Cellular pathways during spawning induction in the starlet sea anemoneNematostella vectensis

In cnidarians, long-term ecological success relies on sexual reproduction. The sea anemone Nematostella vectensis , which has emerged as an important model organism for developmental studies, can be induced for spawning by temperature elevation and light exposure. To uncover molecular mechanisms and pathways underlying spawning, we characterized the transcriptome of Nematostella females before and during spawning induction. We identified an array of processes involving numerous receptors, circadian clock components, cytoskeleton, and extracellular transcripts that are upregulated upon spawning induction. Concurrently, processes related to the cell cycle, fatty acid metabolism, and other housekeeping functions are downregulated. Real-time qPCR revealed that light exposure has a minor effect on expression levels of most examined transcripts, implying that temperature change is a stronger inducer for spawning in Nematostella . Our findings reveal the mechanisms that may enable the mesenteries to serve as a gonad-like tissue for the developing oocytes and expand our understanding of sexual reproduction in cnidarians. Summary statement Analysis of transcriptional changes during spawning induction in Nematostella vectensis , revealed upregulation of processes related to signal perception and cytoskeleton rearrangement and downregulation of fatty acid metabolism and housekeeping processes.