The Hedgehog Signaling Pathway in Isodiametra Pulchra and Stenostomum Virginianum

Abstract

The purpose of this study is to compare the Hedgehog Signaling Pathway (Hh) in the acoelmorphan, Isodiametra pulchra (Ipul) and the flatworm Stenostomum virginianum (Svirg). The former occupies a primitive placement in the bilaterians, while the latter is place in a primitive position in the flatworms. Certain organisms are cilia‐dependent in their Hedgehog signaling, while others conduct signaling independently of cilia. Protostomes (Svirg), for example, have cilium‐independent signaling, whereas deuterostomes (Ipul) require cilia to conduct signaling. Proteins associated with the Hh pathway were identified from the unpublished (Univ. of Innsbruck) transcriptome for Ipul, including orthologues for Hedgehog and multiple possible orthologues for Patched. Primers have been designed and tested to verify the existence of the transcripts listed. The transcriptomic sequences of wild‐type animals (NC coast) displayed both synonymous and non‐synonymous mutations when compared to the transcriptome of the animals cultured in Innsbruck. Next, qPCR primers will be designed and tested to analyze Patched expression, since it is a marker for Hh signaling. Animals treated with cyclopamine, a Hh pathway inhibitor, should display a reduction in Patched expression; this technique will allow us to identify the correct Patched orthologue. The Hh pathway plays a critical role in development in many organisms, including humans. The importance of this study is to establish the relationship between the Hh pathway and cilia. This can ultimately lead to control of abnormalities associated with both cilia and the Hh pathway, and prevent disorders in humans. Funded by SC‐INBRE.