Novel, de novo, beta‐globin variant with decreased oxygen affinity ( HBB :c. 317T >A, “ Hemoglobin St. George ”) in a healthy child with low oxygen saturations and anemia

A major challenge in evolutionary biology is to identify the genes underlying adaptation. The oxygen-transporting haemoglobins directly link external conditions with metabolic needs and therefore represent a unique system for studying environmental effects on molecular evolution. We have discovered two haemoglobin polymorphisms in Atlantic cod populations inhabiting varying temperature and oxygen regimes in the North Atlantic. Three-dimensional modelling of the tetrameric haemoglobin structure demonstrated that the two amino acid replacements Met55β 1 Val and Lys62β 1 Ala are located at crucial positions of the α 1 β 1 subunit interface and haem pocket, respectively. The replacements are proposed to affect the oxygen-binding properties by modifying the haemoglobin quaternary structure and electrostatic feature. Intriguingly, the same molecular mechanism for facilitating oxygen binding is found in avian species adapted to high altitudes, illustrating convergent evolution in water- and air-breathing vertebrates to reduction in environmental oxygen availability. Cod populations inhabiting the cold Arctic waters and the low-oxygen Baltic Sea seem well adapted to these conditions by possessing the high oxygen affinity Val55–Ala62 haplotype, while the temperature-insensitive Met55–Lys62 haplotype predominates in the southern populations. The distinct distributions of the functionally different haemoglobin variants indicate that the present biogeography of this ecologically and economically important species might be seriously affected by global warming.

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Long-Term Waterlogging as Factor Contributing to Hypoxia Stress Tolerance Enhancement in Cucumber: Comparative Transcriptome Analysis of Waterlogging Sensitive and Tolerant Accessions

Genes ◽

10.3390/genes12020189 ◽

2021 ◽

Vol 12 (2) ◽

pp. 189

Author(s):

Kinga Kęska ◽

Michał Wojciech Szcześniak ◽

Izabela Makałowska ◽

Małgorzata Czernicka

Keyword(s):

Stress Tolerance ◽

De Novo ◽

Average Length ◽

Marker Genes ◽

Long Term Memory ◽

Low Oxygen ◽

Waterlogging Tolerance ◽

Pre Treatment ◽

Waterlogging Treatment

Waterlogging (WL), excess water in the soil, is a phenomenon often occurring during plant cultivation causing low oxygen levels (hypoxia) in the soil. The aim of this study was to identify candidate genes involved in long-term waterlogging tolerance in cucumber using RNA sequencing. Here, we also determined how waterlogging pre-treatment (priming) influenced long-term memory in WL tolerant (WL-T) and WL sensitive (WL-S) i.e., DH2 and DH4 accessions, respectively. This work uncovered various differentially expressed genes (DEGs) activated in the long-term recovery in both accessions. De novo assembly generated 36,712 transcripts with an average length of 2236 bp. The results revealed that long-term waterlogging had divergent impacts on gene expression in WL-T DH2 and WL-S DH4 cucumber accessions: after 7 days of waterlogging, more DEGs in comparison to control conditions were identified in WL-S DH4 (8927) than in WL-T DH2 (5957). Additionally, 11,619 and 5007 DEGs were identified after a second waterlogging treatment in the WL-S and WL-T accessions, respectively. We identified genes associated with WL in cucumber that were especially related to enhanced glycolysis, adventitious roots development, and amino acid metabolism. qRT-PCR assay for hypoxia marker genes i.e., alcohol dehydrogenase (adh), 1-aminocyclopropane-1-carboxylate oxidase (aco) and long chain acyl-CoA synthetase 6 (lacs6) confirmed differences in response to waterlogging stress between sensitive and tolerant cucumbers and effectiveness of priming to enhance stress tolerance.

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Purification, Crystallization and Preliminary X-Ray Diffraction Studies on Goat (Capra hircus) Hemoglobin - A Low Oxygen Affinity Species

Protein and Peptide Letters ◽

10.2174/092986609787847992 ◽

2009 ◽

Vol 16 (4) ◽

pp. 454-456 ◽

Cited By ~ 1

Author(s):

Ponnuraj Moorthy ◽

Kamariah Neelagandan ◽

Moovarkumudalvan Balasubramanian ◽

Mondikalipudur Ponnuswamy

Keyword(s):

Oxygen Affinity ◽

Capra Hircus ◽

Low Oxygen ◽

X Ray Diffraction ◽

X Ray ◽

Hemoglobin A ◽

Low Oxygen Affinity

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Effect of polyanionic polymers on haemoglobin oxygen-binding properties: application to the synthesis of covalent conjugates with low oxygen affinity

International Journal of Biological Macromolecules ◽

10.1016/0141-8130(87)90006-7 ◽

1987 ◽

Vol 9 (6) ◽

pp. 343-345 ◽

Cited By ~ 9

Author(s):

Danièle Zygmunt ◽

Michèle Léonard ◽

François Bonneaux ◽

Daniel Sacco ◽

Edith Dellacherie

Keyword(s):

Oxygen Affinity ◽

Oxygen Binding ◽

Low Oxygen ◽

Binding Properties ◽

Covalent Conjugates ◽

Low Oxygen Affinity

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Influence of carbon monoxide on hemoglobin-oxygen binding

Journal of Applied Physiology ◽

10.1152/jappl.1976.41.6.893 ◽

1976 ◽

Vol 41 (6) ◽

pp. 893-899 ◽

Cited By ~ 37

Author(s):

M. P. Hlastala ◽

H. P. McKenna ◽

R. L. Franada ◽

J. C. Detter

Keyword(s):

Carbon Monoxide ◽

Oxygen Affinity ◽

Co2 Concentration ◽

Bohr Effect ◽

Oxygen Binding ◽

Dissociation Curve ◽

Low Oxygen ◽

Oxygen Dissociation ◽

Initial Binding ◽

Fixed Acid

The oxygen dissociation curve and Bohr effect were measured in normal whole blood as a function of carboxyhemoglobin concentration [HbCO]. pH was changed by varying CO2 concentration (CO2 Bohr effect) or by addition of isotonic NaOH or HCl at constant PCO2 (fixed acid Bohr effect). As [HbCO] varied through the range of 2, 25, 50, and 75%, P50 was 26.3, 18.0, 11.6, and 6.5 mmHg, respectively. CO2 Bohr effect was highest at low oxygen saturations. This effect did not change as [HbCO] was increased. However, as [HbCO] was increased from 2 to 75%, the fixed acid Bohr factor increased in magnitude from -0.20 to -0.80 at very low oxygen saturations. The effect of molecular CO2 binding (carbamino) on oxygen affinity was eliminated at high [HbCO]. These results are consistent with the initial binding of O2 or CO to thealpha-chain of hemoglobin. The results also suggest that heme-heme interaction is different for oxygen than for carbon monoxide.

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Hemoglobin-Based Artificial Blood: New Polymeric Derivatives of Hemoglobin with Low Oxygen Affinity

The International Journal of Artificial Organs ◽

10.1177/039139889101400107 ◽

1991 ◽

Vol 14 (1) ◽

pp. 28-32 ◽

Cited By ~ 3

Author(s):

E. Dellacherie ◽

C. Vigneron

Keyword(s):

Oxygen Affinity ◽

Low Oxygen ◽

Artificial Blood ◽

Derivatives Of ◽

Low Oxygen Affinity

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Hemoglobin Titusville: a rare low oxygen affinity hemoglobinopathy

Clinical Case Reports ◽

10.1002/ccr3.941 ◽

2017 ◽

Vol 5 (6) ◽

pp. 1011-1012 ◽

Cited By ~ 4

Author(s):

Senan John Yasar ◽

Vivian Irene Ravn Berg ◽

Asim Ahmad ◽

Donald Doll

Keyword(s):

Oxygen Affinity ◽

Low Oxygen ◽

Low Oxygen Affinity

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Oxygen dependence of redox state of copper in cytochrome oxidase in vitro

Journal of Applied Physiology ◽

10.1152/jappl.1993.74.4.1622 ◽

1993 ◽

Vol 74 (4) ◽

pp. 1622-1627 ◽

Cited By ~ 44

Author(s):

Y. Hoshi ◽

O. Hazeki ◽

M. Tamura

Keyword(s):

Respiratory Rate ◽

Cytochrome Oxidase ◽

Near Infrared ◽

Energy State ◽

Oxygen Affinity ◽

Quantitative Information ◽

Low Oxygen ◽

Straight Line ◽

Oxygen Concentrations

To obtain quantitative information about tissue oxygenation from near-infrared signals, the oxygen dependencies of the redox states of both heme a+a3 and copper in cytochrome oxidase of isolated mitochondria were determined at low oxygen concentrations (10(-6)-10(-9) M) using leghemoglobin as an oxygen indicator. The maximum absorbance changes caused by the aerobic-anaerobic transition measured at 830–760 nm of copper in state 3, state 4, and the uncoupled state were 10, 17, and 5% of those at 605–620 nm of heme a+a3, respectively. Thus the relative absorbance ratio of copper to heme a+a3 could be used as a sensitive indicator for the mitochondrial energy state. The oxygen concentrations required for the half-maximal reduction of heme a+a3 varied with the energy state and the respiratory rate and were 7.8 x 10(-8) and 1.6 x 10(-7) M in state 4 and state 3, respectively. In contrast, that of copper was 7.5 x 10(-8) M and was independent of both the energy state and the respiratory rate. The relationship between the percent oxidation of heme a+a3 and copper in the aerobic-anaerobic transition did not show a straight-line relationship. This was referred to as the difference in oxygen affinity between these two chromophores. The deviation from the straight line was larger in state 3 than in state 4.(ABSTRACT TRUNCATED AT 250 WORDS)

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