The genome of the colonial hydroid Hydractinia reveals their stem cells utilize a toolkit of evolutionarily shared genes with all animals
- Christine E. Schnitzler1,
- E. Sally Chang2,
- Justin Waletich1,
- Gonzalo Quiroga-Artigas1,
- Wai Yee Wong3,
- Anh-Dao Nguyen2,
- Sofia Barreira2,
- Liam B. Doonan4,
- Paul Gonzalez2,
- Sergey Koren2,
- James Gahan4,
- Steven Sanders5,
- Brian Bradshaw4,
- Timothy DuBuc4,
- Febrimarsa Febrimarsa4,
- Danielle de Jong1,
- Eric Nawrocki6,
- Alexandra Larson1,
- Samantha Klasfeld2,
- Sebastian Gornik4,
- R. Travis Moreland2,
- Tyra Wolfsberg2,
- Adam M Phillippy2,
- James Mullikin2,
- Oleg Simakov3,
- Paulyn Cartwright7,
- Matthew Nicotra5,
- Uri Frank4 and
- Andreas D. Baxevanis2,8
Abstract
Hydractinia is a colonial marine hydroid that exhibits remarkable biological properties, including the capacity to regenerate its entire body throughout its lifetime, a process made possible by its adult migratory stem cells, known as i-cells. Here, we provide an in-depth characterization of the genomic structure and gene content of two Hydractinia species, H. symbiolongicarpus and H. echinata, placing them in a comparative evolutionary framework with other cnidarian genomes. We also generated and annotated a single-cell transcriptomic atlas for adult male H. symbiolongicarpus and identified cell type markers for all major cell types, including key i-cell markers. Orthology analyses based on the markers revealed that Hydractinia’s i-cells are highly enriched in genes that are widely shared amongst animals, a striking finding given that Hydractinia has a higher proportion of phylum-specific genes than any of the other 41 animals in our orthology analysis. These results indicate that Hydractinia’s stem cells and early progenitor cells may use a toolkit shared with all animals, making it a promising model organism for future exploration of stem cell biology and regenerative medicine. The genomic and transcriptomic resources for Hydractinia presented here will enable further studies of their regenerative capacity, colonial morphology, and ability to distinguish self from non-self.
- Received August 25, 2023.
- Accepted March 7, 2024.
- Published by Cold Spring Harbor Laboratory Press
This manuscript is Open Access.
This article, published in Genome Research, is available under a Creative Commons License (Attribution 4.0 International license), as described at http://creativecommons.org/licenses/by/4.0/.
