Long before Alfred Hitchcock, Charles Darwin, and even John Audubon, man had a passion for studying birds. Now, scientists from the University of Washington have sequenced a region of the house finch genome, providing the largest sequence available from any songbird. As reported in this month's issue of Genome Research, the researchers also present the first description of a bird's "genomic signature" - showing that the bird genome is both similar to and significantly different from mammalian genomes.
The house finch belongs to a group called the Passeriformes, or perching songbirds, which contains over half the living species of birds. Scott Edwards and colleagues focused on genes operating in the finch immune system, sequencing the 32,000 bases around an identified immune response gene (Mhc class II). The researchers found that this region contains several genes but relatively few of the "excess" elements common in mammalian genomes, such as repeats and retroelements. This minimalism agrees with the notion that the metabolic demands of bird-flight favor a compact genome. In addition, they analyzed the "genomic signature" of the finch by determining how often different combinations of bases (e.g., GC or TA) occurred in the sequence. The signature of the finch genome is remarkably similar to mammalian signatures, suggesting that birds and mammals share not only warm bodies and backbones, but basic genome structure as well.
Contact (author):
Scott Edwards
Department of Zoology
University of Washington
Seattle, WA 98195
USA
Email: edwards@zoology.washington.edu
Genome Research