Identification and localization of growth factor genes in the sea cucumber.

The sea cucumber is both an economically important species in Asian countries and an emerging experimental model for research studies in regeneration and medicinal bioactives. Growth factors and their receptors are known to be key components that guide tissue repair and renewal, yet validation of their presence in has not been established. We performed a targeted search of transcriptome data to elucidate conserved growth factor family and receptor genes. In total, 42 transcripts were identified, of which 9 were validated by gene cloning and sequencing. The growth factor genes, such as () () () and (), were selected for further analyses, including phylogenetic comparison and spatial gene expression using RT-PCR and hybridization. Expression of all genes investigated were widespread in multiple tissues. However, and were found extensively in the radial nerve cord cells, while was highly expressed in connective tissue layer of the body wall. Our identification and expression analysis of the growth factor genes provided the molecular information of growth factors in this species which may ultimately complement the research in regenerative medicine.