Cell type diversity in a developing octopus brain

Abstract

Octopuses are mollusks that have evolved intricate neural systems comparable with vertebrates in terms of cell number, complexity and size. The cell types within the octopus brain that control their amazingly rich behavioral repertoire are still unknown. Here we profile cell diversity of the paralarval Octopus vulgaris brain to build a comprehensive cell type atlas that comprises mostly neural cells, as well as multiple glial subtypes, endothelial cells and fibroblasts. Moreover, we spatially map cell types within the octopus brain, including vertical and optic lobe cell types. Investigation of cell type conservation reveals a shared gene signature between glial cells of mice, fly and octopus. Genes related to learning and memory are enriched in vertical lobe cells, which show molecular similarities with Kenyon cells in Drosophila. Taken together, our data sheds light on cell type diversity and evolution of the complex octopus brain.

A single-cell atlas of bobtail squid visual and nervous system highlights molecular principles of convergent evolution

“…However, their swimming and predatory behavior becomes more refined with age (Darmaillacq et al, 2014; Villanueva et al, 1997), which may be reflected in the possible maturation process that we observe. Interestingly, two recent preprints (Duruz et al, 2022; Styfhals et al, 2022) describe the cell types in the head of hatchling and embryos of two distinct cephalopod species, and their cell clustering, show similarities with what we observe in the optic lobe at the hatchling stage. Such a change in cell type complement is reminiscent of the situation reported in the Drosophila ‘optic lobe’ which is not related either evolutionarily or embryologically to the cephalopod optic lobes (Ma et al, 2012).…”

Optimization of Whole Mount RNA Multiplexed in situ Hybridization Chain Reaction With Immunohistochemistry, Clearing and Imaging to Visualize Octopus Embryonic Neurogenesis

“…For instance, the respective protein can be secreted, which means that mRNA could be detected in a different location than the protein. Our data confirmed previous findings using HCR v3.0 on transverse sections ( Deryckere et al, 2021 ; Styfhals et al, 2022 ) and showed the power of this technique to map marker gene expression in 3D during organogenesis.…”

Optimization of Whole Mount RNA multiplexed in situ Hybridization Chain Reaction with Immunohistochemistry, Clearing and Imaging to visualize octopus neurogenesis

“…Ov-elav expression visualized the central brain masses, optic lobes, stellate, mouth and gastric ganglia as well as the neurons in the arms, while Ov-apolpp was mainly expressed within the neuropil located in the central brain, optic lobes and arms (Figure 3). The expression of Ov-elav and Ov-apolpp observed in whole mount octopus embryos matches the expression data seen on transverse sections (Deryckere et al, 2021;Styfhals et al, 2022). The z-stack overview and 3D view of the multiplexed HCR of Ov-elav and Ov-apolpp is provided in the Supplementary Information (Supplementary Video V2-4).…”

“…We also include immunohistochemistry to prove that sequential detection of mRNA and protein is feasible using our combined method. Our data confirmed previous findings using HCR v3.0 on transverse sections (Deryckere et al ., 2021; Styfhals et al ., 2022) and showed the power of this technique to map phases of organogenesis in 3D.…”