Georgia Journal of Science


Sea urchin pigment cells are single cells of mesodermal origin embedded in the aboral ectoderm. Strongylocentrotus purpuratus polyketide synthase 1 (Sp-PKS1) is required for the biosynthesis of the echinochrome pigment. Evidence suggests that pigment cells are immune cells. In order to reconstruct the gene regulatory network of pigment cells a bottom-up approach combined with comparative genomics has been used in this study. We compared the cis-regulatory regions of five pigment cell genes, Sp-Pks1, flavin monooxygenase 1, 2, and 3 (Sp-Fmo) and sulfotransferase (Sp-Sult), across three different species, Strongylocentrotus purpuratus, Mesocentrotus franciscanus, and Strongylocentrotus fragilis. The computational tool used was multiple expectation maximization motif elicitation analysis. Thirty cis-regulatory motif candidates were identified, three of which were considered for further analysis. The functionality of these motifs was tested by injecting embryos with a -2KbPks-Gfp DNA construct having one of the three motifs mutagenized. All three motifs resulted to be functional cis-regulatory sequences. Specifically, they contained DNA-binding sites for transcriptional activators of Sp-Pks1.


The project described was supported by the NIH award number R15HD060008 from the Eunice Kennedy Shriver National Institute Of Child Health and Human Development. The authors have no conflict of interest to declare.