Biology subjects

Goulty, M.

Publications and source records attributed to Goulty, M..

5 recordsLinked to original sources

bioRxiv2025

Evolutionarily conserved transcriptional regulators control monoaminergic neuron development

To what extent conserved developmental programs specify homologous cell types is a central question in biology. Here, we address this by focusing on reconstructing monoaminergic neuron development in Drosophila melanogaster embryo using time- resolved single-cell genomics, spatial transcript mapping with hybridisation chain reaction, and targeted metabolomics. We uncover a regulatory landscape in which specific transcription factors are activated before biosynthetic enzymes, establishing a prospective temporal architecture for monoaminergic fate specification. Comparative analyses of developmental single-cell atlases from zebrafish and sea urchin indicate that components of this machinery are conserved across [~]550 million years of bilaterian evolution with orthologous transcription factors showing similar temporal dynamics. Together, these findings point to a putatively conserved regulatory core that interfaces with other context-dependent transcription factors; this interplay accommodates monoaminergic multifunction and subtype diversity across distinct neuroanatomies.

evolutionary biology↗

bioRxiv2025

Monoaminergic neurons share transcriptional identity across Bilaterian animals

The evolutionary conservation of cell types over deep time has long been theorised but remains difficult to demonstrate. Monoaminergic neurons, which produce molecules such as serotonin and dopamine, are central to animal behaviour and cognition, yet their evolutionary origins remain unresolved. Here, we analysed single-cell transcriptomes from 16 metazoan species spanning eight phyla. Using a novel integration method, Orthogroup Recoding, together with experimental validation, we show that monoaminergic neurons form consistent transcriptional clusters across Bilateria. These clusters share a regulatory signature involving conserved transcription factors, including homologues of Fev, Lmx1b, Fer2, Insm, and Isl, suggesting a common regulatory program. This signature extends beyond the brain including other monoaminergic cells, such as the gut enterochromaffin cells and larval sensory neurons. By contrast, non-bilaterian lineages lack the coordinated expression of the transcription factors and the biosynthetic machinery that regulate monoamine production. Our observations support the existence of a shared set of TFs that define monoaminergic identity across in bilaterians.

bioinformatics↗

bioRxiv2023

The origin, evolution and molecular diversity of the chemokine system

Chemokine signalling performs key functions in cell migration via chemoattraction, such as attracting leukocytes to the site of infection during host defence. The system consists of a ligand, the chemokine, usually secreted outside the cell, and a chemokine receptor on the surface of a target cell that recognises the ligand. Several non-canonical components interact with the system. These include a variety of molecules that usually share some degree of sequence similarity with canonical components and, in some cases, are known to bind to canonical components and/or to modulate cell migration (1, 2). While canonical components have been described in vertebrate lineages, the distribution of the non-canonical components is less clear. Uncertainty over the relationships between canonical and non-canonical components hampers our understanding of the evolution of the system. We used phylogenetic methods, including gene-tree to species-tree reconciliation, to untangle the relationships between canonical and non-canonical components, identify gene duplication events and clarify the origin of the system. We found that unrelated ligand groups independently evolved chemokine-like functions. We found non-canonical ligands outside vertebrates, such as TAFA "chemokines" found in urochordates. In contrast, all receptor groups are vertebrate-specific and all - except ACKR1 - originated from a common ancestor in early vertebrates. Both ligand and receptor copy numbers expanded through gene duplication events at the base of jawed vertebrates, with subsequent waves of innovation occurring in bony fish and mammals.

evolutionary biology↗

bioRxiv2022

Neuromodulation by Monoamines is a Bilaterian Innovation

Monoamines like serotonin, dopamine, and adrenaline/noradrenaline (epinephrine/ norepinephrine) act as neuromodulators that tune the response of the nervous system to the environment with predictable advantages for fitness. For instance, monoamines influence action selection depending on the internal state of the organism, contribute to higher cognitive functions like learning and memory formation and modulate fundamental homeostatic needs such as sleep or feeding. Despite their significance and the extensive research in model organisms, the evolutionary origin of the monoaminergic system is uncertain. Here using a phylogenomic approach we study the evolution of the majority of genes involved in the production, modulation, and detection of monoamines. Our analyses suggest that most of the genes of the monoaminergic system originated in the common ancestor of bilaterians. These findings suggest that the monoaminergic synaptic pathway is a bilaterian innovation. We hypothesise that monoaminergic neuromodulation contributed to the diversification and complexification of behaviour and forms found in Bilateria.

evolutionary biology↗

bioRxiv2020

The diverging evolutionary history of opsin genes in Diptera

Opsin receptors mediate the visual process in animals and their evolutionary history can provide precious hints on the ecological factors that underpin their diversification. Here we mined the genomes of more than 60 Dipteran species and reconstructed the evolution of their opsin genes in a phylogenetic framework. Our phylogenies indicate that dipterans possess an ancestral set of five core opsins which have undergone several lineage-specific events including an independent expansion of low wavelength opsins in flies and mosquitoes and numerous family specific duplications and losses. Molecular evolutionary studies indicate that gene turnover rate, overall mutation rate, and site-specific selective pressure are higher in Anopheles than in Drosophila; we found signs of positive selection in both lineages, including events possibly associated with their peculiar behaviour. Our findings indicate an extremely variable pattern of opsin evolution in dipterans, showcasing how two similarly aged radiations - Anopheles and Drosophila - can be characterized by contrasting dynamics in the evolution of this gene family.Competing Interest StatementThe authors have declared no competing interest.View Full Text

evolutionary biology↗