Identification of Bovine Sperm Surface Proteins Involved in Carbohydrate-mediated Fertilization Interactions

Abstract

Glycan-protein interactions play a key role in mammalian fertilization, but data on the composition and identities of protein complexes involved in fertilization events are scarce, with the added complication that the glycans in such interactions tend to differ among species. In this study we have used a bovine model to detect, characterize and identify sperm lectins relevant in fertilization. Given the complexity of the sperm-toward-egg journey, two important aspects of the process, both primarily mediated by protein-sugar interactions, have been addressed: (1) formation of the sperm reservoir in the oviductal epithelium, and (2) gamete recognition (oocytesperm interaction). Using whole sperm cells and a novel affinity capture method, several groups of proteins with different glycan specificities, including 58 hitherto unreported as lectins, have been identified in sperm surface, underscoring both the efficacy of our selective approach and the complex composition and function of sperm. Based on these results and previous data, we suggest that sperm surface proteins play significant roles in fertilization events such as membrane remodeling, transport, protection and function, thus supporting the hypothesis that rather than a simple lock-and-key model, mammalian fertilization relies on a complex interactome involving multiple ligands/receptors and recognition/binding events. Molecular & Cellular

Comparative transcriptome analysis of three gonadal development stages reveals potential genes involved in gametogenesis of the fluted giant clam (Tridacna squamosa)

“…In addition, the present study also found significantly higher expression of SP17 and Sperm Specific Protein in male than in resting and hermaphroditic clams, and the expression difference might be associated with spermatogenesis. In bovine sperm, SP17 had been found to be essential for spermatogenesis and played significant roles in fertilization events, such as membrane remodeling, transport, protection and function [ 70 ]. However, the role of SP17 in T. squamosa spermatogenesis remains further investigation.…”

Bovine sperm-oviduct interactions are characterized by specific sperm behaviour, ultrastructure and tubal reactions which are impacted by sex sorting

“…Each of these proteins alone can mediate the binding of bovine spermatozoa to the tubal epithelium 19,30,66 . To date, 58 sperm proteins located on the bovine sperm head have been identified 67 . Thus, damage to the head of the spermatozoa might result in altered function of these lectins, resulting in compromised initiation of the calcium signalling cascades which are induced after sperm binding 68 .…”

Gelatin Binding Proteins in Reproductive Physiology

“…The ampulla-isthmus has been identified as a reservoir for sperm in many mammals such as cattle, horse, pigs, mice, hamsters, guinea pigs and camelids [5,[36][37][38]. The occurrence of a sperm reservoir performs significant for three main reasons; (1) It reduces polyspermy by permitting fewer spermatozoa to reach the site of fertilization in the ampulla, (2) It allows for the selection of highly Fig.…”