Nom du corpus

Corpus Systématique Animale

Titre du document

The compositional patterns of the avian genomes and their evolutionary implications

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Springer (journals)
Langue(s) du document
Type de document
Mots-clés d'auteur
  • Isochores
  • DNA
  • Coding sequences
  • Birds
  • Mammals
  • Evolution
Nom du fichier dans la ressource
Mammiferes_v2b_00925, Oiseaux_v2b_00984, Reptiles_v2b_00278
  • Farida Kadi 1
  • Dominique Mouchiroud 2
  • Georgette Sabeur 3
  • Giorgio Bernardi 1
  • 1) Laboratoire de Génétique Moléculaire, Institut Jacques Monod, 2 Place Jussieu, 75005, Paris, France
  • 2) Laboratoire de Biométrie, Génétique et Biologíe des Populations, Université Claude Bernard, U.R.A. 243, 69600, Villeurbanne, France
  • 3) Faculté de Médecine Nord, Boulevard Pierre Dramard, 13326, Marseille Cedex, France

The compositional distributions of large (main-band) DNA fragments from eight birds belonging to eight different orders (including both paleognathous and neognathous species) are very broad and extremely close to each other. These findings, which are paralleled by the compositional similarity of homologous coding sequences and their codon positions, support the idea that birds are a monophyletic group. The compositional distribution of third-codon positions of genes from chicken, the only avian species for which a relatively large number of coding sequences is known, is very broad and bimodal, the minor GC-richer peak reaching 100% GC. The very high compositional heterogeneity of avian genomes is accompanied (as in the case of mammalian genomes) by a very high speciation rate compared to cold-blooded vertebrates which are characterized by genomes that are much less heterogeneous. The higher GC levels attained by avian compared to mammalian genomes might be correlated with the higher body temperature (41–43°C) of birds compared to mammals (37°C). A comparison of GC levels of coding sequences and codon positions from man and chicken revealed very close average GC levels and standard deviations. Homologous coding sequences and codon positions from man and chicken showed a surprisingly high degree of compositional similarity which was, however, higher for GC-poor than for GC-rich sequences. This indicates that GC-poor isochores of warm-blooded vertebrates reflect the composition of the isochores of the genome of the common reptilian ancestor of mammals and birds, which underwent only a small compositional change at the transition from cold- to warm-blooded vertebrates. In contrast, the GC-rich isochores of birds and mammals are the result of large compositional changes at the same evolutionary transition, where were in part different in the two classes of warm-blooded vertebrates.

Catégories Science-Metrix
  • 1 - natural sciences
  • 2 - biology
  • 3 - evolutionary biology
Catégories INIST
  • 1 - sciences appliquees, technologies et medecines
  • 2 - sciences biologiques et medicales
  • 3 - sciences biologiques fondamentales et appliquees. psychologie
Catégories Scopus
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Genetics
  • 1 - Life Sciences ; 2 - Biochemistry, Genetics and Molecular Biology ; 3 - Molecular Biology
  • 1 - Life Sciences ; 2 - Agricultural and Biological Sciences ; 3 - Ecology, Evolution, Behavior and Systematics
Catégories WoS
  • 1 - science ; 2 - genetics & heredity
  • 1 - science ; 2 - evolutionary biology
  • 1 - science ; 2 - biochemistry & molecular biology
Identifiant ISTEX

Journal of Molecular Evolution

Année de publication
Présence de XML structuré
Version PDF
Score qualité du texte
  • Mammiferes
  • Oiseaux
  • Reptiles
Type de publication
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