The system be down for regular maintenance on April 3rd, 2024 from 8:00-10:00am.
The Search for Putative Mesoderm and Muscle Specific Genes in Pleurobrachia bachei
Abstract
There has been a long debate in the scientific community over the oldest surviving
metazoan lineage. Traditionally it has been taught that Porifera, the sponges, occupy that nitche
possessing a diploblastic body plan without true organs; however recent phylogentic analysis has
suggests that Ctenophora may truly be the oldest lineage, free floating animals with a possible
mesoderm layer and complex organs. In this study we searched for the presence of mesoderm in
Ctenophora by examining the genome of Pleurobrachia bachei for the presence of tropomyosin,
calponin, and β-catenin. Gene expression for all three were found not only in the muscular
regions of P. bachei, but in the epidermal tissues as well, indicating there is an unknown function
in the metazoan common ancestor. Homology comparisons to the rest of Metazoa reveal little
about tropomyosin and calponin, however the ctenophore β-catenin protein appears to be to least
derived of all metazoans and suggests Ctenophora may be the most basal extant metazoan
lineage.