Specification of distinct cell types in a sensory-adhesive organ for metamorphosis in theCionalarva

Abstract

The papillae of tunicate larvae contribute sensory, adhesive, and metamorphosis-regulating functions that are crucial for the biphasic lifestyle of these marine, non-vertebrate chordates. We have identified additional molecular markers for at least five distinct cell types in the papillae of the model tunicateCiona,allowing us to further study the development of these organs. Using tissue-specific CRISPR/Cas9-mediated mutagenesis and other molecular perturbations, we reveal the roles of key transcription factors and signaling pathways that are important for patterning the papilla territory into a highly organized array of different cell types and shapes. We further test the contributions of different transcription factors and cell types to the production of the adhesive glue that allows for larval attachment during settlement, and to the processes of tail retraction and body rotation during metamorphosis. With this study, we continue working towards connecting gene regulation to cellular functions that control the developmental transition between the motile larva and sessile adult ofCiona.

A change incis-regulatory logic underlying obligate versus facultative muscle multinucleation in chordates

“…Library preparation was at the Georgia Tech Molecular Evolution Core Facility as previously described (Johnson et al, 2023), and sequenced on the Illumina NovaSeq 6000 with an SP PE100bp run. Reads were processed and differential gene expression analysis was performed using DESeq2 in Galaxy as previously described (Johnson et al, 2023).…”

“…Library preparation was at the Georgia Tech Molecular Evolution Core Facility as previously described (Johnson et al, 2023), and sequenced on the Illumina NovaSeq 6000 with an SP PE100bp run. Reads were processed and differential gene expression analysis was performed using DESeq2 in Galaxy as previously described (Johnson et al, 2023). KY21 gene model ID numbers (Satou et al, 2022) were matched to KH gene model ID numbers (Satou et al, 2008) using the Ciona Gene Model Converter application: https://github.com/katarzynampiekarz/ciona_gene_model_converter (Johnson et al, 2023).…”

“…Reads were processed and differential gene expression analysis was performed using DESeq2 in Galaxy as previously described (Johnson et al, 2023). KY21 gene model ID numbers (Satou et al, 2022) were matched to KH gene model ID numbers (Satou et al, 2008) using the Ciona Gene Model Converter application: https://github.com/katarzynampiekarz/ciona_gene_model_converter (Johnson et al, 2023). Our RNAseq analysis was also compared to published microarray analysis of Ebf perturbations in FACS-isolated cardiopharyngeal lineage cells (Razy-Krajka et al, 2014).…”

Sensory cells in tunicates: insights into mechanoreceptor evolution

“…There are two dorsal papillae (one left, one right) and one medial ventral papilla ( Figures 2A, B ). Each papilla contains exactly 4 PNs, and additional cell types with proposed adhesive and/or sensory functions ( Zeng et al, 2019 ; Johnson et al, 2023b ). PNs are also found in species with complex eversible papillae (e.g., Diplosoma spp.)…”

Ascidian gene regulation and bioadhesion

“…Ciona sensory adhesive papillae(Figure 2a,b;Zeng, Wunderer, Salvenmoser, Ederth, et al, 2019) as well as adhesive components and markers of the adhesive material that these cells secrete at the time of larval settlement(Zeng, Wunderer, Salvenmoser, Hess, et al, 2019), and collaborated with another group on the specification of papillar cells(Johnson et al, 2023). Presently, we are determining the molecular compositionof the larval glue in three ascidians and performed Phallusia long-read genome sequencing to resolve repeated regions (unpublished).…”