Cloning and Tissue Expression Analysis of Creatine Kinase (M-CK) cDNA from the Mandarin Fish，Siniperca chuatsi

The creatine kinase（CK） cDNA from the mandarin fish Siniperca chuatsi was cloned by RT-PCR and rapid amplification of cDNA ends (RACE) methods. The structural characteristics and phylogeny of this gene were analyzed. Sequence analysis revealed a 1 586 bp cDNA sequence containing 92 bp 5′-untranslated region, 348 bp 3′-untranslated region and 1146 bp open reading frame (ORF), which encoded 381 amino acids. Conserved sequence blocks of vertebrate CKs and diagnostic boxes for the muscle CK（M-CK） isozyme were identified in S. chuatsi CK. Siniperca chuatsi CK showed a higher similarity with vertebrates M-CK isozyme than other CK isozymes (Brain CK, Mitochondrial CKs) and grouped with M-CK isozyme in CK phylogeny, which strongly supported that S. chuatsi CK belongs to M-CK isozyme type. Semi-quantitative RT-PCR analysis demonstrated that the M-CK transcript expression varied among the different tissues and was detected at a high level in skin, ovary, kidney, stomach, muscle and heart, but lower in eye, brain and liver.