Kim J M, Choi B D, Kim B C, Park S S, Hong K C
Division of Biotechnology, College of Life Sciences and Biotechnology, Korea University, Seoul, South Korea.
J Anim Breed Genet. 2009 Apr;126(2):134-41. doi: 10.1111/j.1439-0388.2008.00724.x.
Pig breeding is aimed at improving lean meat production ability as well as meat quality, and muscle fibre characteristics may be important for enhancing these traits. Therefore, new molecular markers have been demanded for selecting lean meat production ability and meat quality in live animals. Myogenin belongs to the MyoD gene family, and is a candidate gene responsible for muscle fibre characteristics. We identified a new single nucleotide polymorphism (SNP) site in the 5' upstream region of the myogenin gene (nucleotides C and T). A total of 252 pigs of three breeds were genotyped by polymerase chain reaction-restriction fragment length polymorphism using BspCNI. Additionally, they were genotyped for the previously detected MspI site in the 3'-flanking region (alleles A and B). The CCBB diplotype had the highest frequency over breeds, followed by TCBB and CCAB. The other diplotypes were not found in studied pigs. Association analysis performed for the markers found that the TCBB diplotype has desirable effects on the total number of fibres (p < 0.002), fibre cross-sectional area (p < 0.06), and loin eye area (p < 0.001) than the other diplotypes. Moreover, the diplotype had the highest muscle pH value (p < 0.07) and all meat quality traits were near the upper limit of the normal range as a reddish pink, firm and non-exudative (RFN) pork. Therefore, we suggest that selection for the myogenin diplotypes could improve total muscle fibre number, size and lean meat production ability with good meat quality.
猪育种旨在提高瘦肉生产能力以及肉质，而肌纤维特性可能对增强这些性状很重要。因此，需要新的分子标记来在活体动物中选择瘦肉生产能力和肉质。肌细胞生成素属于MyoD基因家族，是负责肌纤维特性的候选基因。我们在肌细胞生成素基因的5'上游区域（核苷酸C和T）鉴定出一个新的单核苷酸多态性（SNP）位点。使用BspCNI通过聚合酶链反应-限制性片段长度多态性对三个品种的252头猪进行了基因分型。此外，对先前在3'侧翼区域检测到的MspI位点（等位基因A和B）进行了基因分型。CCBB双倍型在各品种中的频率最高，其次是TCBB和CCAB。在所研究的猪中未发现其他双倍型。对这些标记进行的关联分析发现，与其他双倍型相比，TCBB双倍型对纤维总数（p < 0.002）、纤维横截面积（p < 0.06）和腰大肌面积（p < 0.001）有理想影响。此外，该双倍型的肌肉pH值最高（p < 0.07），并且所有肉质性状均接近正常范围的上限，呈微红粉色、质地坚实且无渗出（RFN）猪肉。因此，我们建议选择肌细胞生成素双倍型可以改善总肌纤维数量、大小和瘦肉生产能力，并具有良好的肉质。
