Abstract: PD08-01
Sources of Funding: none

Introduction

Despite to many animal models, the human sperm reservoir has not been described or characterized yet. The formation of the sperm reservoir is pivotal for maintaining sperm fertilizing capacity and for successful fertilization and pregnancy. In this study, the binding mechanism of human sperm to oviduct epithelium was investigated regarding glycoproteins on the surface of sperm plasma membrane and the surface of the oviduct epithelium. It was recently shown that several parts of sperm glycocalix might play an important role in the interaction with the female reproductive tract (Tecle and Gagneux, 2015) and potentially in formation of a sperm reservoir in the oviduct

Methods

Oviducts from 16 women that undergo hysterectomy treatment and 100 semen samples from healthy and infertile patients were analysed. For sperm-oviduct interaction, oviducts with naturally occurring spermatozoa and manually inseminated sperm were sampled. For this reason samples were prepared and analysed by Scanning Electron Microscopy (SEM). Fixed tissue sections from oviducts (ampulla region) were stained with Hoechst3342 and Fluorescein isothiocyanate (FITC) conjugated WGA, ConA, MPA and MAA lectins that recognize specific sugar residues on surface of tissues. Fresh sperm specimen were washed, fixed and stained with a FITC-conjugate of sialic acid, fucose, mannose and galactose. Fluorescence was analysed with a confocal scanning microscope.

Results

With SEM experiments showed that sperm can be found bound to the oviduct after three days of sexual intercourse; secretory cells play an important role in sperm binding. We found that N-acetylglucosaminyl residues are only situated on top of secretory cells in the oviduct; galactose and sialic acids residues were rare. Mannose can be found in cytoplasm of cells. It can be seen that molecules on plasma membrane bind different sugar motifs and that these molecules are mainly located in head region.

Conclusions

Our experiments give indication that glycoconjugates on surface of oviduct epithelium and sperm plasma membrane might take part in this important interaction. With this knowledge investigation on idiopathic infertility for men regarding surface binding molecules might be possible in future.

Funding

none