Whole Tribolium castaneum embryo culture gives insights into the role of FGF signaling pathway during body segmentation in arthropods

Abstract

Introduction: The segmentation is a process that occurs from the posterior part of the body in some animal phyla, like annelids, vertebrates and arthropods. Segment formation relies on molecular oscillators based on dynamic expression patterns. A recent discovery shows this mechanism is shared by vertebrates and arthropods, providing a good argument to propose a segmented common ancestor between them. Most described pathways involved in vertebrate body plan segmentation are Notch- Delta, Wnt and FGF, which are also implicated in very different processes during embryonic development. In arthropods, the role of FGF pathway in posterior segmentation is not known, and this lack of data maintains the question if this molecular pathway has the same role in arthropods as in vertebrates. Methods: Transgenic GFP Tribolium castaneum embryo culture under different conditions, at different defined time and in-situ hybridization. Results: We have analysed the segmentation process measuring the length of bisected embryos incubated with SU5402, an inhibitor of the single Tribolium FGF receptor. We are estimating the change on segmentation patterns by in situ hybridization using the two oscillatory genes known in Tribolium, odd-skipped and even-skipped, as well as the mesoderm marker twist. Discussion: We are proposing that this molecular pathway is involved in arthopod elongation and/or segmentation as in vertebrates. Because the relationship between ectoderm and mesoderm segmentation is not clear, we are also checking the possible participation of FGF signalling pathway in this topic.