Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
Faculty of Animal Science and Technology, Yunnan Agricultural University, Kunming 650224, China.
Poult Sci. 2018 Oct 1;97(10):3414-3420. doi: 10.3382/ps/pey232.
Calpain 9 (CAPN9) is expressed in the stomach and small intestine. CAPN9 has regulatory roles in hypertension, heart disease, gastric mucosal defense, and kidney disease. The involvement of CAPN9 has not been reported in the development of chickens. CAPN9 mRNA was found in adipose and muscle tissue in this study. Two linkage single nucleotide polymorphisms (SNP; G7518A and C7542G) in intron 4 were screened from 160 birds of the D2 chicken line. The 2 mutation sites were associated with carcass weight, evisceration weight, abdominal fat weight (AFW), abdominal fat percentage (AFP), and breast muscle percentage (all P < 0.05). Intramuscular fat (IMF) content was not significantly different in the 3 genotypes. But, the AA(7518)/GG(7542) genotype had the highest IMF content, highest breast muscle weight, and lower AFW and AFP. Moreover, the mRNA level of CAPN9 in abdominal fat tissue was significantly different (P < 0.05 or P < 0.01) between any 2 genotypes, consistent with AFW and AFP. In summary, the expression of CAPN9 in adipose and breast muscle tissue is reported for the first time. CAPN9 affected production performance of chickens. As a marker, the linkage G7518A and C7542G polymorphisms in intron 4 of CAPN9 could affect the production traits by regulating mRNA expression. The findings concerning the marker enrich the theoretical foundation for molecular breeding of high-quality broilers.
钙蛋白酶 9（CAPN9）在胃和小肠中表达。CAPN9 在高血压、心脏病、胃黏膜防御和肾脏疾病中具有调节作用。CAPN9 参与鸡的发育尚未见报道。本研究在脂肪组织和肌肉组织中发现了 CAPN9 mRNA。从 D2 鸡系的 160 只鸡中筛选出第 4 内含子中的两个连锁单核苷酸多态性（SNP；G7518A 和 C7542G）。这两个突变位点与胴体重、屠体重、腹脂重（AFW）、腹脂率（AFP）和胸肌率（均 P<0.05）相关。3 种基因型的肌内脂肪（IMF）含量无显著差异。但 AA（7518）/GG（7542）基因型的 IMF 含量最高、胸肌重量最高、AFW 和 AFP 最低。此外，腹脂组织中 CAPN9 的 mRNA 水平在任何 2 种基因型之间差异显著（P<0.05 或 P<0.01），与 AFW 和 AFP 一致。综上所述，首次报道了 CAPN9 在脂肪和胸肌组织中的表达。CAPN9 影响鸡的生产性能。作为一个标记，CAPN9 第 4 内含子中的连锁 G7518A 和 C7542G 多态性可通过调节 mRNA 表达来影响生产性状。该标记的发现丰富了优质肉鸡分子育种的理论基础。
