Association of the polymorphism in the 5’ flanking region of the ovine IGF-I gene with growth traits in the Baluchi sheep

Abstract

The insulin-like growth factor 1 (IGF-I) gene has been described in several studies as a candidate gene for growth traits in farm animals. The present preliminary study attempts to establish associations between growth traits and genetic polymorphisms at the 5' flanking region s IGF-I in the Baluchi sheep. The DNA of 102 sheep of the indigenous Iranian Baluchi breed was evaluated. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis of the 5' flanking region (Exon1) of the ovine IGF-I gene revealed three banding patterns (genotypes) named as A/A, A/B and B/B. The evaluation of an association effect between these SSCP patterns with birth weight (BW), weaning weight (WW), and average daily gain from birth to weaning (GBW), weaning to six month (GWS) and from six month to yearling age (GSY) suggest a positive effect of pattern (Genotype) A/B with GBW and weaning weight (WW). Pattern (Genotype) B/B had a superior birth weight when compared to those of individuals with other patterns. Moreover, the A/A pattern (Genotype) appeared favourable for live weight at yearling age. These results confirmed the potential usefulness of this gene in marker-assisted selection programmes for sheep breeding. ________________________________________________________________________________

Study and Identification of Insulin-Like Growth Factor-I Gene Polymorphisms in Zel Sheep Population

“…The observed and expected genotypic and allelic frequencies of IGF-1 gene polymorphisms has been shown in Table 1. Almost the expected genotype frequencies were similar to Tahmoorespur et al (2009). This result suggested that genotype distribution was in the Hardy-Weinberg equilibrium (p<0.01), such as Yilmaz et al (2005).…”

“…Mehmannavaz et al (2010) proved a significant effect of IGF-1 polymorphism on EBVs for milk production traits on Holstein bulls. Tahmoorespur et al (2009) found the positive influence of exon1 in average daily Gain from Birth to Weaning (GBW).…”

Analysis of Candidate Genes for Growth and Milk Performance Traits in the Egyptian Barki Sheep

“…This might also be related to the fact that for some of the SNPs, a low representation of alternative homozygotes was found in the studied population. However, associations of segregating SNPs in IGF1 and DGAT1 with growth, milk, and wool performance traits have been described in various sheep breeds such as Makeoi, Baluchi, Hu, Sarda, and Mehraban [55][56][57][58][59][60][61][62]. These breed differences might be due to artificial selection pressures or housing due to geographical conditions.…”

Effect of the &lt;i&gt;IGF-I&lt;/i&gt; gene polymorphism on growth, body size, carcass and meat quality traits in Coloured Polish Merino sheep

“…However, there have been only a few association analyses of the IGF-I gene polymorphism with growth traits in sheep. For example, , Tahmoorespur et al (2009), Negahdary et al (2013) and Gholibeikifard et al (2013) observed significant effects of the IGF-I gene polymorphism on several growth traits in Makooei and Baluchi sheep. Moreover, investigated the association of nucleotide substitution in the IGF-I gene with several body size traits in sheep.…”