Identification and isolation of gene differentially expressed on scrotal circumference in crossbreed bulls
Differential display reverse transcription polymerase chain reaction (DDRT-PCR), reverse northern blot analysis and real-time polymerase chain reaction (RT-PCR) were used to identify tissue-specific expression genes in scrotum of differential scrotal circumference bulls and the function of these specific genes on the development of the bull’s scrotum was analyzed in this study. The results indicate that 19 positive fragments were screened out by DDRT-PCR and reverse northern blot analysis. Results of BLAST with GenBank show that three genes or expressed sequence tag (ESTs) were unknown, and there were eight sequences highly identified to be Bos taurus mRNA for proline-rich protein P-B and other sequences were B. taurus ebd-P2 pseudogene, B. taurus similar to F-box only protein 21 isoform 2, B. taurus similar to Kinesin heavy chain isoform 5C, B. taurus similar to ankyrin repeat domain protein 15 isoform and B. taurus similar to galactosidase, beta 1-like. The result of real-time PCR analysis testified more that B. taurus was similar to galactosidase, beta 1-like, kinesin heavy chain isoform 5C and ankyrin repeat domain protein 15 isoform. B. taurus ebd-P2 pseudogene was highly expressed in bulls which had bigger scrotal circumference. They may be involved with sperm maturation in the epididymis, sperm protection and prevention of the ascent of microorganisms into the adjacent testes and also responsible for converting immature sperm into competent functional cells, as well as movement of spermatozoa.
Key words: Bulls, scrotal circumference, differential display reverse transcription polymerase chain reaction (DDRT-PCR), real time polymerase chain reaction (RT-PCR).