VARIATION IN THE FORKHEAD BOX CLASS O3 (FOXO3) GENE AND ITS ASSOCIATION WITH LIFESPAN TRAITS IN BARKI EWES

In this study the polymorphisms in exon 2 of ovine Forkhead Box Class O3 (FOXO3) gene were detected in 96 Barki ewes by the polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) analysis. The association of FOXO3 gene polymorphisms with lifespan traits was tested using general linear mixed effect models. Three alleles (A, B and C) were detected with frequencies of 0.57, 0.28 and 0.15, respectively. Also five genotypes (AA, AB, AC, BB and CC) were identified with frequencies of 0.26, 0.44, 0.18, 0.06 and 0.06, respectively. Genotypes of the FOXO3 gene were shown to be associated with age, twining rate, total number of lambs born per ewe (TNLB) and total weight of lambs born per ewe (TWLB). The presence of allele C was associated with longer age and increased TNLB, whereas the presence of allele B was associated with shorter age, increased twining rate and decreased rearing ability and total number of lams weaned per ewe (TNLW). The effect of the number of allele copies present was tested and it was found that the presence of two copies of allele C was associated with longer age and increased TNLB and the presence of two copies of allele B was associated with shorter age, increased twining rate and decreased rearing ability and TNLW. These results suggest that variation in ovine FOXO3 gene is associated with lifespan traits of Barki ewes.