Background
Sperms during epididymal transit acquire microRNAs(miRNAs), which are crucial for embryonic development. However, whether miRNAs transmitted from an obstructive epididymal environment affect embryonic development remains unknown. The purpose of the present study was to investigate the effects of an obstructive epididymal environment on embryonic development.
Method
The control group (CON) and the obstructive epididymal environment group(OEE) were treated with sham operation and vasectomy, respectively. The effects of an obstructive epididymal environment on testis, epididymis, sperm, and embryonic development were analyzed via hematoxylin and eosin staining (HE staining), sperm quality test, epididymosomes fusion, intracytoplasmic sperm injection (ICSI) and embryo transfer. Moreover, sRNA sequence, RT-qPCR, and DNA methylation were conducted to investigate the regulation of sperm miRNAs by an obstructive epididymal environment. miRNAs microinjection and embryo transfer were used to explore the impacts of sperm miRNAs on embryonic development.
Results
The long obstructive interval impaired the morphology of the testis and epididymis. In comparison to the CON group, the OEE group had lower sperm quality and developmental potential. Sperm miRNAs profiles were also altered in the OEE group, particularly the developmental miR-17-92 cluster and Sfmbt2 miRNA clusters; the expression of these two miRNA clusters was regulated via epididymal DNA methylation; however, the disruption of neither the miR-17-92 cluster nor the Sfmbt2 miRNA clusters into normal zygotes did not impair embryonic development.
Conclusion
The obstructive epididymal environment influences embryonic development and the abundance of the sperm miR-17-92 cluster and the sfmbt2 miRNA cluster, but these miRNA clusters are not the cause of abnormal embryo development. It implies that epididymis is important in early embryonic development and may play a potential role in sperm epigenome.