Identification and characterization of matrix metalloproteinase-13 sequence structure and expression during embryogenesis and infection in channel catfish (Ictalurus punctatus)

Matrix metalloproteinase-13 (MMP-13), referred to as collagenase-3, is a proteolytic enzyme that plays a key role in degradation and remodelling of host extracellular matrix proteins. The objective of this study was to characterize the MMP-13 gene in channel catfish, and to determine its pattern of expression in various healthy tissues and during embryogenesis. Since MMP-13 has been shown to have importance in tissue remodelling and some pathological processes, we further studied its involvement in the defense responses of catfish after bacterial infection. The channel catfish MMP-13 cDNA contains an open reading frame of 1416 bp encoding 471 amino acids. Using RT-PCR analysis, MMP-13 was widely expressed in various health tissues. Using quantitative real-time PCR analysis, expression of MMP-13 gene was up-regulated by bacterial infection. During normal embryological development, MMP-13 expression was slightly increased in the first day post-fertilization and sharply up-regulated from 1-day post-fertilization through hatching.