Analysis of gene expression and chromatin structure during zygotic gene activation (ZGA) in round spermatid injection derived embryos. Mus musculus

Round spermatid (RS) is the immature male germ cells. RS has a haploid genome but not flagellum so that they can not fertilize the egg in natural. Some of the men can produce RS but no spermatozoa. If RS was artificially injected into the egg, the resultant embryos could develop to the full-term. However, the success rate is very lower compared to matured spermatozoa. Our goal is to reveal the cause of the lower offspring rate of ROSI (round spermatid injection)-derived embryos and to identify the solution. Since round spermatid has histone-based chromatin structure, we assumed that there are abnormalities in epigenome in ROSI derived embryos. To assess this, ATAC-seq and RNA-seq analysis were performed.