title: High-altitude respiration of birds. The primary structures of the alpha D-chains of the Bar-headed Goose (Anser indicus), the Greylag Goose(Anser anser) and the Canada Goose (Branta canadensis).
abstract: The primary structures of the alpha D-chains of the minor component Hb D of Anser indicus, Anser anser and Branta canadensis are presented. Following chain separation by RP-HPLC, the amino-acid sequences were established by automatic Edman degradation of the globin chains and the tryptic peptides. The three chains show a high degree of homology. For the high altitude respiration the alpha 1 beta 1 interface at position alpha 119 is important. For the Bar-headed Goose a mechanism for high altitude respiration involving both Hb A having alanine at position 119 and Hb D having proline at that position is suggested. Furthermore, a possible genetical development of the avian alpha D-gene expression based on a new B alpha-box mutation in the three geese and an unusual 5' splice junction (GT/GC-transition) in the duck gene is discussed. We consider the possibility that the alpha D-gene is an intermediate between a functional gene, reduced in its expression, and a pseudogene.
mesh_terms: D000531:Altitude; D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004912:Erythrocytes / Q000166:cytology; D005777:Geese / Q000097:blood*; D006455:Hemoglobins, Abnormal / Q000032:analysis*; D012119:Respiration
chemical_list: D006455:Hemoglobins, Abnormal; C032001:hemoglobin D