Search bioRxiv⌕ Search

Biology subjects

Castro, L. F.

Publications and source records attributed to Castro, L. F..

4 recordsLinked to original sources

A multi-tissue de novo transcriptome assembly and relative gene expression of the vulnerable freshwater salmonid Thymallus ligericus

Freshwater ecosystems are among the most endangered worldwide. While numerous taxa are on the verge of extinction as a result of global changes and direct or indirect anthropogenic activity, genomic and transcriptomic resources are a key tool to comprehend species adaptability and serve as the foundation for conservation initiatives. The Loire grayling, Thymallus ligericus, is a freshwater European salmonid endemic to the upper Loire River basin. It comprises fragmented populations dispersed over a small area and has been identified as a vulnerable species. Here, we provide a multi-tissue de novo transcriptome assembly of T. ligericus. The final assembly, with a contig N50 of 1,221 and Benchmarking Universal Single-Copy Orthologs (BUSCO) scores above 94%, is made accessible, along with structural and functional annotations and relative gene expression of five tissues. This is the first transcriptomic resource for this species, and it will serve as the foundation for future research on a species that is increasingly exposed to environmental stressors.

genomics↗

The dopamine receptor D5 gene shows signs of independent erosion in Toothed and Baleen whales

To compare gene loci considering a phylogenetic framework is a promising approach to uncover the genetic basis of human diseases. Imbalance of dopaminergic systems is suspected to underlie some emerging neurological disorders. The physiological functions of dopamine are transduced via G-protein-coupled receptors, including DRD5 which displays a relatively higher affinity towards dopamine. Importantly, DRD5 knockout mice are hypertense, a condition emerging from an increase in sympathetic tone. We investigated the evolution of DRD5, a high affinity receptor for dopamine, in mammals. Surprisingly, among 124 investigated mammalian genomes, we found that Cetacea lineages (Mysticeti and Odontoceti) have independently lost this gene, as well as the burrowing Chrysochloris asiatica (Cape golden mole). We suggest that DRD5 inactivation parallels hypoxia-induced adaptations, such as peripheral vasoconstriction required for deep-diving in Cetacea, in accordance with the convergent evolution of vasoconstrictor genes in hypoxia-exposed animals. Our findings indicate that Cetacea are natural knockouts for DRD5 and might offer valuable insights into the mechanisms of some forms of vasoconstriction responses and hypertension in humans.

evolutionary biology↗

Expansion, retention and loss in the Acyl-CoA Synthetase \"Bubblegum\" (Acsbg) gene family in vertebrate history

AO_SCPLOWBSTRACTC_SCPLOWFatty acids (FAs) constitute a considerable fraction of all lipid molecules with a fundamental role in numerous physiological processes. In animals, the majority of complex lipid molecules are derived from the transformation of FAs through several biochemical pathways. Yet, for FAs to enroll in these pathways they require an activation step. FA activation is catalyzed by the rate limiting action of Acyl-CoA synthases. Several Acyl-CoA enzyme families have been previously described and classified according to the chain length of FA they process. Here, we address the evolutionary history of the ACSBG gene family which activates, FA with more than 16 carbons. Currently, two different ACSBG gene families, ACSBG1 and ACSBG2, are recognized in vertebrates. We provide evidence that a wider and unequal ACSBG gene repertoire is present in vertebrate lineages. We identify a novel ACSBG-like gene lineage which occurs specifically in amphibians, ray finned fish, coelacanths and chondrichthyes named ACSBG3. Also, we show that the ACSBG2 gene lineage duplicated in the Theria ancestor. Our findings, thus offer a far richer understanding on FA activation in vertebrates and provide key insights into the relevance of comparative and functional analysis to perceive physiological differences, namely those related with lipid metabolic pathways.

genetics↗

A taxonomically-restricted Uric Acid transporter provides insight into antioxidant equilibrium

Nucleobase-Ascorbate Transporter (NAT) family includes ascorbic acid, nucleobases and uric acid transporters, with a broad evolutionary distribution. In vertebrates, four members have been previously recognized, the ascorbate transporters Slc23a1 and Slc3a2, the nucleobase transporter Slc23a4 and an orphan transporter SLC23A3. Here we identify a fifth member of the vertebrate slc23 complement (slc23a5), expressed in neopterygians (gars and teleosts) and amphibians, and clarify the evolutionary relationships between the novel gene and known slc23 genes. Further comparative analysis puts forward uric acid as the preferred substrate for Slc23a5. Gene expression quantification suggests kidney and testis as major expression sites in Xenopus tropicalis (western clawed frog) and Danio rerio (zebrafish). Additional expression in brain was detected in D. rerio, while in the Neoteleostei Oryzias latipes (medaka) slc23a5 expression is restricted to brain. The biological relevance of the retention of an extra transporter in fish and amphibians is examined: with respect to the (1) antioxidant role of uric and ascorbic acid in seminal fluid and brain, (2) the ability to endogenously synthesize ascorbic acid and (3) the morphological adaptations of the male urogenital system.

evolutionary biology↗