Can GC content at third-codon positions be used as a proxy for isochore composition?
Elhaik, Eran LU
; Landan, Giddy
and Graur, Dan
(2009)
In Molecular biology and evolution
26(8).
p.1829-1833
- Abstract
The isochore theory depicts the genomes of warm-blooded vertebrates as a mosaic of long genomic regions that are characterized by relatively homogeneous GC content. In the absence of genomic data, the GC content at third-codon positions of protein-coding genes (GC3) was commonly used as a proxy for the GC content of isochores. Oddly, in the postgenomic era, GC3 is still sometimes used as a proxy for the GC composition of isochores. Here, we use genic and genomic sequences from human, chimpanzee, cow, mouse, rat, chicken, and zebrafish to show that GC3 only explains a very small proportion of the variation in GC content of long genomic sequences flanking the genes (GCf), and what little correlation there is between GC3 and GCf was found... (More)
The isochore theory depicts the genomes of warm-blooded vertebrates as a mosaic of long genomic regions that are characterized by relatively homogeneous GC content. In the absence of genomic data, the GC content at third-codon positions of protein-coding genes (GC3) was commonly used as a proxy for the GC content of isochores. Oddly, in the postgenomic era, GC3 is still sometimes used as a proxy for the GC composition of isochores. Here, we use genic and genomic sequences from human, chimpanzee, cow, mouse, rat, chicken, and zebrafish to show that GC3 only explains a very small proportion of the variation in GC content of long genomic sequences flanking the genes (GCf), and what little correlation there is between GC3 and GCf was found to decay rapidly with distance from the gene. The coefficient of variation of GC3 was found to be much larger than that of GCf and, therefore, GC3 and GCf values are not comparable with each other. Comparisons of orthologous gene pairs from 1) human and chimpanzee and 2) mouse and rat show strong correlations between their GC3 values, but very weak correlations between their GCf values. We conclude that the GC content of third-codon position cannot be used as stand-in for isochoric composition.
(Less)
- author
- Elhaik, Eran
LU
; Landan, Giddy
and Graur, Dan
- publishing date
- 2009-08
- type
- Contribution to journal
- publication status
- published
- keywords
- Animals, Base Composition, Codon/genetics, Genome, Genome, Human, Humans, Isochores/genetics, Proteins/genetics
- in
- Molecular biology and evolution
- volume
- 26
- issue
- 8
- pages
- 1829 - 1833
- publisher
- Oxford University Press
- external identifiers
-
- pmid:19443854
- scopus:67749124224
- ISSN
- 0737-4038
- DOI
- 10.1093/molbev/msp100
- language
- English
- LU publication?
- no
- id
- cbd9b255-1287-4429-9198-a3116872892c
- date added to LUP
- 2019-11-10 16:50:53
- date last changed
- 2024-06-12 04:25:48
@article{cbd9b255-1287-4429-9198-a3116872892c,
abstract = {{<p>The isochore theory depicts the genomes of warm-blooded vertebrates as a mosaic of long genomic regions that are characterized by relatively homogeneous GC content. In the absence of genomic data, the GC content at third-codon positions of protein-coding genes (GC3) was commonly used as a proxy for the GC content of isochores. Oddly, in the postgenomic era, GC3 is still sometimes used as a proxy for the GC composition of isochores. Here, we use genic and genomic sequences from human, chimpanzee, cow, mouse, rat, chicken, and zebrafish to show that GC3 only explains a very small proportion of the variation in GC content of long genomic sequences flanking the genes (GCf), and what little correlation there is between GC3 and GCf was found to decay rapidly with distance from the gene. The coefficient of variation of GC3 was found to be much larger than that of GCf and, therefore, GC3 and GCf values are not comparable with each other. Comparisons of orthologous gene pairs from 1) human and chimpanzee and 2) mouse and rat show strong correlations between their GC3 values, but very weak correlations between their GCf values. We conclude that the GC content of third-codon position cannot be used as stand-in for isochoric composition.</p>}},
author = {{Elhaik, Eran and Landan, Giddy and Graur, Dan}},
issn = {{0737-4038}},
keywords = {{Animals; Base Composition; Codon/genetics; Genome; Genome, Human; Humans; Isochores/genetics; Proteins/genetics}},
language = {{eng}},
number = {{8}},
pages = {{1829--1833}},
publisher = {{Oxford University Press}},
series = {{Molecular biology and evolution}},
title = {{Can GC content at third-codon positions be used as a proxy for isochore composition?}},
url = {{http://dx.doi.org/10.1093/molbev/msp100}},
doi = {{10.1093/molbev/msp100}},
volume = {{26}},
year = {{2009}},
}