The sperm-interacting proteome in the bovine isthmus and ampulla during the periovulatory period

Abstract

Background Spermatozoa interact with oviduct secretions before fertilization in vivo but the molecular players of this dialog and underlying dynamics remain largely unknown. Our objectives were to identify an exhaustive list of sperm-interacting proteins (SIPs) in the bovine oviduct fluid and to evaluate the impact of the oviduct anatomical region (isthmus vs. ampulla) and time relative to ovulation (pre-ovulatory vs. post-ovulatory) on SIPs number and abundance. Methods Pools of oviduct fluid (OF) from the pre-ovulatory ampulla, pre-ovulatory isthmus, post-ovulatory ampulla, and post-ovulatory isthmus in the side of ovulation were collected from the slaughterhouse. Frozen-thawed bull sperm were incubated with OF or phosphate-buffered saline (control) for 60 min at 38.5 °C. After protein extraction and digestion, sperm and OF samples were analyzed by nanoLC-MS/MS and label-free protein quantification. Results A quantitative comparison between proteins identified in sperm and OF samples (2333 and 2471 proteins, respectively) allowed for the identification of 245 SIPs. The highest number (187) were found in the pre-ovulatory isthmus, i.e., time and place of the sperm reservoir. In total, 41 SIPs (17%) were differentially abundant between stages in a given region or between regions at a given stage and 76 SIPs (31%) were identified in only one region × stage condition. Functional analysis of SIPs predicted roles in cell response to stress, regulation of cell motility, fertilization, and early embryo development. Conclusion This study provides a comprehensive list of SIPs in the bovine oviduct and evidences dynamic spatio-temporal changes in sperm-oviduct interactions around ovulation time. Moreover, these data provide protein candidates to improve sperm conservation and in vitro fertilization media.

Oral exposure to bisphenol S is associated with alterations in the oviduct proteome of an ovine model, with aggravated effects in overfed females

“…The prediction of conventional (presence of a signal peptide) and unconventional secretory pathways of identified proteins was performed as previously described [ 6 ]. Briefly, FASTA sequences of all identified proteins were retrieved from Uniprot ID mapping online tool, and were used as inputs into the Outcyte online tool (version 1.0; http://www.outcyte.com/ ) [ 56 ] and SignalP in Eukarya organism (version 6.0; https://services.healthtech.dtu.dk/services/SignalP-6.0/ ) [ 57 ].…”

Sperm-fluid-cell interplays in the bovine oviduct: glycosaminoglycans modulate sperm binding to the isthmic reservoir

“…Based on our recent proteomic data which identified proteins interacting with bull sperm in the OF, including those previously identified as sperm receptors on oviduct epithelial cells 8 , our hypothesis was that the sperm rapidly interacted with soluble proteins in the OF, preventing further attachment at the surface of OES through a process of binding competition.…”

“…The OF is a complex biological fluid containing proteins, glycosaminoglycans, metabolites, hormones, and lipids that are highly regulated across the estrous cycle of cows 7 . Previous data from our lab identified 245 proteins in bovine OF that interacted with spermatozoa 8 including those previously proposed as sperm receptors in the isthmic reservoir, i.e., annexins A1, A2, A4, A5, and heat shock proteins 60 and A5, among others 4 , 9 , 10 . Proteins in the OF are then expected to compete with the same proteins located on the oviduct epithelium and decrease the binding of sperm to epithelial cells.…”