Meeting Abstract
Hydra tissue is very dynamic, with continuous cell displacement, turnover, and replenishment from three lineage-restricted stem cell populations. Interstitial stem cells give rise to the germline, nerves, gland cells, and nematocytes, while cells of the endodermal and epithelial cell lineages can function as stem cells and give rise to the head and foot epithelia. While these populations have been characterized through morphology, transplantation, cellular cloning, transgenesis, and in situ hybridization, their complete transcriptomes remain undefined, and many important questions remain unanswered. For instance, what is the molecular definition of each of these cell types? Do differentiation intermediates exist for each of these stem cell populations, and what are their specific molecular signatures? How many molecularly distinct cell types are present in an adult polyp? To address these questions, we are determining the single cell transcriptomes of all Hydra cells using a droplet based sequencing approach (Drop-seq). Our data reveals which genes are expressed in cells from all lineages and provide insights into their differentiation trajectories. Our approach promises novel insights into diverse areas, such as stem cell decision making, nervous system evolution, and tissue architecture.
