Axial Patterning in Embryogenesis, Regeneration, and Asexual Reproduction

Trustees Of Boston University, Boston

Investigators

Abstract

0212773 Finerty Every person that has ever walked the earth developed from an embryo. However, many animals such as sea anemones can develop by three alternate developmental pathways: from an embryo (embryogenesis), from a piece of an adult that has been fragmented by injury (regeneration), or from an autonomously produced offshoot of an adult (asexual reproduction). How are three alternate developmental pathways encoded in the genomes of animals such as sea anemones? Why is this kind of developmental flexibility lacking in animals such as humans? Answers to these fundamental questions will come from understanding the similarities and differences between embryogenesis, regeneration, and asexual reproduction at the molecular level. Towards this end, the Finnerty lab will compare the roles of specific axial patterning genes in sea anemones during embryogenesis, regeneration, and asexual reproduction. Axial patterning is the process whereby an animal's body is divided into distinct regions along its primary axis. For example, the relatively simple body of a sea anemone has three main regions: a head, a central body column, and a foot. Importantly, axial patterning is a process that must be performed during embryogenesis, regeneration, and asexual reproduction. This study seeks to reveal whether conserved molecular mechanisms are used to accomplish axial patterning in these alternate pathways. The following specific questions will be addressed. (1) Are the same genes used to accomplish axial patterning in each developmental pathway? (2) Are the temporal and spatial patterns of gene expression consistent between pathways? (3) What are the consequences for embryogenesis of "turning off" a given gene by experimental means? To address questions one and two, the expression of several homeobox transcription factors will be assayed using the techniques of in situ hybridization and quantitative RT-PCR. To address question three, gene expression will be "silenced" using the technique of RNA interference.