Biology subjects

Hervas-Sotomayor, F.

Publications and source records attributed to Hervas-Sotomayor, F..

5 recordsLinked to original sources

bioRxiv2026

An ancestral pronephric contribution reveals the multilineage origin of the teleost gonad and revises the evolution of vertebrate gonadogenesis

Challenging the paradigm that pronephric field contribution to gonadal formation would be an amniote innovation, we demonstrate this trait is ancestral to bony vertebrates. Using cell lineage tracing, single-cell and spatial transcriptomics, and functional validation, we show that the teleost gonad arises from three distinct embryonic tissues, the pronephros, the coelomic epithelium, and the lateral plate mesoderm, in contrast to amniotes. This multi-tissue origin generates an unexpected lineage-based cellular diversity. Further cross-species comparisons over medaka, mouse, chicken and turtle unravel how lineage-specific deviations shape early gonadal development. Specifically, we map these variations amongst the different gene regulatory networks, outlining their physiological implications for specialized gonadal functions. Our results support a model in which heterochronic shifts are coupled to regulatory rewiring of conserved gene networks, driving lineage-specific developmental trajectories through a canalized developmental system drift.

developmental biology↗

bioRxiv2024

Developmental origins and evolution of pallial cell types and structures in birds

The advanced cognitive abilities of birds rival those of mammals and have been attributed to evolutionary innovations in the pallium. However, a comprehensive cellular characterization of this brain region in birds has been lacking. We scrutinized the structures, cell types and evolutionary origins of the avian pallium based on single-cell and spatial transcriptomics atlases for the adult and developing chicken, and comparisons to corresponding data from mammals and non-avian reptiles. We found that the avian pallium shares most inhibitory neuron types with other amniotes. While excitatory neuron repertoires in the (medial) hippocampal formation show high conservation, they substantially diverged in other pallial regions during avian evolution, defining novel structures like the avian-specific (dorsal) hyperpallium, whose neuronal gene expression identities partly converge during late development with those of the (ventral) nidopallium. Our work also unveils the evolutionary relationships of pallial structures across amniotes, like the previously unknown homology between avian (lateral) mesopallial and mammalian deep layer cortical neurons. One-Sentence SummaryAn avian neural cell type atlas illuminates the developmental origins and evolution of the amniote pallium.

evolutionary biology↗

bioRxiv2024

A single-nucleus RNA sequencing atlas of the postnatal retina of the shark Scyliorhinus canicula

The retina, whose basic cellular structure is highly conserved across vertebrates, constitutes an accessible system for studying the central nervous system. In recent years, single-cell RNA-sequencing studies have uncovered cellular diversity in the retina of a variety of species, providing new insights on retinal evolution and development. However, similar data in cartilaginous fishes, the sister group to all other extant jawed vertebrates, are still lacking. Here, we present a single-nucleus RNA-sequencing atlas of the postnatal retina of the catshark Scyliorhinus canicula, consisting of the expression profiles for 17,438 individual cells from three female, juvenile catshark specimens. Unsupervised clustering revealed 22 distinct cell types comprising all major retinal cell classes, as well as retinal progenitor cells (whose presence reflects the persistence of proliferative activity in postnatal stages in sharks) and oligodendrocytes. Thus, our dataset serves as a foundation for further studies on the development and function of the catshark retina. Moreover, integration of our atlas with data from other species will allow for a better understanding of vertebrate retinal evolution.

neuroscience↗

bioRxiv2024

FEVER: An interactive web-based resource for evolutionary transcriptomics across fishes

Teleost fish represent one of the largest and most diverse clades of vertebrates, which makes them great models in various research areas such as ecology and evolution. Recent sequencing endeavors provided high-quality genomes for species covering the main fish evolutionary lineages, opening up large-scale comparative genomics studies. However, transcriptomic data across fish species and organs are heterogenous and have not been integrated with newly sequenced genomes making gene expression quantification and comparative analyses particularly challenging. Thus, resources integrating genomic and transcriptomic data across fish species and organs are still lacking. Here, we present FEVER, a web-based resource allowing evolutionary transcriptomics across species and tissues. First, based on query genes FEVER reconstructs gene trees providing orthologous and paralogous relationships as well as their evolutionary dynamics across 13 species covering the major fish lineages, and 4 model species as evolutionary outgroups. Second, it provides unbiased gene expression across 11 tissues using up-to-date fish genomes. Finally, genomic and transcriptomic data are combined together allowing the exploration of gene expression evolution following speciation and duplication events. FEVER is freely accessible at https://fever.sk8.inrae.fr/.

evolutionary biology↗

bioRxiv2022

Reconstructing the ancestral vertebrate brain using a lamprey neural cell type atlas

The vertebrate brain emerged more than [~]500 million years ago in common evolutionary ancestors. To systematically trace its cellular and molecular origins, we established a spatially resolved cell type atlas of the entire brain of the sea lamprey - a jawless species whose phylogenetic position affords the reconstruction of ancestral vertebrate traits - based on extensive single-cell RNA-seq and in situ sequencing data. Comparisons of this atlas to neural data from the mouse and other jawed vertebrates unveiled various shared features that enabled the reconstruction of the core cell type composition, tissue structures, and gene expression programs of the ancestral brain. However, our analyses also revealed key tissues and cell types that arose later in evolution. For example, the ancestral vertebrate brain was likely devoid of cerebellar cell types and oligodendrocytes (myelinating cells); our data suggest that the latter emerged from astrocyte-like evolutionary precursors on the jawed vertebrate lineage. Our work illuminates the cellular and molecular architecture of the ancestral vertebrate brain and provides a foundation for exploring its diversification during evolution.

evolutionary biology↗