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Our junk DNA hard at work: “Pseudo-pseudo genes” division


From Prieto-Godino LL, Rytz R, Bargeton B, Abuin L, Arguello JR, Peraro MD, Benton R, at Nature:

Olfactory receptor pseudo-pseudogenes,² Nature 2016 Oct 24 doi:10.1038/nature19824. PMID:27776356

Abstract: Pseudogenes are generally considered to be non-functional DNA sequences that arise through nonsense or frame-shift mutations of protein-coding genes. Although certain pseudogene-derived RNAs have regulatory roles, and some pseudogene fragments are translated, no clear functions for pseudogene-derived proteins are known. Olfactory receptor families contain many pseudogenes, which reflect low selection pressures on loci no longer relevant to the fitness of a species. Here we report the characterization of a pseudogene in the chemosensory variant ionotropic glutamate receptor repertoire of Drosophila sechellia, an insect endemic to the Seychelles that feeds almost exclusively on the ripe fruit of Morinda citrifolia. This locus, D. sechellia Ir75a, bears a premature termination codon (PTC) that appears to be fixed in the population. However, D. sechellia Ir75a encodes a functional receptor, owing to efficient translational read-through of the
PTC. Read-through is detected only in neurons and is independent of the type of termination codon, but depends on the sequence downstream of the PTC. Furthermore, although the intact Drosophila melanogaster Ir75a orthologue detects acetic acid-a chemical cue important for locating fermenting food found only at trace levels in Morinda fruit-D. sechellia Ir75a has evolved distinct odour-tuning properties through amino-acid changes in its ligand-binding domain. We identify functional PTC-containing loci within different olfactory receptor repertoires and species, suggesting that such ‘pseudo-pseudogenes’ could represent a widespread phenomenon.


Myth of Junk DNA

See also: Another accidental use for junk DNA

Endogenous retro viruses made us human?

Who else believed in the myth of junk DNA? Jerry Coyne, for example

and The Myth of Junk DNA

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Non-Coding RNA — Open Access Journal
Non-Coding RNA (ISSN 2311-553X) is an international open access journal on non-coding RNA research dealing with elucidating the structure, function and biology of regulatory non-coding RNAs. ncRNA is published quarterly online by MDPI.
http://www.mdpi.com/journal/ncrna About Non-Coding RNA Aims
Non-coding RNA (ISSN 2311-553X) is an open access journal which provides an advanced forum for research studies on non-coding RNAs and their regulatory roles. It publishes primarily original research papers, short reports, communications, snapshots and conference reports. Our aim is to encourage scientists to publish their experimental and theoretical results in as much detail as possible. There is no restriction on the length of the papers. The full experimental details must be provided so that the results can be reproduced. We also encourage the publication of timely reviews and of commentaries on hot topics of interest to the non-coding RNAs community.
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