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Cytochrome b nucleotide sequence variation among the Atlantic Alcidae
V L Friesen1, W A Montevecchi, W S Davidson
1Department of Biology, Memorial University of Newfoundland, St. John's, Canada.
Hereditas
|January 1, 1993
Summary
Atlantic alcid DNA analysis reveals base composition biases at silent sites, likely due to replication errors and selection. This provides insights into avian evolutionary genetics.
Area of Science:
- Molecular Evolution
- Avian Genetics
- Bioinformatics
Background:
- Cytochrome b gene sequences are crucial for understanding avian phylogeny.
- Silent nucleotide sites can reveal evolutionary pressures and biases.
- Atlantic alcids (family Alcidae) exhibit unique evolutionary histories.
Purpose of the Study:
- To analyze nucleotide sequence variation in cytochrome b across six Atlantic alcid species and a gull.
- To investigate base composition biases at silent sites within the coding strand.
- To infer phylogenetic relationships and evolutionary mechanisms within Atlantic alcids.
Main Methods:
- DNA extraction and sequencing of cytochrome b gene.
- Phylogenetic analysis using nucleotide sequence data.
- Statistical analysis of base composition and substitution patterns.
Main Results:
- An excess of adenine (A) and cytosine (C) and a deficit of guanine (G) were observed at silent sites.
- Phylogenetic analyses consistently grouped common guillemot (Uria aalge) and Brünnich's guillemot (U. lomvia).
- Substitution analysis indicated a higher likelihood of cytosine incorporation over guanine, suggesting a strand bias in replication errors.
Conclusions:
- Base composition imbalances in Atlantic alcids may stem from replication errors influenced by selection on RNA secondary structure or codon-anticodon interactions.
- Phylogenetic relationships suggest the puffin (Fratercula arctica) is an outlier among the studied alcids.
- The findings contribute to understanding molecular evolution and phylogenetic divergence in seabirds.