Reproduction Abstracts

Introduction: G9A-like protein (GLP) plays an important role in early mouse embryonic development as GLP-deficient embryos display severe growth retardation and defects, leading to lethality around embryonic day 9.5. In this study, we investigated the early role of GLP in controlling cell fate decisions by employing siRNA, which depleted both maternal and embryonic GLP mRNA during the mouse pre-implantation embryo. Our study demonstrates that GLP deficiency in the early mouse embryo led to long-term adverse effects on embryonic growth and development, including increased cell apoptosis. Furthermore, immunofluorescence staining revealed alterations in epigenetic modification due to GLP deficiency.

Materials and methods: IVF, mouse embryos, GLP siRNA, microinjection, immuofluoresence staining, qRT-PCR, western blotting, and TUNEL assay.

Results: In this study, we investigate the effect of microinjecting GLP-specific siRNA into mouse zygotes on in vitro embryonic development. Our results showed that GLP knockdown induced abnormal embryonic development and reduced blastocyst formation. Expression of the pluripotent markers Oct4, Sox2, and Nanog were also decreased significantly in GLP-deficient embryos. However, the apoptotic index and the expression of two pro-apoptotic genes, namely Caspase 3 and Caspase 9, were increased in GLP-deficient embryos. Moreover, the methylation levels of H3K27me2 and H3K9me2 were decreased in GLP knockdown embryos. In conclusion, these results suggest that GLP deficiency leads to abnormal blastocyst development and apoptosis due to changes in histone modification that may affect genes expression.