Distinct profiles of expressed sequence tags during intestinal regeneration in the sea cucumberHolothuria glaberrima

Abstract

Repair and regeneration are key processes for tissue maintenance, and their disruption may lead to disease states. Little is known about the molecular mechanisms that underline the repair and regeneration of the digestive tract. The sea cucumber Holothuria glaberrima represents an excellent model to dissect and characterize the molecular events during intestinal regeneration. To study the gene expression profile, cDNA libraries were constructed from normal, 3-day, and 7-day regenerating intestines of H. glaberrima. Clones were randomly sequenced and queried against the nonredundant protein database at the National Center for Biotechnology Information. RT-PCR analyses were made of several genes to determine their expression profile during intestinal regeneration. A total of 5,173 sequences from three cDNA libraries were obtained. About 46.2, 35.6, and 26.2% of the sequences for the normal, 3-days, and 7-days cDNA libraries, respectively, shared significant similarity with known sequences in the protein database of GenBank but only present 10% of similarity among them. Analysis of the libraries in terms of functional processes, protein domains, and most common sequences suggests that a differential expression profile is taking place during the regeneration process. Further examination of the expressed sequence tag dataset revealed that 12 putative genes are differentially expressed at significant level ( R > 6). Experimental validation by RT-PCR analysis reveals that at least three genes (unknown C-4677-1, melanotransferrin, and centaurin) present a differential expression during regeneration. These findings strongly suggest that the gene expression profile varies among regeneration stages and provide evidence for the existence of differential gene expression.

Characterization of proteolytic activities during intestinal regeneration of the sea cucumber, Holothuria glaberrima

“…Interestingly, calpain 5 remains significantly high during all process of intestinal regeneration. Additionally, in a previous report we demonstrated the presence of cathepsin C mRNA in cDNA libraries of 3- and 7-dpe regenerating intestines (Rojas-Cartagena et al, 2007). These findings are consistent with the enzymatic assays and support the presence of calpains and cathepsin during intestinal regeneration.…”

Expression of Wnt9, TCTP, and Bmp1/Tll in sea cucumber visceral regeneration

“…We identified the homolog of Bmp1 among 5173 ESTs representing three cDNA libraries from the normal and regenerating digestive tube (Rojas-Cartagena et al, 2007) by BLAST search against the non-redundant NCBI protein database. The full length of the coding region was reconstructed by performing 5' and 3' RACE.…”

Echinodermata

“…These data are incorporated into accessible databases (e.g., EchinoBase: http:// mandolin.caltech.edu/Echinobase/ ). Other echinoderms for which transcriptome data have been generated are the echinoid Heliocidaris erythrogramma (mixed developmental stages) (Wygoda et al 2014 ), the holothurians Holothuria glaberrima (intestinal regeneration) (Rojas-Cartagena et al 2007 ;Du et al 2012 ) and Apostichopus japonicus (mixed developmental stages (Du et al 2012 ) or adult regenerating tissues (Sun et al 2011 )), as well as the ophiuroids Ophiocoma wendtii (gastrula) (Vaughn et al 2012 ) and Amphiura fi liformis (regenerating arms) (Burns et al 2012 ). Many other species are currently being sequenced and analyzed; some of the results are accessible through different websites.…”