Genetic diversity of coastal bottlenose dolphins revealed by structurally and functionally diverse hemoglobins.
Genetic diversity of coastal bottlenose dolphins revealed by structurally and functionally diverse hemoglobins.
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结构和功能多样化的血红蛋白揭示了沿海宽吻海豚的遗传多样性。
DOI：
10.1016/j.gene.2007.02.050
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发表时间：
2007
期刊：
影响因子：
3.5
通讯作者：
Bonaventura,Celia
中科院分区：
文献类型：
--
作者：
Remington,Nicole;Stevens,RobertD;Wells,RandallS;Holn,Aleta;Dhungana,Suraj;Taboy,CelineH;Crumbliss,AlvinL;Henkens,Robert;Bonaventura,Celia
对海洋哺乳动物呼吸蛋白的结构-功能关系的研究发现，沿海宽吻海豚的血红蛋白(Hb)的数量和类型存在意外的变化。我们采集了自由活动的沿海宽吻海豚的血液样本，作为捕获-释放研究的一个组成部分。我们发现，宽吻海豚血液的氧结合功能在效应器饱和和不饱和水平之间保持平衡，使得氧转移功能随着运动而发生变化。在没有变构效应的情况下，分离的宽吻海豚Hb表现出比成人Hb更高的pH敏感性(玻尔效应)和略低的氧亲和力。这些特性可能是一种适应性修改，在氧气紧张和效应器水平较低的潜水期间增强氧气输送。单个海豚的HBS表现出相似的氧亲和力、对效应物的反应以及在氧结合中血红素-血红素相互作用的表达，但它们的氧化还原电位和自氧化速率不同。单个海豚HBs的这些功能变异所表明的异质性是由于它们的α和β珠蛋白链的分子量和数量的不同而产生的。尽管沿海宽吻海豚预计只有一种类型的HB，但观察到的群体差异揭示了相当大的遗传多样性。部分个体存在多种Hb类型，同一群落内个体间Hb类型存在差异。
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 α and β 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.