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A bird's-eye view of chromosomic evolution in the Class Aves

O’Connor, Rebecca E., Kretschmer, Rafael, Romanov, Michael N., Griffin, Darren K. (2024) A bird's-eye view of chromosomic evolution in the Class Aves. Cells, 13 (4). Article Number 310. ISSN 2073-4409. E-ISSN 2073-4409. (doi:10.3390/cells13040310) (KAR id:104902)


Birds (Aves) are the most speciose of terrestrial vertebrates, displaying Class-specific characteristics yet incredible external phenotypic diversity. Critical to agriculture and as model organisms, birds have adapted to many habitats. The only extant examples of dinosaurs, birds emerged ~150 mya and >10% are currently threatened with extinction. This review is a comprehensive overview of avian genome (“chromosomic”) organization research based mostly on chromosome painting and BAC-based studies. We discuss traditional and contemporary tools for reliably generating chromosome-level assemblies and analyzing multiple species at a higher resolution and wider phylogenetic distance than previously possible. These results permit more detailed investigations into inter- and intrachromosomal rearrangements, providing unique insights into evolution and speciation mechanisms. The ‘signature’ avian karyotype likely arose ~250 mya and remained largely unchanged in most groups including extinct dinosaurs. Exceptions include Psittaciformes, Falconiformes, Caprimulgiformes, Cuculiformes, Suliformes, occasional Passeriformes, Ciconiiformes, and Pelecaniformes. The reasons for this remarkable conservation may be the greater diploid chromosome number generating variation (the driver of natural selection) through a greater possible combination of gametes and/or an increase in recombination rate. A deeper understanding of avian genomic structure permits the exploration of fundamental biological questions pertaining to the role of evolutionary breakpoint regions and homologous synteny blocks.

Item Type: Article
DOI/Identification number: 10.3390/cells13040310
Additional information: For the purpose of open access, the author has applied a CC BY public copyright licence to any Author Accepted Manuscript version arising from this submission.
Uncontrolled keywords: avian species; macrochromosome; comparative cytogenetic maps; BACs; chromosome rearrangements; phylogenomics
Subjects: Q Science > QH Natural history > QH324.2 Computational biology
Q Science > QH Natural history > QH426 Genetics
Q Science > QH Natural history > QH581.2 Cell Biology
Q Science > QL Zoology
Divisions: Divisions > Division of Natural Sciences > Centre for Interdisciplinary Studies of Reproduction
Divisions > Division of Natural Sciences > Biosciences
Signature Themes: Food Systems, Natural Resources and Environment
Funders: Biotechnology and Biological Sciences Research Council (
Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (
Depositing User: Mike Romanov
Date Deposited: 07 Feb 2024 13:45 UTC
Last Modified: 16 Feb 2024 14:31 UTC
Resource URI: (The current URI for this page, for reference purposes)

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