Bull subfertility is associated with low levels of a sperm membrane antigen

Selected Proteins of “Prostasome-Like Particles” from Epididymal Cauda Fluid Are Transferred to Epididymal Caput Spermatozoa in Bull1

“…The pattern of proteins associated with PLP is probably much more complex considering that some of them are not exposed to the PLP surface and thus are not accessible to biotinylation. This is the case for P25b, a protein previously shown to be PLP associated and transferred to the sperm surface during epididymal transit [13,19]. Therefore, the pattern of proteins associated with epididymal PLP is probably as complex as that for prostasomes, with which as many as 80 different proteins can be associated [22].…”

Cryopreservation Alters the Levels of the Bull Sperm Surface Protein P25b

“…The difference in P25b level between the 8 bulls used in this study can be as high as a threefold difference (data not shown). Using frozen-thawed spermatozoa, we have previously shown that low levels of P25b are observed only on spermatozoa from poor-fertility bulls (low NRR; Parent et al, 1999). One hypothesis would be that this interindividual variability in P25b levels associated with thawed spermatozoa is due to a variation in sperm sensitivity to P25b cryoelution from one bull to another.…”

Immunolocalization of Fertilin β, IZUMO1, and P34H in Ram Spermatozoa

“…This event was thought to occur according to the location of IZUMO1, which is thought to be an important protein for fusion. 46 It has been reported that the ortholog of P34H in human spermatozoa has been detected in bulls 47 and monkeys. 48,49 Sullivan and Mieusset 50 revealed that once the sperm passes through the epididymis during their maturation, the P34H protein migrates to the posterior region of the spermatozoa head on the plasma membrane, and it has been stated to be one of the necessary preconditions for fertilization in humans.…”