Separation of bovine spermatozoa proteins using 2D-PAGE revealed the relationship between tektin-4 expression patterns and spermatozoa motility

• Published in: Theriogenology Vol. 77; no. 9; pp. 1816 - 1821
• Main Authors: Thepparat, T, Katawatin, S, Vongpralub, T, Duangjinda, M, Thammasirirak, S, Utha, A
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.06.2012
• Subjects: 2D-PAGE; Animals; Bovine spermatozoa proteins; Brahman; bulls; Cattle - physiology; computer software; correlation; cutting; Cytoskeletal Proteins - genetics; Cytoskeletal Proteins - metabolism; Electrophoresis, Gel, Two-Dimensional - veterinary; gels; Gene Expression Regulation - physiology; Male; protein content; proteins; Proteins - genetics; Proteins - metabolism; semen; Semen Analysis - veterinary; Semen quality; sperm motility; Sperm Motility - physiology; spermatozoa; Spermatozoa - metabolism; Transcriptome; Bovine spermatozoa proteins; Semen quality; 2D-PAGE
• ISSN: 0093-691X; 1879-3231
• DOI: 10.1016/j.theriogenology.2011.12.027

Poor semen quality has long been associated with bull infertility. However, the molecular basis in spermatozoa cells underlying the mechanisms of bull infertility remain unknown. The purpose of this study was to determine whether there is any protein in bovine spermatozoa related to semen quality. Semen samples from 18 Brahman bulls, 3 to 10 yrs of age, were assessed for semen quality in terms of spermatozoa motility and spermatozoa morphology. Spermatozoa extracts were separated using 2D-PAGE followed by staining with Coomassie blue. At least one duplicate gel was performed for each sample. Each gel was scanned with an ImageScanner System and analyzed for spots by ImageMaster 2D platinum software. The related protein spot(s) with semen quality was cut from the gel and identified by LC MS/MS. The results showed that at least 600 protein spots were detected in the spermatozoa extracts of the Brahman bulls. Of all these spots, there were 3 of 56 kDa at pI 6.4, 6.6 and 6.8 (Z₁, Z₂ and Z₃, respectively) that clearly showed different expression pattern among 18 Brahman bulls. Of 18 bulls (a) five showed the presence of spot Z₁ and Z₂ (pattern A) (b) one of spot Z₃ (pattern B) (c) five of spot Z₂ and Z₃ (pattern C) (d) one of spot Z₁ (pattern D) and (e) six of spot Z₂ (pattern E). Identification of spot Z₁, Z₂ and Z₃ by LC MS/MS had a similar result as matched to the tektin-4 protein of Bos taurus with a respective score of 171, 557 and 591. The statistical analysis of the 56 kDa protein patterns, tektin-4, indicated a significant effect on spermatozoa motility (P < 0.05) albeit non-significant on spermatozoa morphology. The bulls which showed pattern A had a higher percentage of spermatozoa motility than pattern E (P < 0.05) and not different from pattern C (P > 0.05). The statistical analysis also revealed that the presence of spot Z₁ had an effect on the percentage of spermatozoa motility (P < 0.01), whereas the presence of spot Z₂ and Z₃ had no effect (P > 0.05). The correlation coefficient between the relative protein content of spot Z₁ and the percentage of spermatozoa motility was 0.49. Our study demonstrates that the expression patterns of tektin-4 were a proxy for an effect on spermatozoa motility and consequently bull infertility. It may be that these protein patterns can be used as markers for improving bovine reproduction.