The potential role of Kriippel-like factor 13 (Aj-klf13) in the intestine regeneration of sea cucumber Apostichopus japonicus

Kruppel-like factor13 (klf13), a member of the Kruppel-like factor family, plays a vital role in cell proliferation and differentiation. When sea cucumber Apostichopus japonicus is attacted by predators, it can spit viscera in order to escape attack, and then complete the intestine regeneration process within 15 days. However, the potential role of klf13 from A. japonicus (Aj-klf13) in the intestine regeneration of sea cucumber A. japonicus still remains unknown. In present paper, the full-length cDNA of k1f13 gene from A. japonicus was cloned by RACE techniques, and it was composed of 2496 bp, including a 245 bp 5' UTR, a 1396 bp 3' UTR and a 855 bp open reading frame, which encoded a polypeptide of 284 amino acids and C2H2 zinc finger domains. The expression level of Aj-klf13 showed an increasing trend in intestine regeneration process of sea cucumber, and it reached the highest at 6 days, returning to the normal at 15 days. By western blot, the expression level of Aj-KLF13 protein was basically consistent with that of Aj-klf13 gene. The expression locations of protein by immunofluorescence indicated that Aj-KLF13 was widely expressed in the normal physiological state and intestine regeneration process of sea cucumbers, which was in the nucleus. There was tissue specificity of the protein, which was mainly distributed in luminal epithelium and coelomic epithelium. These results indicate that Aj-klf13 plays a crucial role in the intestine regeneration process of sea cucumber A. japonicus.