The Role and Function of the Notch Signaling Pathway in Early Segmentation in Tribolium castaneum

Abstract

The way in which arthropods construct their body plans is determined by the method of segmentation that they utilize. In more ancestrally located animals on the phylogenetic tree such as Oncopeltus and Thamnocephalus, there generally seems to be an overarching use of the Notch signaling pathway in order to develop properly. However, in more evolutionarily derived organisms such as Drosophila and Tribolium, a different segmentation clock has been proposed to be solely used, termed the pair-rule oscillator. While there is some evidence that Notch signaling has no effect on the segment addition of the model organism Tribolium castaneum, there has also been data supporting the use of Notch signaling on embryonic patterning. In order to further investigate its role, RNAi of Delta, a Notch signaling protein, and in situ hybridization of Notch and Delta was performed. Multiple phenotypes such as a deformation of mouthparts, lack of midline segmentation, and abnormal head development were observed. While our results are currently inconclusive, there are promising similarities in conjunction with published data that lead us to believe that Notch signaling may, in fact, be involved in Tribolium segmentation.