Estimated Diversity Of Mrnas In Each Murine Spermatozoa And Their Potential Function During Early Zygotic Development

To study mRNA profile of murine spermatozoa and their potentialfunction during zygotic development, the total RNAs in murinespermatozoa were sequenced via RNA-Sequencing and confirmed byReal-Time PCR.Then we established mathematical model to s determinethe species of RNA and analyzed through bioinformatics techniques.Thedelivery and translation of sperm-borne mRNA in fertilized oocyte weredetected using RT-PCR (Reverse Transcription-Polymerase ChainReaction), Western blotting, and immunofluorescence.A total of35,288,825reads matching33,039transcripts, including27,310coding transcripts, were obtained. Based on our model, wehypothesized that the transcripts with RPKM (Reads Per Kilobase of exonmodel per Million mapped reads) higher than6may exist in each sperm cellas consistently retained transcripts. There were4,885consistent transcriptsin each sperm.If the baseline RPKM increased, the remained codingtranscripts were more likely related to reproduction and development. Itcould be speculated that the transcripts in sperm are selectively reserved.The sperm-borne transcripts Wnt4and Foxg1were delivered intofertilized oocytes upon fertilization. Furthermore, Wnt4was translated intoprotein in zygotes, whereas Foxg1was not translated but consistentlyretained in zygotes.In conclusion, approximately4,885mRNAs were present in eachmurine spermatozoon, and the spermatozoal mRNAs related toreproduction and development were more likely retained. The sperm-borne mRNAs Wnt4was delivered into the fertilized oocyte and translated, as anevidence of paternal effect on embryonic development.