uu.seUppsala University Publications
Change search
ReferencesLink to record
Permanent link

Direct link
Molecular evolutionary genomics of birds
Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolution, Genomics and Systematics, Evolutionary Biology. (Molecular evolution)
2007 (English)In: Cytogenetic and Genome Research, ISSN 1424-8581, E-ISSN 1424-859X, Vol. 117, no 1-4, 120-130 p.Article, review/survey (Refereed) Published
Abstract [en]

Insight into the molecular evolution of birds has been offered by the steady accumulation of avian DNA sequence data, recently culminating in the first draft sequence of an avian genome, that of chicken. By studying avian molecular evolution we can learn about adaptations and phenotypic evolution in birds, and also gain an understanding of the similarities and differences between mammalian and avian genomes. In both these lineages, there is pronounced isochore structure with highly variable GC content. However, while mammalian isochores are decaying, they are maintained in the chicken lineage, which is consistent with a biased gene conversion model where the high and variable recombination rate of birds reinforces heterogeneity in GC. In Galliformes, GC is positively correlated with the rate of nucleotide substitution; the mean neutral mutation rate is 0.12-0.15% at each site per million years but this estimate comes with significant local variation in the rate of mutation. Comparative genomics reveals lower dN/dS ratios on micro- compared to macrochromosomes, possibly due to population genetic effects or a non-random distribution of genes with respect to chromosome size. A non-random genomic distribution is shown by genes with sex-biased expression, with male-biased genes over-represented and female-biased genes under-represented on the Z chromosome. A strong effect of selection is evident on the non-recombining W chromosome with high dN/dS ratios and limited polymorphism. Nucleotide diversity in chicken is estimated at 4-5 √ó 10-3 which might be seen as surprisingly high given presumed bottlenecks during domestication, but is lower than that recently observed in several natural populations of other species. Several important aspects of the molecular evolutionary process of birds remain to be understood and it can be anticipated that the upcoming genome sequence of a second bird species, the zebra finch, as well as the integration of data on gene expression, shall further advance our knowledge of avian evolution.

Place, publisher, year, edition, pages
2007. Vol. 117, no 1-4, 120-130 p.
National Category
Biological Sciences
URN: urn:nbn:se:uu:diva-15725DOI: 10.1159/000103172ISI: 000249980800015OAI: oai:DiVA.org:uu-15725DiVA: diva2:43496
Available from: 2008-03-04 Created: 2008-03-04 Last updated: 2011-03-29Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full text

Search in DiVA

By author/editor
Hans, Ellegren
By organisation
Evolutionary Biology
In the same journal
Cytogenetic and Genome Research
Biological Sciences

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 213 hits
ReferencesLink to record
Permanent link

Direct link