The retinoic acid machinery in invertebrates: Ancestral elements and vertebrate innovations

  title={The retinoic acid machinery in invertebrates: Ancestral elements and vertebrate innovations},
  author={Ricard Albalat},
  journal={Molecular and Cellular Endocrinology},
  • R. Albalat
  • Published 10 December 2009
  • Biology
  • Molecular and Cellular Endocrinology
Expression of a retinoic acid receptor (RAR)-like protein in the embryonic and adult nervous system of a protostome species.
Puttingative disruption of retinoid signaling in Lymnaea embryos using vertebrate RAR antagonists resulted in abnormal eye and shell development and in some instances completely halted development, resembling the effects of all-trans retinoic acid.
Evolution of Retinoid and Steroid Signaling: Vertebrate Diversification from an Amphioxus Perspective
This detailed characterization of genes implicated in retinoid and steroid signaling in amphioxus allows us to reconstruct an outline of these pathways in the ancestral chordate but also to discuss functional innovations inretinoid homeostasis and steroid-dependent regulation in both cephalochordate and vertebrate evolution.
An Orthologue of the Retinoic Acid Receptor (RAR) Is Present in the Ecdysozoa Phylum Priapulida
It is shown, by means of phylogenetics and functional assays, that an orthologue of the nuclear receptor retinoic acid receptor (RAR) subfamily, a central mediator of RA signalling is present in Ecdysozoa, contrary to previous perception.
Machinery and Developmental Role of Retinoic Acid Signaling in Echinoderms
An overview of RA machinery in echinoderms is provided, which identifies its signaling components, and its developmental role is discussed.
Pharmacological evidence for the role of RAR in axon guidance and embryonic development of a protostome species
Pharmacological data support a possible physiological role for the RAR in axon guidance and embryonic development of an invertebrate protostome species.
Retinoic Acid Signaling in Vertebrate Hindbrain Segmentation: Evolution and Diversification
This review investigates how the RA signaling machinery has evolved and diversified and discusses its connection to the hindbrain GRN in relation to diversity, and describes the value of using lamprey as a model for the early-diverged jawless vertebrate group to investigate the elaboration of A-P patterning mechanisms in the vertebrate lineage.
Retinoid level dynamics during gonad recycling in the limpet Patella vulgata.
Effect of retinoids on Post2 Нох gene expression in nereid polychaetes
Under the influence of all-trans-retinal the anterior expression boundary of Post2 Нох gene shifted towards the anterior end both in intact and in regenerating worms of both species, indicating the existence of a relationship between RA signalling and Hox genes in Protostomia.


Is retinoic acid genetic machinery a chordate innovation?
A new hypothesis is proposed in which lineage‐specific duplication and loss of RA machinery genes could be related to the morphological radiation of deuterostomes, in which this new evolutionary viewpoint argues against the hypothesis that the acquisition of gene families underlying RA metabolism and signaling was a key event for the origin of chordates.
Acquisition of Retinoic Acid Signaling Pathway and Innovation of the Chordate Body Plan
Results suggest that the RA signaling cascade, with various regulators and modifiers, had been already well established in the common chordate ancestor and may also have played a part in producing diversity within the chordate groups.
Retinoic acid signaling and the evolution of chordates
To fully understand the evolutionary history of the RA pathway, future research should focus on identification and study of components of theRA signaling cascade in non-chordate deuterostomes and other invertebrates, such as insects, mollusks and cnidarians.
The search for non-chordate retinoic acid signaling: lessons from chordates.
It is concluded that signaling by RA is more likely an ancestral feature of bilaterians than a chordate innovation, and recent advances in the understanding of carotene (pro-Vitamin A) metabolism and of the identification of potential RARs and members of the NR1 family in echinoderms and lophotrochozoan trematodes, respectively.
Retinoic acid signaling in development: Tissue‐specific functions and evolutionary origins
It is suggested that RA signaling might have originated earlier in metazoan evolution than previously thought, and a scenario for the evolution of RA functions during development is proposed, which highlights functional gains and lineage‐specific losses during meetazoan diversification.
Evolutionary genomics of nuclear receptors: from twenty-five ancestral genes to derived endocrine systems.
Notably, differential gene loss played an important role in the evolution of different nuclear receptor sets in bilaterian lineages and was also shaped by periods of gene duplication in vertebrates, as well as a lineage-specific duplication burst in nematodes.
Retinoic acid X receptor in the diploblast, Tripedalia cystophora.
It is shown by cDNA and gene cloning that a Cnidarian, Tripedalia cystophora, possesses a retinoid receptor (jRXR) with remarkable homology to vertebrate retinoic acid X receptors (RXRs), suggesting that RXR is an early component of the regulatory mechanisms of metazoa.
Retinoic acid, HOX genes and the anterior‐posterior axis in chordates
The role of retinoic acid in anterior-posterior axis specification may be a chordate innovation, perhaps linked to the evolution of another chordate character, the dorsal neural tube.