Whole-animal multiplexed single-cell RNA-seq reveals transcriptional shifts across <i>Clytia</i> medusa cell types

We present an organism-wide, transcriptomic cell atlas of the hydrozoan medusa <i>Clytia hemisphaerica</i> and describe how its component cell types respond to perturbation. Using multiplexed single-cell RNA sequencing, in which individual animals were indexed and pooled from control and perturbation conditions into a single sequencing run, we avoid artifacts from batch effects and are able to discern shifts in cell state in response to organismal perturbations. This work serves as a foundation for future studies of development, function, and regeneration in a genetically tractable jellyfish species. Moreover, we introduce a powerful workflow for high-resolution, whole-animal, multiplexed single-cell genomics that is readily adaptable to other traditional or nontraditional model organisms.