Biology subjects

Albalat, R.

Publications and source records attributed to Albalat, R..

4 recordsLinked to original sources

bioRxiv2025

THE EVOLUTIONARY HISTORY OF METALLOTHIONEINS IN HORSESHOE CRABS, SCORPIONS, SPIDERS AND OTHER CHELICERATE SPECIES.

Metallothioneins (MTs) are a heterogenous family of proteins involved in metal homeostasis and detoxification, playing a crucial role in the adaptation of organisms to varying conditions of metal bioavailability across ecosystems. Despite their significance, MT characterization across animal groups remains uneven. While MTs have been extensively studied in vertebrates and gastropods, their presence and function in many arthropods, particularly within the Chelicerata subphylum, remain largely unexplored. Chelicerates, comprising thousands of species of spiders, scorpions and ticks, are a highly diverse group of animals inhabiting a wide range of environments. Identifying and characterizing their MTs is therefore essential for understanding how they manage metal availability of diverse habitats. In this study, we have identified over 400 chelicerate MTs, classifying them into three distinct types -types 1, 2, and 3- each exhibiting significant structural and phylogenetic differences. Our findings have revealed that most chelicerate MTs are bidomain proteins, with notable exceptions of monodomain forms and larger variants. Evolutionary analysis suggests that type 1 MTs represent the ancestral form, while types 2 and 3 likely emerged during the evolution of spiders. These results pave the way of a deeper understanding of the metal homeostasis and detoxification in chelicerates, laying the groundwork for future studies on the origin, evolution and functional diversification of MTs in arthropods and other metazoan lineages.

evolutionary biology↗

bioRxiv2024

Less, but more: new insights from appendicularians on chordate Fgf evolution and the divergence of tunicate lifestyles.

The impact of gene loss on the divergence of taxa and the generation of evolutionary innovations is a fundamental aspect of Evolutionary Biology that remains unclear. Here, using the evolution of the Fibroblast Growth Factors (FGFs) in appendicularians as a case study, we investigate how gene losses have influenced the evolution of chordates, especially the divergence among tunicates. Our work reveals an unprecedented case of massive losses of all Fgf gene subfamilies, except for the Fgf9/16/20 and Fgf11/12/13/14, which in turn suffered two bursts of gene duplications. Phylogenetic inferences and genomic analyses of gene synteny conservation, gene architecture, alternative splicing and protein 3D-structure have allowed us to reconstruct the history of appendicularian Fgf genes in the context of chordate evolution, providing compelling evidence supporting the paracrine secreting functions and the intracellular functions of the Fgf9/16/20 and Fgf11/12/13/14 subfamilies, respectively. Exhaustive analysis of developmental Fgf expression in Oikopleura dioica as a model for appendicularians reveals a paradigmatic case of what could be referred as "less, but more", providing a conceptual evolutionary framework characterized by four associated evolutionary patterns: conservation of ancestral Fgf expression domains; function shuffling between paralogs upon gene loss; innovation of new expression domains after the bursts of Fgf duplications; and the extinction of Fgf functions linked to gene losses. The findings of this work allow us to formulate novel hypotheses about the potential impact of losses and duplications of Fgf genes on the transition from an ancestral ascidian-like biphasic lifestyle to a fully free-living style of appendicularians. These hypotheses include the massive co-option of Fgf genes for the patterning of the oikoblast responsible of the house architecture, and for the development of the tail fin; the recruitment of Fgf11/12/13/14 genes into the evolution of a new mouth, and their role modulating neuronal excitability; the evolutionary innovation of an "anterior tail" FGF signaling mesodermal source upon the loss of retinoic acid signaling; and the potential link between the loss of Fgf7/10/22 and Fgf8/17/18 and the loss of drastic metamorphosis, mesenchymal cells and lack of tail absorption in appendicularians, in contrast to ascidians.

evolutionary biology↗

bioRxiv2024

Developmental toxicity of pre-production plastic pellets affects a large swathe of invertebrate taxa

Microplastics pose risks to marine organisms through ingestion, entanglement, and as carriers of toxic additives and environmental pollutants. Plastic pre-production pellet leachates have been shown to affect the development of sea urchins and, to some extent, mussels. The extent of those developmental effects on other animal phyla remains unknown. Here, we test the toxicity of environmental mixed nurdle samples and new PVC pellets for the embryonic development or asexual reproduction by regeneration of animals from all the major animal superphyla (Lophotrochozoa, Ecdysozoa, Deuterostomia and Cnidaria). Our results show diverse, concentration-dependent impacts in all the species sampled for new pellets, and for molluscs and deuterostomes for environmental samples. Embryo axial formation, cell specification and, specially, morphogenesis seem to be the main processes affected by plastic leachate exposure. Our study serves as a proof of principle for the potentially catastrophic effects that increasing plastic concentrations in the oceans and other ecosystems can have across animal populations from all major animal superphyla.

developmental biology↗

bioRxiv2021

Cardiopharyngeal deconstruction and ancestral tunicate sessility

A key problem in understanding chordate evolution has been the origin of sessility of ascidians, and whether the appendicularian free-living style represents a primitive or derived condition of tunicates. To address this problem, we performed comprehensive developmental and genomic comparative analyses of the cardiopharyngeal gene regulatory network (GRN) between appendicularians and ascidians. Our results reveal that the cardiopharyngeal GRN has suffered a process of evolutionary deconstruction with massive ancestral losses of genes (Mesp, Ets1/2, Gata4/5/6, Mek1/2, Tbx1/10, and RA- and FGF-signaling related genes) and subfunctions (e.g. FoxF, Islet, Ebf, Mrf, Dach and Bmp signaling). These losses have led to the deconstruction of two modules of the cardiopharyngeal GRN that in ascidians are related to early and late multipotent state cells involved in lineage fate determination towards first and secondary heart fields, and siphon muscle. Our results allow us to propose an evolutionary scenario, in which the evolutionary deconstruction of the cardiopharyngeal GRN has had an adaptive impact on the acceleration of the developmental cardiac program, the redesign of the cardiac architecture into an open-wide laminar structure, and the loss of pharyngeal muscle. Our findings, therefore, provide evidence supporting that the ancestral tunicate had a sessile ascidian-like lifestyle, and points to the deconstruction of the cardiopharyngeal GRN in appendicularians as a key event that facilitated the evolution of their pelagic free-living style connected to the innovation of the house.

evolutionary biology↗