Molecular cloning, sequence identification and expression analysis of novel caprine MYLPF gene

Skeletal muscle genes are important potentially functional candidate genes for livestock production and meat quality. Myosin regulatory light chain (MLC) regulates myofilament activation via phosphorylation by Ca(2+) dependent myosin light chain kinase. The cDNA of the myosin light chain, phosphorylatable, fast skeletal muscle (MYLPF) gene from the longissimus dorsi of Tianfu goat was cloned and sequenced. The results showed that MYLPF full-length coding sequence consists of 513 bp and encodes 170 amino acids with a molecular mass of 19.0 kD. Two EF-hand superfamily domain of MYLPF gene conserved between caprine and other animals. The deduced amino acid sequence of MYLPF shared significant identity with the MYLPF from other mammals. A phylogenetic tree analysis revealed that the caprine MYLPF protein has a close genetic relationship and evolutional distance with MYLPF in other mammals. Analysis by RT-PCR showed that the MYLPF mRNA was detected in heart, liver, spleen, lung, kidney, gastrocnemius, abdominal muscle and longissimus dorsi. In particular, high expression levels of MYLPF mRNA were detected in the longissimus dorsi, gastrocnemius and abdominal muscle, and low level of expressions were observed in liver, spleen, lung and kidney. In addition, the temporal expression analysis further showed MYLPF expression decreased gradually with age in the skeletal muscle. This may be important as muscle growth occurs mainly in young age in goats. Western blotting results detected the MYLPF protein in four of the tissues in which MYLPF was shown to be expressed; the four exceptions were liver, spleen, lung and kidney.