Estrogen receptor gene (ESR) and semen characteristics of boars

Abstract. Estrogen receptor gene (ESR) which is localized in the swine chromosome 1, has been recognized as a "candidate" gene of reproductive traits. The aim of this study was to determine the mutations in the ESR/AvaI (ESR1) and ESR/PvuII (ESR2) gene in boars kept at the AI Station and its effect on selected quantitative and qualitative characters of the semen. The study included 217 boars maintained at the AI Station. The ESR genotypes were determined with PCR-RFLP. Two alleles ESR1 were identified: A (109 and 76 bp), B (76, 62 and 47 bp) and also two alleles ESR2: C (120 bp), D (65 and 55 bp), with the frequencies: 0.79 (A), 0.21 (B), 0.83 (C) and 0.17 (D) respectively. In the studied population of boars, the genotype AA was detected with the frequency 0.69, AB-0.21, BB-0.10 of ESR1 and CC-0.72, CD-0.23, DD-0.05 of ESR2.

The analysis showed statistically significant differences (P≤0,01) between boars carrying different ESR1 and ESR2 genotypes and all semen traits.