UA Integrative Systems Neuroscience Seminar Series Presents Arianna Tamvacakis

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Arianna Tamvacakis

The UA Integrative Systems Neuroscience Seminar Series presents Postdoctoral Fellow Arianna Tamvacakis of the Nakanish Lab from the Department of Biological Sciences. Tamvacakis' talk entitled "The evolutionarily conserved transcription factor POU-IV is required for mechanoreceptor cell differentiation and touch-response behavior in the sea anemone Nematostella" will be given virtually at noon on Thursday, Oct. 8.

Abstract: The ability to sense mechanical stimuli is crucial for survival, but do disparate animal species share similar mechanisms for mechanoreceptor cell development and mechanosensation? Amongst vertebrates and some other bilaterian species, a cell type known as a hair cell transduces certain mechanical stimuli through movement of its stereocilia. The evolutionarily conserved transcription factor POU-IV (Brn3) is required in mammals for both embryonic hair cell stereocilia formation and adult mechanosensation.

The sea anemone Nematostella vectensis is a member of Cnidaria, a sister group to Bilateria. Its tentacles respond to mechanical stimuli, and contain a stereocilia-bearing cell type which is morphologically similar to vertebrate hair cells. We found that developing Nematostella tentacular hair cells expressed POU-IV. However, whether cnidarian and vertebrate hair cells share other common features was unclear.

We established a POU-IV CRISPR knockout line, and found that knockout animal hair cells lacked stereocilia rootlets. Knockout animals were significantly less responsive to mechanical stimuli compared with non-mutant littermates. A comparison between published Nematostella transcriptomes from POU-IV mutants and their littermates, in combination with two Nematostella cell-specific transcriptomes, revealed that differential expression of vertebrate hair cell gene homologues correlated with presence of POU-IV in cell populations which included hair cells.

Thus, there was a correlation between POU-IV expression, specific cell type morphology, hair cell marker gene expression, and mechanosensory behavior. The presence of shared features between cnidarian and vertebrate hair cells sheds light on a means by which an evolutionarily conserved transcription factor can affect sensory ability across distantly related species.

The event is free and open to the public. Faculty, postdocs, grad students and undergrads are welcome! To join, go to Zoom log-in.