Oxygen Supply from the Bird's Eye Perspective

Blank, Miriam; Kiger, Laurent; Thielebein, Anke; Gerlach, Frank; Hankeln, Thomas; Marden, Michael C.; Burmester, Thorsten

doi:10.1074/jbc.m111.224634

Cited by 32 publications

(29 citation statements)

References 40 publications

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“…At the beginning of the experiment (t = 0 s), the absorption spectrum was acquired in the oxygenated state (17.83% O 2 ). The spectrum showed one strong peak at 540 nm and another peak at 575 nm, which is equivalent to the reported spectra of Hb in red blood cells from chicken [ 44 ]. The trapped RBCs were then deoxygenated by a flow of (0-0.5% O 2 ) EC buffer solution and a time series of spectra showed the gradual transformation from the oxygenated to the deoxygenated state.…”

Section: Resultssupporting

confidence: 80%

“…The absorption spectra were binomially smoothed by a data-analyzing software program (IGOR Pro, USA). The region from 520 - 600 nm was used to study the typical spectral peaks of the Q-bands of the oxygenated and deoxygenated states of haemoglobin (Hb) [ 44 ]. The built in function “Binomial smoothing” as a Gaussian filter was applied to reduce the variability of data as well as to present clear and noise-free spectra [ 45 ].…”

Section: Methodsmentioning

confidence: 99%

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A lab-on-a-chip for hypoxic patch clamp measurements combined with optical tweezers and spectroscopy- first investigations of single biological cells

et al. 2015

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The response and the reaction of the brain system to hypoxia is a vital research subject that requires special instrumentation. With this research subject in focus, a new multifunctional lab-on-a-chip (LOC) system with control over the oxygen content for studies on biological cells was developed. The chip was designed to incorporate the patch clamp technique, optical tweezers and absorption spectroscopy. The performance of the LOC was tested by a series of experiments. The oxygen content within the channels of the LOC was monitored by an oxygen sensor and verified by simultaneously studying the oxygenation state of chicken red blood cells (RBCs) with absorption spectra. The chicken RBCs were manipulated optically and steered in three dimensions towards a patch-clamp micropipette in a closed microfluidic channel. The oxygen level within the channels could be changed from a normoxic value of 18% O 2 to an anoxic value of 0.0-0.5% O 2. A time series of 3 experiments were performed, showing that the spectral transfer from the oxygenated to the deoxygenated state occurred after about 227 ± 1 s and a fully developed deoxygenated spectrum was observed after 298 ± 1 s, a mean value of 3 experiments. The tightness of the chamber to oxygen diffusion was verified by stopping the flow into the channel system while continuously recording absorption spectra showing an unchanged deoxygenated state during 5400 ± 2 s. A transfer of the oxygenated absorption spectra was achieved after 426 ± 1 s when exposing the cell to normoxic buffer. This showed the long time viability of the investigated cells. Successful patching and sealing were established on a trapped RBC and the whole-cell access (Ra) and membrane (Rm) resistances were measured to be 5.033 ± 0.412 M Ω and 889.7 ± 1.74 M Ω respectively.

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Section: Resultssupporting

confidence: 80%

Section: Methodsmentioning

confidence: 99%

A lab-on-a-chip for hypoxic patch clamp measurements combined with optical tweezers and spectroscopy- first investigations of single biological cells

et al. 2015

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“…Experiments in Xenopus demonstrated that this gene is expressed in a diverse range of tissues and cell types (Fuchs et al 2006), but its physiological function remains a mystery. Finally, the globin E ( GbE ) gene has so far only been documented in the genomes of birds (Blank et al 2011a; Hoffmann et al 2010b, 2011; Kugelstadt et al 2004). This bird-specific protein appears to perform a Mb-like function in regulating oxygen supply to photoreceptor cells in the avascular avian retina (Blank et al 2011a), although a role in regulating cellular redox homeostasis is also possible.…”

Section: The Functional Diversification Of Vertebrate Globinsmentioning

confidence: 99%

“…In fact, the ancestral linkage arrangement of these genes is still retained in the genomes of Xenopus , anole lizard, and platypus, as GbY is located downstream from the 3’ end of the α-globin gene cluster in each of these taxa (Fuchs et al 2006; Hoffmann et al 2010b; Patel et al 2008). Likewise, comparisons of conserved synteny revealed that the GbE and Mb genes also represent the paralogous products of a tandem gene duplication that occurred prior to the diversification of gnathostome vertebrates, and the ancestral linkage arrangement of these two genes is still retained in the avian genome (Blank et al 2011a; Hoffmann et al 2011). …”

Section: Gene Duplication Genome Duplication and The Evolution Omentioning

confidence: 99%

Gene duplication, genome duplication, and the functional diversification of vertebrate globins

Storz

Opazo

Hoffmann

2013

Molecular Phylogenetics and Evolution

107

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The functional diversification of the vertebrate globin gene superfamily provides an especially vivid illustration of the role of gene duplication and whole-genome duplication in promoting evolutionary innovation. For example, key globin proteins that evolved specialized functions in various aspects of oxidative metabolism and oxygen signaling pathways (hemoglobin [Hb], myoglobin [Mb], and cytoglobin [Cygb]) trace their origins to two whole-genome duplication events in the stem lineage of vertebrates. The retention of the proto-Hb and Mb genes in the ancestor of jawed vertebrates permitted a physiological division of labor between the oxygen-carrier function of Hb and the oxygen-storage function of Mb. In the Hb gene lineage, a subsequent tandem gene duplication gave rise to the proto α- and β-globin genes, which permitted the formation of multimeric Hbs composed of unlike subunits (α2β2). The evolution of this heteromeric quaternary structure was central to the emergence of Hb as a specialized oxygen-transport protein because it provided a mechanism for cooperative oxygen-binding and allosteric regulatory control. Subsequent rounds of duplication and divergence have produced diverse repertoires of α- and β-like globin genes that are ontogenetically regulated such that functionally distinct Hb isoforms are expressed during different stages of prenatal development and postnatal life. In the ancestor of jawless fishes, the proto Mb and Hb genes appear to have been secondarily lost, and the Cygb homolog evolved a specialized respiratory function in blood-oxygen transport. Phylogenetic and comparative genomic analyses of the vertebrate globin gene superfamily have revealed numerous instances in which paralogous globins have convergently evolved similar expression patterns and/or similar functional specializations in different organismal lineages.

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“…Changes in the size and membership composition of the α- and β-globin gene families may produce changes in the developmental regulation of Hb synthesis and may therefore constrain or potentiate functional divergence between Hb isoforms that incorporate the products of paralogous globin genes ( Berenbrink et al 2005 ; Berenbrink 2007 ; Opazo et al 2008a , 2008b ; Runck et al 2009 ; Hoffmann, Storz, et al 2010 ; Storz, Hoffmann, et al 2011 ; Storz, Opazo, et al 2011 ; Grispo et al 2012 ; Damsgaard et al 2013 ; Opazo et al 2013 ; Storz et al 2013 ). Indeed, over a deeper timescale of animal evolution, the co-option and functional divergence of more ancient members of the globin gene superfamily have played a well-documented role in evolutionary innovation ( Hoffmann, Opazo, et al 2010 ; Blank et al 2011 ; Hoffmann, Opazo, Hoogewijs, et al 2012 ; Hoffmann, Opazo, Storz, 2012 ; Hoogewijs et al 2012 ; Schwarze and Burmester 2013 ; Schwarze et al 2014 ).…”

Section: Introductionmentioning

confidence: 99%

Gene Turnover in the Avian Globin Gene Families and Evolutionary Changes in Hemoglobin Isoform Expression

Opazo

Hoffmann

Natarajan

et al. 2014

Molecular Biology and Evolution

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The apparent stasis in the evolution of avian chromosomes suggests that birds may have experienced relatively low rates of gene gain and loss in multigene families. To investigate this possibility and to explore the phenotypic consequences of variation in gene copy number, we examined evolutionary changes in the families of genes that encode the α- and β-type subunits of hemoglobin (Hb), the tetrameric α2β2 protein responsible for blood-O2 transport. A comparative genomic analysis of 52 bird species revealed that the size and membership composition of the α- and β-globin gene families have remained remarkably constant during approximately 100 My of avian evolution. Most interspecific variation in gene content is attributable to multiple independent inactivations of the αD-globin gene, which encodes the α-chain subunit of a functionally distinct Hb isoform (HbD) that is expressed in both embryonic and definitive erythrocytes. Due to consistent differences in O2-binding properties between HbD and the major adult-expressed Hb isoform, HbA (which incorporates products of the αA-globin gene), recurrent losses of αD-globin contribute to among-species variation in blood-O2 affinity. Analysis of HbA/HbD expression levels in the red blood cells of 122 bird species revealed high variability among lineages and strong phylogenetic signal. In comparison with the homologous gene clusters in mammals, the low retention rate for lineage-specific gene duplicates in the avian globin gene clusters suggests that the developmental regulation of Hb synthesis in birds may be more highly conserved, with orthologous genes having similar stage-specific expression profiles and similar functional properties in disparate taxa.

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Oxygen Supply from the Bird's Eye Perspective

Cited by 32 publications

References 40 publications

A lab-on-a-chip for hypoxic patch clamp measurements combined with optical tweezers and spectroscopy- first investigations of single biological cells

A lab-on-a-chip for hypoxic patch clamp measurements combined with optical tweezers and spectroscopy- first investigations of single biological cells

Gene duplication, genome duplication, and the functional diversification of vertebrate globins

Gene Turnover in the Avian Globin Gene Families and Evolutionary Changes in Hemoglobin Isoform Expression

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