Insulin-like growth factor 1 receptor (IGF-1R) is a main receptor of IGFs family which plays a critical role in the postnatal growth and skeletal growth in many species. However, there are few reports of IGF-1R gene structure and its effects on growth traits in sheep. The objectives of this study were detection of IGF-1R polymorphisms and assessment of their associations with growth traits in Iranian Makooei Sheep. Hence, 200 Makooei lambs were genotyped through polymerase chain reaction-single-strand conformation polymorphism (PCR-SSCP). The studied traits were birth weight (BW), weaning weight (WW), 6 months weight (6MW), average daily gains from birth to 3 months (ADG0-3), from 3 months to 6 months (ADG3-6), from birth to 6 months (ADG0-6) and corresponding Kleiber ratios (KR0-3, KR3-6, KR0-6).For this genetic position, three types of banding patterns (AA, AB and BB) were identified with the frequencies of 0.69, 0.16 and 0.15, respectively. In this study, IGF-1R genotypes indicated the significant associations with 6MW, ADG0-6, KR0-3 (P<0.05) and ADG0-3 (P<0.01). In all of the significant traits, The AAgenotype was linked to the highest values, while the BBgenotype was linked to the lowest values. The results of this study indicated that single nucleotide polymorphism (SNP) variation in IGF-1R gene can be used as a molecular marker for improving of growth traits in marker assisted selection programs in sheep. Manuscript profile

The aim of this study was to investigate effects of DGAT1, OPN and PPARGC1A candidate genes on milk production traits in Iranian Holstein cattle. Several papers have studied single nucleotide polymorphisms (SNPs) and their association with economic traits in dairy cows, but the combined effect of these genes has not been examined in Iranian Holstein cattle population. Blood samples were collected from 398 registered Holstein cows. Total DNA was extracted using the salting out protocol. The PCR-RFLP technique was used for SNPs genotyping. The largest genotype frequency was estimated as 0.65 for PPARGC1A (c.1892)CT and the least frequency was estimated as 0.09 for DGAT1KK genotype. The allele frequencies were in the range 0.36 to 0.64 for PPARGC1A (c.3359)A and Calleles,respectively. The allelic substitution effects were estimated using a multiple regression model. The effects of allelic substitution for DGAT1K and PPARGC1A (c.1892)T were significant on estimated breeding values for fat percentage (EBVFP) (P<0.01). In addition, the results of multivariate analysis indicated the significant effect of DGAT1 and PPARGC1A (c.1892) on EBVFP (P<0.05). However, there were no association between OPN and PPARGC1A (c.3359) polymorphisms and studied traits. Manuscript profile