Genetic diversity of coastal bottlenose dolphins revealed by structurally and functionally diverse hemoglobins.

Published

Journal Article

Studies of structure-function relationships in the respiratory proteins of marine mammals revealed unexpected variations in the number and types of hemoglobins (Hbs) present in coastal bottlenose dolphins, Tursiops truncatus. We obtained blood samples from free-ranging coastal bottlenose dolphins as a component of capture-release studies. We found that the oxygen-binding functions of bottlenose dolphin blood are poised between effector-saturated and unsaturated levels, enabling exercise-dependent shifts in oxygen transfer functions. Isolated bottlenose dolphin Hbs showed elevated pH sensitivities (Bohr effects) and appreciably lower oxygen affinities than adult human Hb in the absence of allosteric effectors. These properties may be an adaptive modification that enhances oxygen delivery during diving episodes when oxygen tensions and effector levels are low. The Hbs of individual dolphins showed similar oxygen affinities, responses to effectors, and expression of heme-heme interaction in oxygen binding, but differed in their redox potentials and rates of autoxidation. The heterogeneity suggested by these functional variations in Hbs of individual dolphins was born out by variations in the molecular weights and numbers of their alpha and beta globin chains. Although coastal bottlenose dolphins were expected to have a single type of Hb, the mass differences observed revealed considerable genetic diversity. There were multiple Hb forms in some individuals and differences in Hb patterns among individuals within the same community.

Full Text

Duke Authors

Cited Authors

  • Remington, N; Stevens, RD; Wells, RS; Holn, A; Dhungana, S; Taboy, CH; Crumbliss, AL; Henkens, R; Bonaventura, C

Published Date

  • August 15, 2007

Published In

Volume / Issue

  • 398 / 1-2

Start / End Page

  • 123 - 131

PubMed ID

  • 17604574

Pubmed Central ID

  • 17604574

International Standard Serial Number (ISSN)

  • 0378-1119

Digital Object Identifier (DOI)

  • 10.1016/j.gene.2007.02.050

Language

  • eng

Conference Location

  • Netherlands