Cnidarian chimeras as a model for interspecies cell exchange

How cells contribute to tissues across species barriers is a fundamental question in development, evolution and human regenerative biology. Vertebrate models of interspecies chimerism are limited by high cost, low efficiency, ethical concerns and the limited ability to study outcomes in vivo. This project develops a tractable alternative model using the colonial cnidarians Hydractinia symbiolongicarpus and Podocoryna carnea. These organisms exhibit natural intraspecies fusion/rejection governed by known allorecognition genes. My preliminary data show that transient interspecies chimerism occurs, opening the possibility of establishing stable interspecies chimeras. We will combine colony interaction assays, live imaging, flow cytometry and cell staining to analyse fusion/rejection events at a molecular and cellular level. In parallel we will use bulk RNA sequencing to identify targets for genetic manipulation that may facilitate stable interspecies chimerism. Finally, combining cytometry and imaging with a novel single-cell sequencing technique we will assess cell sharing across the species barrier and identify molecular regulators. Ultimately, this project will deliver a low-cost, experimentally tractable in vivo model for studying how cells from one species develop inside of another species, providing insights into stem cell-niche interactions, developmental plasticity and immune barriers. This will serve as a platform for my future independent research program.