| 研究実績の概要 |
In the third year, I was focusing on analyzing two new lophotrochozoan genomes, namely a ribbon worm (the nemertean Notospermus geniculatus) and a horseshoe worm (the phoronid Phoronis australis). Based on molecular phylogeny, these two animals are closely related to the brachiopod Lingula anatina. By using comparative genomics, I showed that bilaterian ancestors contained a core set of gene families that are shared by extant deuterostomes and lophotrochozoans. From the transcriptomic analysis, I provided evidence that a conserved bilaterian anterior patterning system is retained in lophotrochozoans.
In addition, I was working on the dorsal-ventral (DV) patterning of Lingula embryos. This project is mainly to understand the evolution of brachiopod body plans and the role of BMP signals in neural induction. BMP signaling is essential in axial patterning and determination of cell fate during early embryogenesis in animals. Interactions between BMP ligands and their antagonists, such as chordin and admp, establish the BMP gradients, which subsequently subdivide the embryos into distinct territories and organize body axes. I provided a functional analysis of DV patterning under the control of BMP signaling in the Lingula embryos. Using small-molecule drugs and recombinant proteins together with deep RNA sequencing, I demonstrated that BMP signaling is required for the folding of mantle lobes along the larval anterior-posterior axis. My findings reveal a conserved function of BMP gradients in brachiopods comparable to that of basal deuterostomes.
|
