Embryonic chicken hemoglobins. Studies on the oxygen equilibrium of two pure components

Cirotto, Carlo; Geraci, Giuseppe

doi:10.1016/0300-9629(75)90430-2

Cited by 22 publications

(8 citation statements)

References 13 publications

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“…6). Further substantiating this hypothesis is the observation that a serine occurs at this homoglous position in the aD subunit of the HbD (minor) isoform in chicken and geese (Knapp et al 1999;McCracken, KG, unpublished data); serine, like threonine, also possesses a hydroxyl group, and the HbD isoform exhibits higher oxygen affinity and cooperativity than the HbA major isoform (Cirotto & Geraci 1975;Baumann et al 1984;Knapp et al 1999). Tamburrini et al (2000) suggested that the second phosphate binding site contributes to controlled release of oxygen under conditions of hypoxic stress.…”

Section: Discussionmentioning

confidence: 92%

Parallel evolution in the major haemoglobin genes of eight species of Andean waterfowl

et al. 2009

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Theory predicts that parallel evolution should be common when the number of beneficial mutations is limited by selective constraints on protein structure. However, confirmation is scarce in natural populations. Here we studied the major haemoglobin genes of eight Andean duck lineages and compared them to 115 other waterfowl species, including the bar-headed goose (Anser indicus) and Abyssinian blue-winged goose (Cyanochen cyanopterus), two additional species living at high altitude. One to five amino acid replacements were significantly overrepresented or derived in each highland population, and parallel substitutions were more common than in simulated sequences evolved under a neutral model. Two substitutions evolved in parallel in the alpha A subunit of two (Ala-alpha 8) and five (Thr-alpha 77) taxa, and five identical beta A subunit substitutions were observed in two (Ser-beta 4, Glu-beta 94, Met-beta 133) or three (Ser-beta 13, Ser-beta 116) taxa. Substitutions at adjacent sites within the same functional protein region were also observed. Five such replacements were in exterior, solvent-accessible positions on the A helix and AB corner of the alpha A subunit. Five others were in close proximity to inositolpentaphosphate binding sites, and two pairs of independent replacements occurred at two different alpha(1)beta(1) intersubunit contacts. More than half of the substitutions in highland lineages resulted in the acquisition of serine or threonine (18 gains vs. 2 losses), both of which possess a hydroxyl group that can hydrogen bond to a variety of polar substrates. The patterns of parallel evolution observed in these waterfowl suggest that adaptation to high-altitude hypoxia has resulted from selection on unique but overlapping sets of one to five amino acid substitutions in each lineage.

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Section: Discussionmentioning

confidence: 92%

Parallel evolution in the major haemoglobin genes of eight species of Andean waterfowl

et al. 2009

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“…It is also important to identify the molecular mechanisms responsible for differences between the HbA and HbD isoforms in their intrinsic O 2 affinity, allosteric regulation, and oxygen-linked polymerization (Cirotto and Geraci, 1975;Baumann et al, 1984;Riggs, 1998;Knapp et al, 1999;Rana et al, 2008). HbD has been shown to have higher O 2 affinity than HbA, and the ratio of these two isoforms in avian red blood cells may play an important role in modulating blood-O 2 affinity Weber et al, 1988).…”

Section: Resultsmentioning

confidence: 99%

Phylogenetic and structural analysis of the HbA (αA/βA) and HbD (αD/βA) hemoglobin genes in two high-altitude waterfowl from the Himalayas and the Andes: Bar-headed goose (Anser indicus) and Andean goose (Chloephaga melanoptera)

McCracken

Barger

Sorenson

2010

Molecular Phylogenetics and Evolution

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“…We found elevated aA subunit heterozygosity in three out of four taxa with amino acid replacements on both subunits. The major (aA 1 bA 1 /aA 2 bA 2 ) and minor (aD 1 bA 1 /aD 2 bA 2 ) hemoglobin isoforms of birds possess identical bA subunits but differ in their oxygen-binding properties because they possess different a subunits (Cirotto and Geraci 1975;Baumann et al 1984;Riggs 1998;Knapp et al 1999). The HbD isoform has higher oxygen affinity and cooperativity than HbA (Hoffman and Storz 2007;Bulgarella et al 2009).…”

Section: Why Did Elevated Heterozygosity Occur Onmentioning

confidence: 99%

Signatures of High‐Altitude Adaptation in the Major Hemoglobin of Five Species of Andean Dabbling Ducks

McCracken

Barger

Bulgarella

et al. 2009

The American Naturalist

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Hypoxia is one of the most important factors affecting survival at high altitude, and the major hemoglobin protein is a likely target of selection. We compared population genetic structure in the alphaA and betaA hemoglobin subunits (HBA2 and HBB) of five paired lowland and highland populations of Andean dabbling ducks to unlinked reference loci. In the hemoglobin genes, parallel amino acid replacements were overrepresented in highland lineages, and one to five derived substitutions occurred at external solvent-accessible positions on the alpha and beta subunits, at alpha(1)beta(1) intersubunit contacts, or in close proximity to inositolpentaphosphate (IPP) binding sites. Coalescent analyses incorporating the stochasticity of drift and mutation indicated that hemoglobin alleles were less likely to be transferred between highland and lowland populations than unlinked alleles at five other loci. Amino acid replacements that were overrepresented in the highlands were rarely found within lowland populations, suggesting that alleles segregating at high frequency in the highlands may be maladaptive in the lowlands and vice versa. Most highland populations are probably nonmigratory and locally adapted to the Altiplano, but gene flow for several species may be sufficiently high to retard divergence at unlinked loci. Heterozygosity was elevated in the alphaA or betaA subunits of highland populations exhibiting high gene flow between the southern lowlands and the highlands and in highland species that disperse seasonally downslope to midelevation environments from the central Andean plateau. However, elevated heterozygosity occurred more frequently in the alphaA subunit but not simultaneously in both subunits, suggesting that selection may be more constrained by epistasis in the betaA subunit. Concordant patterns among multiple species with different evolutionary histories and depths of historical divergence and gene flow suggest that the major hemoglobin genes of these five dabbling duck species have evolved adaptively in response to high-altitude hypoxia in the Andes.

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Embryonic chicken hemoglobins. Studies on the oxygen equilibrium of two pure components

Cited by 22 publications

References 13 publications

Parallel evolution in the major haemoglobin genes of eight species of Andean waterfowl

Parallel evolution in the major haemoglobin genes of eight species of Andean waterfowl

Phylogenetic and structural analysis of the HbA (αA/βA) and HbD (αD/βA) hemoglobin genes in two high-altitude waterfowl from the Himalayas and the Andes: Bar-headed goose (Anser indicus) and Andean goose (Chloephaga melanoptera)

Signatures of High‐Altitude Adaptation in the Major Hemoglobin of Five Species of Andean Dabbling Ducks

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