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Association of Silent Variant p.17Pro = SNP in the LHX4 Gene with Litter Size in Awassi Sheep
Tahreer M Al-Thuwaini1, Ahmed H Alkhammas2, Fadhil A Rhadi2
1Department of Animal Production, College of Agriculture, Al-Qasim Green University, Al-Qasim, Babil, Iraq. tahreermohammed@ymail.com.
Abstract:
LIM homeobox transcription factor 4 (LHX4) is one of the genes involved in sheep reproduction. Consequently, this study investigated whether the LHX4 gene affects the litter size of ewes. Genomic DNA extraction was performed on 123 ewes with singleton lambs and 109 ewes with twins. Using polymerase chain reaction (PCR), fragments of 207, 256, 257, 325, and 377 bp were amplified from exons 1, 2, 3, 5, and 6 of the LHX4 gene. Genetic analysis of the amplified locus of 207 bp revealed three genotypes. An analysis of the sequence revealed a novel mutation in exon 1: p.17Pro = SNP. Statistical analysis showed that the p.17Pro = SNP was associated with reproductive characteristics (P ≤ 0.01). Ewes carrying the GG genotype had significantly lower live body weight, litter sizes, twinning rates, lambing rates, and more lambing days than ewes with AG and AA genotypes. Lambs produced by GG genotype ewes were fewer than those produced by AA and AG genotype ewes. These results indicate that the p.17Pro = SNP negatively affects Awassi sheep's reproductive traits. Ewes carrying the GG genotype are less prolific and have lower litter sizes than those without the SNP.
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