmental defects or embryonic lethality, but the underlying molecular mechanisms remain elusive. For the past few years, unprecedented breakthroughs have been made in mapping the regulatory network of dynamic epigenomes during mammalian early embryo development, taking advantage of multiple advances and innovations in low-input genome-wide chromatin analysis technologies. The aim of this review is to highlight the most recent progress in understanding the mechanisms of epigenetic remodeling during early embryogenesis in mammals, including DNA methylation, histone modifications, chromatin accessibility and 3D chromatin organization.

The role of ripply1 in zebrafish dorsal-ventral development / 中国实验动物学报

Objective To explore the role of ripply1 in zebrafish dorsal-ventral development .Methods Using ze-brafish whole-mount in situ hybridization to examine the ripply1 expression pattern in early embryo development .To analyse the expression pattern changes of dorsal-ventral marker genes at shield stage and the morphological changes at 24 hpf (hours post-fertilization) after overexpression of ripply1 by injecting synthetic mRNA at 1-cell stage.Using Tol2 transposon technology to obtain a ripply1 promoter driven GFP transgenic fish and to identify promoter region that recapitulates endoge -nous ripply1 expression pattern .Results The in situ hybridization results revealed that ripply1 specifically expresses in the future dorsal region at shield stage .Overexpression of ripply1 caused an enhanced expression of dorsal marker genes and a reduction of ventral marker genes .Embryos overexpressing ripply1 also showed severely dorsalized phenotype , with enlarged head, reduced ventral yolk extension , and shortened posterior trunk and tail regions , and the formation of a secondary trunk axis.Transgenic fish revealed the maternal expression of ripply1 and suggested that a 1.2 kb promoter-driven GFP is able to recapitulate the endogenous gene expression pattern .Conclusion ripply1 may participate in the early development of dor-sal-ventral axis in zebrafish embryo .

THE ROLES OF SYMPATHETIC NERVE ON EMBRYO IMPLANTATION AND LOCAL IMMUNITY IN UTERUS OF MICE / 解剖学报

Objective To explore the effect mechanism of sympathetic nerve on early developing embryo of mice. Methods The model of sympathectomy mouse was established by 6-OHDA injected intraperitoneally.The early developing mice embryo and lymphocytes in uterus were observed using histology,immunohistochemistry and ELISA methods. Results In sympathectomy mouse,the number of embryo implantation was decrease to 64.4%,endometrial lamina propria and vascellum were shortfall.The numbers of CD4~+T cell and CD8~+T cell in sympathectomy mice were larger than ones in control groups,especially,the number of CD8~+T cells at E3 and E5 differed highly(P