Dataset Information

An ancient genomic regulatory block conserved across bilaterians and its dismantling in tetrapods by retrogene replacement.

ABSTRACT: Developmental genes are regulated by complex, distantly located cis-regulatory modules (CRMs), often forming genomic regulatory blocks (GRBs) that are conserved among vertebrates and among insects. We have investigated GRBs associated with Iroquois homeobox genes in 39 metazoans. Despite 600 million years of independent evolution, Iroquois genes are linked to ankyrin-repeat-containing Sowah genes in nearly all studied bilaterians. We show that Iroquois-specific CRMs populate the Sowah locus, suggesting that regulatory constraints underlie the maintenance of the Iroquois-Sowah syntenic block. Surprisingly, tetrapod Sowah orthologs are intronless and not associated with Iroquois; however, teleost and elephant shark data demonstrate that this is a derived feature, and that many Iroquois-CRMs were ancestrally located within Sowah introns. Retroposition, gene, and genome duplication have allowed selective elimination of Sowah exons from the Iroquois regulatory landscape while keeping associated CRMs, resulting in large associated gene deserts. These results highlight the importance of CRMs in imposing constraints to genome architecture, even across large phylogenetic distances, and of gene duplication-mediated genetic redundancy to disentangle these constraints, increasing genomic plasticity.

SUBMITTER: Maeso I

PROVIDER: S-EPMC3317147 | biostudies-literature | 2012 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

An ancient genomic regulatory block conserved across bilaterians and its dismantling in tetrapods by retrogene replacement.

Maeso Ignacio I Irimia Manuel M Tena Juan J JJ González-Pérez Esther E Tran David D Ravi Vydianathan V Venkatesh Byrappa B Campuzano Sonsoles S Gómez-Skarmeta José Luis JL Garcia-Fernàndez Jordi J

Genome research 20120110 4

Developmental genes are regulated by complex, distantly located cis-regulatory modules (CRMs), often forming genomic regulatory blocks (GRBs) that are conserved among vertebrates and among insects. We have investigated GRBs associated with Iroquois homeobox genes in 39 metazoans. Despite 600 million years of independent evolution, Iroquois genes are linked to ankyrin-repeat-containing Sowah genes in nearly all studied bilaterians. We show that Iroquois-specific CRMs populate the Sowah locus, sug ...[more]

PMID: 22234889

Similar Datasets

Project description:BACKGROUND:Norepinephrine/noradrenaline is a neurotransmitter implicated in arousal and other aspects of vertebrate behavior and physiology. In invertebrates, adrenergic signaling is considered absent and analogous functions are performed by the biogenic amines octopamine and its precursor tyramine. These chemically similar transmitters signal by related families of G-protein-coupled receptors in vertebrates and invertebrates, suggesting that octopamine/tyramine are the invertebrate equivalents of vertebrate norepinephrine. However, the evolutionary relationships and origin of these transmitter systems remain unclear. RESULTS:Using phylogenetic analysis and receptor pharmacology, here we have established that norepinephrine, octopamine, and tyramine receptors coexist in some marine invertebrates. In the protostomes Platynereis dumerilii (an annelid) and Priapulus caudatus (a priapulid), we have identified and pharmacologically characterized adrenergic ?1 and ?2 receptors that coexist with octopamine ?, octopamine ?, tyramine type 1, and tyramine type 2 receptors. These receptors represent the first examples of adrenergic receptors in protostomes. In the deuterostome Saccoglossus kowalevskii (a hemichordate), we have identified and characterized octopamine ?, octopamine ?, tyramine type 1, and tyramine type 2 receptors, representing the first examples of these receptors in deuterostomes. S. kowalevskii also has adrenergic ?1 and ?2 receptors, indicating that all three signaling systems coexist in this animal. In phylogenetic analysis, we have also identified adrenergic and tyramine receptor orthologs in xenacoelomorphs. CONCLUSIONS:Our results clarify the history of monoamine signaling in bilaterians. Given that all six receptor families (two each for octopamine, tyramine, and norepinephrine) can be found in representatives of the two major clades of Bilateria, the protostomes and the deuterostomes, all six receptors must have coexisted in the last common ancestor of the protostomes and deuterostomes. Adrenergic receptors were lost from most insects and nematodes, and tyramine and octopamine receptors were lost from most deuterostomes. This complex scenario of differential losses cautions that octopamine signaling in protostomes is not a good model for adrenergic signaling in deuterostomes, and that studies of marine animals where all three transmitter systems coexist will be needed for a better understanding of the origin and ancestral functions of these transmitters.

Dataset Information

An ancient genomic regulatory block conserved across bilaterians and its dismantling in tetrapods by retrogene replacement.

Publications

An ancient genomic regulatory block conserved across bilaterians and its dismantling in tetrapods by retrogene replacement.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets