Is there a relationship between infertility and fertilin ß protein distribution?

INTRODUCTION: Fertilin ß is a sperm surface protein that can mediate sperm-egg membrane interaction. This study was conducted to determine whether the expression of fertilin ß after intrauterine insemination (IUI) in donors with normal parameters after standard semen analysis is related to low success rate or failure of fertilization. METHODS: We examined the sperm of 30 male donors who have normal as controls, oligozoospermia, and unexplained infertility as the clinically indication for IUI. Fertilin ß has been labeled with the ADAM2 antibody by indirect immunofluorescence (IF) assay. To evaluate the reproducibility of the test, we selected four sperm samples scale of 0 to +++ according to the distribution of fluorescence label. RESULTS: The results were highly correlated with the corrected total cell fluorescence (CTCF) (Rp=0.9972, P<0.05). We suggest that the relationship between infertility and fertilin ß may be due to the distribution of this protein on the sperm surface. Male partners of couples with unexplained infertility showed a low distribution of fertilin ß by a decrease of the fluorescence signal in the IF labeling (scale of +++ by 7.4±10.32%, P<0.0001, ±SD). DISCUSSION: Abnormal fertilin ß function may be a potential mechanism that could lead to fertilization failure.