Parental noncoding RNA expression dynamics across sperm, oocyte, and zygote

Fertilization ensures the flow of information from the parent to the progeny via fusion of male and female gametes orchestrated by a cascade of events guided by parental noncoding RNA (ncRNA) molecules. These parental ncRNAs play an essential role toward rewiring the germ cell profile to make them compatible for successful fertilization, thereby resulting in the formation of the zygote. They further modulate the zygotic profile to support the postfertilization events. In this work, an in-depth meta-analysis of small and long RNA-seq data corresponding to sperm, oocyte, and one-cell stage zygote of Mus musculus has been performed, followed by subsequent wet bench experiments. Our findings provide a comprehensive long noncoding RNA (lncRNA) and microRNA (miRNA) profile contributed by the parental gametes. Further, a set of novel lncRNAs have been identified, which have a potential role toward modulating sperm and oocyte fertility in the pre-fertilization stage. Moreover, a fine-tuned miRNA expression dynamics has been observed between the germ cells and the zygote to increase the competency of the germ cells for fertilization in the pre-fertilization stage. Its subsequent effects have been observed on early embryonic development in the postfertilization stage.