Cartilaginous fishes offer unique insights into the evolution of the nuclear receptor gene repertoire in gnathostomes

Elza Fonseca, Andre M. Machado, Nair Vilas-Arrondo, Andre Gomes-dos-Santos, Ana Verissimo, Pedro Esteves, Tereza Almeida, Goncalo Themudo, Raquel Ruivo, Montse Perez, Rute da Fonseca, Miguel M. Santos, Elsa Froufe, Esther Roman-Marcote, Byrappa Venkatesh, L. Filipe C. Castro

Research output: Contribution to journalJournal articleResearchpeer-review

16 Citations (Scopus)

Abstract

Nuclear receptors (NRs) are key transcription factors that originated in the common ancestor of metazoans. The vast majority of NRs are triggered by binding to either endogenous (e.g. retinoic acid) or exogenous (e.g. xenobiotics) ligands, and their evolution and expansion is tightly linked to the function of endocrine systems. Importantly, they represent classic targets of physiological exploitation by endocrine disrupting chemicals. The NR gene repertoire in different lineages has been shaped by gene loss, duplication and mutation, denoting a dynamic evolutionary route. As the earliest diverging class of gnathostomes (jawed vertebrates), cartilaginous fishes offer an exceptional opportunity to address the early diversification of NR gene families and the evolution of the endocrine system in jawed vertebrates. Here we provide an exhaustive analysis into the NR gene composition in five elasmobranch (sharks and rays) and two holocephalan (chimaeras) species. For this purpose, we generated also a low coverage draft genome assembly of the chimaera small-eyed rabbitfish, Hydrolagus affinis. We show that cartilaginous fish retain an archetypal NR gene repertoire, similar to that of mammals and coincident with the two rounds of whole genome duplication that occurred in the gnathostome ancestor. Furthermore, novel gene members of the non-canonical NR0B receptors were found in the genomes of this lineage. Our findings provide an essential view into the early diversification of NRs in gnathostomes, paving the way for functional studies.

Original languageEnglish
Article number113527
JournalGeneral and Comparative Endocrinology
Volume295
Number of pages10
ISSN0016-6480
DOIs
Publication statusPublished - 2020

Keywords

  • Nuclear receptors
  • Genome
  • Gene loss
  • Gene duplication
  • HORMONE-RECEPTORS
  • GENOME
  • CHONDRICHTHYES
  • TRANSCRIPTION
  • EXPLOITATION
  • SPECIFICITY
  • AMPHIOXUS
  • QUALITY
  • SHARK
  • RXR

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