Project description:The zona pellucida plays a crucial role in the process of fertilization to early embryonic development, including cellular arrangement and communication between blastomeres. However, little is known regarding the role of the zona pellucida in pre- and post-implantation embryonic development associated with gene expression. We investigated the effects of the zona pellucida on the development and gene expression of pre- and post-implantation embryos. After the zona pellucida was removed at the 2-cell stage, compaction occurred earlier. In addition, the expression of differentiation-related genes in the inner cell mass (ICM) (Oct4, Sox21) and trophectoderm (TE) (Cdx2, Eomes, and Tfap2c) was significantly altered in both zona free (ZF) morula and blastocyst compared to zona intact embryos. After embryo transfer, the implantation rate and number of live fetuses were lower in ZF embryos than in control embryos, whereas the fetal weight at birth was not different. However, placental weight was significantly increased in ZF embryos. RNA-seq analysis of the placenta showed that a total of 473 differentially expressed genes that significantly influenced the biological process. The present study suggests that zona pellucida removal at the 2-cell stage not only disturbs the expression pattern of ICM/TE-related genes, but affects the post-implantation development of mouse embryos. Overall, this study provides a deeper insight into the role of the zona pellucida during early mouse embryonic development and the viability of post-implantation development. It also provides a valuable basis for future research related to the production of ZF embryos in mammals and the developmental properties of blastomeres.
Project description:The human chromosomal region 17q12-q21 is associated with childhood asthma. It harbors 5 protein-coding genes, of which ORMDL sphingolipid biosynthesis regulator 3 (ORMDL3) and gasdermin B (GSDMB) are the top causal gene candidates. Emerging evidence suggests that the promoter region of another gene, the zona pellucida binding protein 2 (ZPBP2), located more than 50kb proximal to ORMDL3 may be critical for its transcriptional regulation influencing susceptibility to asthma. To test this hypothesis, we examined the lung phenotypes, liver transcriptomes and lipid metabolism of Zpbp2 knock-out (KO) mice. We found that in comparison to wild type (WT) mice, Zpbp2 KO mice sensitized with allergen ovalbumin (OVA) had reduced bronchial reactivity. The Zpbp2 KO mice also had altered lipid metabolism with a 3-fold decrease in the levels of docosahexaenoic acid (DHA), increased body weight and changes in the expression of the adipocytokine signaling pathway gene peroxisome proliferator activated receptor alpha (Pparα). The Zpbp2 deletion was also associated with increased DNA methylation at the Zpbp2 promoter/enhancer region, reminiscent of the methylation of the orthologous region in humans, and reduced expression of Ormdl3 in liver. The sum of our results implies that the Zpbp2 gene is involved in the regulation of airway hypersensitivity and lipid metabolism, either directly or through a cis-regulatory effect on Ormdl3.
Project description:All mammalian eggs are surrounded by a relatively thick extracellular coat, the zona pellucida, that plays vital roles during oogenesis, fertilization, and preimplantation development. The mouse zona pellucida consists of three glycoproteins that are synthesized solely by growing oocytes and assemble into long fibrils that constitute a matrix. Zona pellucida glycoproteins are responsible for species-restricted binding of sperm to unfertilized eggs, inducing sperm to undergo acrosomal exocytosis, and preventing sperm from binding to fertilized eggs. Many features of mammalian and non-mammalian egg coat polypeptides have been conserved during several hundred million years of evolution.