Vascular Expression of Hemoglobin Alpha in Antarctic Icefish Supports Iron Limitation as Novel Evolutionary Driver
Frigid temperatures of the Southern Ocean are known to be an evolutionary driver in Antarctic fish. For example, many fish have reduced red blood cell (RBC) concentration to minimize vascular resistance. Via the oxygen-carrying protein hemoglobin, RBCs contain the vast majority of the body’s iron, w...
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ftdoajarticles:oai:doaj.org/article:c29f96a691244be9b8e6b1c946d50eab 2023-05-15T13:38:06+02:00 Vascular Expression of Hemoglobin Alpha in Antarctic Icefish Supports Iron Limitation as Novel Evolutionary Driver Bruce A. Corliss Leon J. Delalio T. C. Stevenson Keller Alexander S. Keller Douglas A. Keller Bruce H. Corliss Jody M. Beers Shayn M. Peirce Brant E. Isakson 2019-11-01T00:00:00Z https://doi.org/10.3389/fphys.2019.01389 https://doaj.org/article/c29f96a691244be9b8e6b1c946d50eab EN eng Frontiers Media S.A. https://www.frontiersin.org/article/10.3389/fphys.2019.01389/full https://doaj.org/toc/1664-042X 1664-042X doi:10.3389/fphys.2019.01389 https://doaj.org/article/c29f96a691244be9b8e6b1c946d50eab Frontiers in Physiology, Vol 10 (2019) hemoglobin alpha evolution vasculature iron flux endothelial cells Physiology QP1-981 article 2019 ftdoajarticles https://doi.org/10.3389/fphys.2019.01389 2022-12-31T14:51:37Z Frigid temperatures of the Southern Ocean are known to be an evolutionary driver in Antarctic fish. For example, many fish have reduced red blood cell (RBC) concentration to minimize vascular resistance. Via the oxygen-carrying protein hemoglobin, RBCs contain the vast majority of the body’s iron, which is known to be a limiting nutrient in marine ecosystems. Since lower RBC levels also lead to reduced iron requirements, we hypothesize that low iron availability was an additional evolutionary driver of Antarctic fish speciation. Antarctic Icefish of the family Channichthyidae are known to have an extreme alteration of iron metabolism due to loss of RBCs and two iron-binding proteins, hemoglobin and myoglobin. Loss of hemoglobin is considered a maladaptive trait allowed by relaxation of predator selection since extreme adaptations are required to compensate for the loss of oxygen-carrying capacity. However, iron dependency minimization may have driven hemoglobin loss instead of a random evolutionary event. Given the variety of functions that hemoglobin serves in the endothelium, we suspected the protein corresponding to the 3’ truncated Hbα fragment (Hbα-3’f) that was not genetically excluded by icefish may still be expressed as a protein. Using whole mount confocal microscopy, we show that Hbα-3’f is expressed in the vascular endothelium of icefish retina, suggesting this Hbα fragment may still serve an important role in the endothelium. These observations support a novel hypothesis that iron minimization could have influenced icefish speciation with the loss of the iron-binding portion of Hbα in Hbα-3’f, as well as hemoglobin β and myoglobin. Article in Journal/Newspaper Antarc* Antarctic Icefish Southern Ocean Directory of Open Access Journals: DOAJ Articles Antarctic Southern Ocean Frontiers in Physiology 10 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
hemoglobin alpha evolution vasculature iron flux endothelial cells Physiology QP1-981 |
spellingShingle |
hemoglobin alpha evolution vasculature iron flux endothelial cells Physiology QP1-981 Bruce A. Corliss Leon J. Delalio T. C. Stevenson Keller Alexander S. Keller Douglas A. Keller Bruce H. Corliss Jody M. Beers Shayn M. Peirce Brant E. Isakson Vascular Expression of Hemoglobin Alpha in Antarctic Icefish Supports Iron Limitation as Novel Evolutionary Driver |
topic_facet |
hemoglobin alpha evolution vasculature iron flux endothelial cells Physiology QP1-981 |
description |
Frigid temperatures of the Southern Ocean are known to be an evolutionary driver in Antarctic fish. For example, many fish have reduced red blood cell (RBC) concentration to minimize vascular resistance. Via the oxygen-carrying protein hemoglobin, RBCs contain the vast majority of the body’s iron, which is known to be a limiting nutrient in marine ecosystems. Since lower RBC levels also lead to reduced iron requirements, we hypothesize that low iron availability was an additional evolutionary driver of Antarctic fish speciation. Antarctic Icefish of the family Channichthyidae are known to have an extreme alteration of iron metabolism due to loss of RBCs and two iron-binding proteins, hemoglobin and myoglobin. Loss of hemoglobin is considered a maladaptive trait allowed by relaxation of predator selection since extreme adaptations are required to compensate for the loss of oxygen-carrying capacity. However, iron dependency minimization may have driven hemoglobin loss instead of a random evolutionary event. Given the variety of functions that hemoglobin serves in the endothelium, we suspected the protein corresponding to the 3’ truncated Hbα fragment (Hbα-3’f) that was not genetically excluded by icefish may still be expressed as a protein. Using whole mount confocal microscopy, we show that Hbα-3’f is expressed in the vascular endothelium of icefish retina, suggesting this Hbα fragment may still serve an important role in the endothelium. These observations support a novel hypothesis that iron minimization could have influenced icefish speciation with the loss of the iron-binding portion of Hbα in Hbα-3’f, as well as hemoglobin β and myoglobin. |
format |
Article in Journal/Newspaper |
author |
Bruce A. Corliss Leon J. Delalio T. C. Stevenson Keller Alexander S. Keller Douglas A. Keller Bruce H. Corliss Jody M. Beers Shayn M. Peirce Brant E. Isakson |
author_facet |
Bruce A. Corliss Leon J. Delalio T. C. Stevenson Keller Alexander S. Keller Douglas A. Keller Bruce H. Corliss Jody M. Beers Shayn M. Peirce Brant E. Isakson |
author_sort |
Bruce A. Corliss |
title |
Vascular Expression of Hemoglobin Alpha in Antarctic Icefish Supports Iron Limitation as Novel Evolutionary Driver |
title_short |
Vascular Expression of Hemoglobin Alpha in Antarctic Icefish Supports Iron Limitation as Novel Evolutionary Driver |
title_full |
Vascular Expression of Hemoglobin Alpha in Antarctic Icefish Supports Iron Limitation as Novel Evolutionary Driver |
title_fullStr |
Vascular Expression of Hemoglobin Alpha in Antarctic Icefish Supports Iron Limitation as Novel Evolutionary Driver |
title_full_unstemmed |
Vascular Expression of Hemoglobin Alpha in Antarctic Icefish Supports Iron Limitation as Novel Evolutionary Driver |
title_sort |
vascular expression of hemoglobin alpha in antarctic icefish supports iron limitation as novel evolutionary driver |
publisher |
Frontiers Media S.A. |
publishDate |
2019 |
url |
https://doi.org/10.3389/fphys.2019.01389 https://doaj.org/article/c29f96a691244be9b8e6b1c946d50eab |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic Icefish Southern Ocean |
genre_facet |
Antarc* Antarctic Icefish Southern Ocean |
op_source |
Frontiers in Physiology, Vol 10 (2019) |
op_relation |
https://www.frontiersin.org/article/10.3389/fphys.2019.01389/full https://doaj.org/toc/1664-042X 1664-042X doi:10.3389/fphys.2019.01389 https://doaj.org/article/c29f96a691244be9b8e6b1c946d50eab |
op_doi |
https://doi.org/10.3389/fphys.2019.01389 |
container_title |
Frontiers in Physiology |
container_volume |
10 |
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1766101522152685568 |