Protamine Ratio as Predictor of the Fertility Potential of Sperm by Couple Undergoing ICSI

Abstract

Objectives: The present study aimed to measure the protamines P1 and P2 concentrations, standard sperm parameters, and also DNA fragmentation and condensation. In addition, the correlations between the above-mentioned variables and the P1/P2 ratio were explored in order to find out whether the ratio could be used as a biomarker for semen quality. Materials and Methods: A total of 272 semen samples were divided into 3 P1/P2 ratio groups: G1 as low (<0.8), G2 as normal (0.8-1.2), and G3 as high (>1.2) ratios. DNA fragmentation and condensation were evaluated by TUNEL and CMA3 (chromomycinA 3 ) assays and protamine levels (P1 and P2) were measured using acid urea polyacrylamide gel (AU-PAGE) electrophoresis and western blot (WB). Results: In G1, CMA3 positive and DNA fragmentation index (DFI) were negatively correlated (r = -0.371, P = 0.001). In addition, P1/P2 ratio had a positive correlation with DFI (r = 0.652, P = 0.001);however it had a negative association with CMA3 (r = -0.623, P = 0.001). Moreover, G2 demonstrated positive correlations between sperm concentration and P1(r = 0.257, P = 0.011) and P2 (r = 0.277, P = 0.006), progressive motility, and P1 (r = 0.352, P = 0.001). The P2 was positively correlated with progressive motility (r = 0.380, P < 0.01). Besides, a positive relationship was found between P1/P2 ratio and CMA3 (r = 0.333, P = 0.001). In contrast, normal morphology showed a negative association (P < 0.05) with P1 (r = -0.206) and P2 (r = -0.208).Meanwhile, there was a negative correlation between P1 and DFI (r = -0.207, P = 0.041) as well. Finally, in G3, negative correlations were also observed between P1 and normal morphology (r = -.283, P = .027) and also P1/P2 ratio and P2 (r = -0.372, P = 0.003) while DFI showed a positive correlation with CMA3 (r = 0.299, P = 0.019).