Identification And Expression Patterns Of Extracellular Matrix-associated Genes Aj-fnia And Aj-tenascin Involved In Regeneration Of Sea Cucumber Apostichopus Japonicus

Sea cucumbers have a strong regenerative capacity. Many important genes involved in the molecular mechanism of regeneration and associated with intercellular signaling pathways of regeneration have been identi?ed. Throughout embryo development, the product of the fibropellin-ia gene forms a layer known as the apical lamina that surrounds the embryo. In some certain period of time during embryonic development, cells can adhere and migrate on the layer. Meanwhile, tenascin have obvious expression during embryonic development and adult normal tissue events such as wound healing and nerve regeneration process and amplification of the tumor tissue cells.In this study, we cloned for the first time full-length cDNAs of fibropellin-ia(1390 bp, encoding a 199 amino acid protein) and tenascin(1366 bp, encoding a 179 amino acid protein) from Apostichopus japonicus(designated Aj-fnia and Aj-tenascin, respectively) using rapid amplification of cDNA ends from Apostichopus japonicus. The structures and characteristics of these two genes were analyzed bioinformatically, and their expression patterns associated with extracellular matrix remodeling in regeneration of A. japonicus were investigated by real-time PCR and in situ hybridization(ISH). Expression levels of Aj-fnia and Aj-tenascin in the regeneration tissues were higher than those in normal tissues. The highest expression levels of Aj-fnia and Aj-tenascin were shown in the intestine and respiratory tree on the 15 th and 20 th day after sea cucumbers were eviscerated. In the body wall, the highest expression levels of Aj-fnia and Aj-tenascin occurred at 35 and 45 min during early regeneration and then emerged between 5 and 7 d again during late regeneration after the body wall was injured. ISH analysis revealed expression of these genes in the body wall, longitudinal muscle, intestine and respiratory tree. These findings suggest that Aj-fnia and Aj-tenascin are crucial genes that play important roles in regeneration of the sea cucumber.