Altwaty Nada H, Salem Lamiaa M, Mahrous Karima F
Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah, Saudi Arabia.
Department of Cell Biology, National Research Centre, Dokki, Giza, Egypt.
Vet World. 2020 May;13(5):884-889. doi: 10.14202/vetworld.2020.884-889. Epub 2020 May 14.
This study aimed to investigate the polymorphisms in genes related to meat production, including growth hormone receptor () and diacylglycerol acyltransferase 1 () genes, in different breeds of sheep, including Barki, Najdi, and Harri.
Blood samples were collected from 75 randomly selected healthy Barki, Najdi, and Harri breeds of sheep, with 25 samples per breed. and genes were identified using a single nucleotide polymorphism assay followed by digestion with the restriction enzyme .
The analysis of the gene sequence showed nucleotide substitutions at nt 69 in exon 10 (c.69 G > A); this mutation is considered a transition mutation. The sequences of detected SNPs in the gene in the different sheep breeds were submitted to the GenBank database with accession numbers MG906773 to MG906781. The substitutions at exon 10 (c.69 G > A) results in an alteration to the amino acid (p. Lysine > Arginine). At c.69, the A allele frequency was 0.61, 0.59, and 0.54, while the G allele frequency was 0.39, 0.41, and 0.46, for Barki, Najdi, and Harri breeds, respectively. The genotype AG at nt 69 locus had the highest frequency in the Najdi and Harri sheep. The frequency of AG was 0.62, 0.61, and 0.64, while the frequency of AA was 0.30, 0.28, and 0.22, for Barki, Najdi, and Harri sheep, respectively. After digestion with the restriction enzyme , the locus had two genotypes, CC and CT. The highest frequency, 0.88, was found for allele C, which was detected in Barki breed. The lowest frequency, 0.75, for the same allele was found for Harri.
The detected CT genotype may explain the moderate intramuscular fat content and muscle marbling in the Barki sheep breed.
本研究旨在调查不同品种绵羊（包括巴基羊、纳吉迪羊和哈里羊）中与产肉相关基因（包括生长激素受体（）和二酰基甘油酰基转移酶1（）基因）的多态性。
从75只随机选取的健康巴基羊、纳吉迪羊和哈里羊品种中采集血样，每个品种25份。使用单核苷酸多态性分析，随后用限制性内切酶消化来鉴定和基因。
基因序列分析显示外显子10中第69位核苷酸发生替换（c.69 G > A）；此突变被认为是转换突变。不同绵羊品种基因中检测到的单核苷酸多态性序列已提交至GenBank数据库，登录号为MG906773至MG906781。外显子10处的替换（c.69 G > A）导致氨基酸改变（p.赖氨酸>精氨酸）。在c.69处，巴基羊、纳吉迪羊和哈里羊品种的A等位基因频率分别为0.61、0.59和0.54，而G等位基因频率分别为0.39、0.41和0.46。在纳吉迪羊和哈里羊中，第69位核苷酸位点的AG基因型频率最高。巴基羊、纳吉迪羊和哈里羊的AG频率分别为0.62、0.61和0.64，而AA频率分别为0.30、0.28和0.22。用限制性内切酶消化后，位点有两种基因型，CC和CT。在巴基羊品种中检测到的等位基因C频率最高，为0.88。在哈里羊中，该等位基因的频率最低，为0.75。
检测到的CT基因型可能解释了巴基羊品种中适度的肌内脂肪含量和肌肉大理石花纹。
