Biology subjects

Daly, C. M.

Publications and source records attributed to Daly, C. M..

4 recordsLinked to original sources

bioRxiv2026

IL-17 producing tissue-resident memory T-cells expanded during Staphylococcus aureus nasal colonisation provide heterologous immune protection.

Staphylococcus aureus persistently colonises the nasal tissue (NT) of a significant proportion of the population. The long-lasting impact that asymptomatic S. aureus exposure has on immune memory at colonised barrier sites is incompletely understood, potentially impacting vaccine responsiveness in a pre-exposed population. Tissue resident memory (TRM) cells are long-lived T-cells which remain poised at barrier sites for localised reactivation following antigen exposure. This study demonstrates an increase in NT CD4+ and {gamma}{delta}+ TRM cells in response to S. aureus colonisation, which undergo expansion and IL-17 production upon secondary S. aureus exposure. Interestingly, these cells were also capable of non-specific reactivation, with IL-17+ TRM cells in S. aureus colonised mice enhancing protection against K. pneumoniae infection. Ex-vivo data suggest that non-specific CD4+ TRM cell re-activation is pro-inflammatory cytokine dependent, but antigen independent. Overall, these findings demonstrate that S. aureus nasal colonisation shapes long-lasting TRM cell responses in the NT, which have the potential for non-specific bystander reactivation during subsequent heterologous infection.

immunology↗

bioRxiv2023

Nematostella vectensis exemplifies the exceptional expansion and diversity of opsins in the eyeless Hexacorallia

BackgroundOpsins are the primary proteins responsible for light detection in animals. Cnidarians (jellyfish, sea anemones, corals) have diverse visual systems that have evolved in parallel with bilaterians (squid, flies, fish) for hundreds of millions of years. Medusozoans (e.g. jellyfish, hydroids) have evolved eyes multiple times, each time independently incorporating distinct opsin orthologs. Anthozoans (e.g. corals, sea anemones,) have diverse light-mediated behaviors and, despite being eyeless, exhibit more extensive opsin duplications than medusozoans. To better understand the evolution of photosensitivity in animals without eyes we increased anthozoan representation in the phylogeny of animal opsins and investigated the large but poorly characterized opsin family in the sea anemone Nematostella vectensis. ResultsWe analyzed genomic and transcriptomic data from 16 species of cnidarians to generate a large opsin phylogeny (708 sequences) with the largest sampling of anthozoan sequences to date. We identified 29 opsins from N. vectensis (NvOpsins) with high confidence, using transcriptomic and genomic datasets. We found that lineage-specific opsin duplications are common across Cnidaria, with anthozoan lineages exhibiting among the highest numbers of opsins in animals. To establish putative photosensory function of NvOpsins, we identified canonically conserved protein domains and amino acid sequences essential for opsin function in other animal species. We show high sequence diversity among NvOpsins at sites important for photoreception and transduction, suggesting potentially diverse functions. We further examined the spatiotemporal expression of NvOpsins and found both dynamic expression of opsins during embryonic development and sexually dimorphic opsin expression in adults. ConclusionsThese data show that lineage-specific duplication and divergence has led to expansive diversity of opsins in eyeless cnidarians, suggesting opsins from these animals may exhibit novel biochemical functions. The variable expression patterns of opsins in N. vectensis suggest opsin gene duplications allowed for a radiation of unique sensory cell types with tissue-and stage-specific functions. This diffuse network of distinct sensory cell types could be an adaptive solution for varied sensory tasks experienced in distinct life history stages in Anthozoans.

evolutionary biology↗

bioRxiv2021

Cephalopod Retinal Development Shows Vertebrate-like Mechanisms of Neurogenesis

Neurogenesis, the regulation of cellular proliferation and differentiation in the developing nervous system, is the process that underlies the diversity of size and cell type found in animal nervous systems. Our understanding of how this process has evolved is limited because of the lack of high resolution data and live-imaging methods across species. The retina is a classic model for the study of neurogenesis in vertebrates and live-imaging of the retina has shown that during development, progenitor cells are organized in a pseudostratified neuroepithelium and nuclei migrate in coordination with the cell cycle along the apicobasal axis of the cell, a process called interkinetic nuclear migration. Eventually cells delaminate and differentiate within the boundaries of the epithelium. This process has been considered unique to vertebrates and thought to be important in maintaining organization during the development of a complex nervous system. Coleoid cephalopods, including squid, cuttlefish and octopus, have the largest nervous system of any invertebrate and convergently-evolved camera-type eyes, making them a compelling comparative system to vertebrates. Here we have pioneered live-imaging techniques to show that the squid, Doryteuthis pealeii, displays cellular mechanisms during cephalopod retinal neurogenesis that are hallmarks of vertebrate processes. We find that retinal progenitor cells in the squid undergo interkinetic nuclear migration until they exit the cell cycle, we identify retinal organization corresponding to progenitor, post-mitotic and differentiated cells, and we find that Notch signaling regulates this process. With cephalopods and vertebrates having diverged 550 million years ago, these results suggest that mechanisms thought to be unique to vertebrates may be common to highly proliferative neurogenic primordia contributing to a large nervous system.

developmental biology↗

bioRxiv2021

Co-option of the Limb Patterning Program in Cephalopod Lens Development

Across the Metazoa, similar genetic programs are found in the development of analogous, independently evolved, morphological features. The functional significance of this reuse and the underlying mechanisms of co-option remain unclear. Here we identify the co-option of the canonical bilaterian limb pattering program redeployed during cephalopod lens development, a functionally unrelated structure. We show radial expression of transcription factors SP6-9/sp1, Dlx/dll, Pbx/exd, Meis/hth, and a Prdl homolog in the squid Doryteuthis pealeii, similar to expression required in Drosophila limb development. We assess the role of Wnt signaling in the cephalopod lens, a positive regulator in the developing limb, and find the regulatory relationship reversed, with ectopic Wnt signaling leading to lens loss. This regulatory divergence suggests that duplication of SP6-9 in cephalopods may mediate this co-option. These results suggest that the limb network does not exclusively pattern appendage outgrowth but is performing a more universal developmental function: radial patterning.

developmental biology↗