A cluster of four globin genes from the Antarctic fish Notothenia coriiceps (original) (raw)
Related papers
The Major Adult α-Globin Gene of Antarctic Teleosts and Its Remnants in the Hemoglobinless Icefishes
Journal of Biological Chemistry
The icefishes of the Southern Ocean (family Channichthyidae, suborder Notothenioidei) are unique among vertebrates in their inability to synthesize hemoglobin. We have shown previously (Cocca, E., Ratnayake-Lecamwasam, M., Parker, S. K., Camardella, L., Ciaramella, M., di Prisco, G., and Detrich, H. W., III (1995)Proc. Natl. Acad. Sci. U. S. A. 92, 1817–1821) that icefishes retain inactive genomic remnants of adult notothenioid α-globin genes but have lost the gene that encodes adult β-globin. Here we demonstrate that loss of expression of the major adult α-globin, α1, in two species of icefish (Chaenocephalus aceratus and Chionodraco rastrospinosus) results from truncation of the 5′ end of the notothenioid α1-globin gene. The wild-type, functional α1-globin gene of the Antarctic yellowbelly rockcod, Notothenia coriiceps, contains three exons and two A + T-rich introns, and its expression may be controlled by two or three distinct promoters. Retained in both icefish genomes are a po...
Journal of Biological Chemistry, 1998
The icefishes of the Southern Ocean (family Channichthyidae, suborder Notothenioidei) are unique among vertebrates in their inability to synthesize hemoglobin. We have shown previously (Cocca, E., Ratnayake-Lecamwasam, M., Parker, S. K., Camardella, L., Ciaramella, M., di Prisco, G., and Detrich, H. W., III (1995) Proc. Natl. Acad. Sci. U. S. A. 92, 1817-1821) that icefishes retain inactive genomic remnants of adult notothenioid ␣-globin genes but have lost the gene that encodes adult -globin. Here we demonstrate that loss of expression of the major adult ␣-globin, ␣1, in two species of icefish (Chaenocephalus aceratus and Chionodraco rastrospinosus) results from truncation of the 5 end of the notothenioid ␣1-globin gene. The wild-type, functional ␣1-globin gene of the Antarctic yellowbelly rockcod, Notothenia coriiceps, contains three exons and two A ؉ T-rich introns, and its expression may be controlled by two or three distinct promoters. Retained in both icefish genomes are a portion of intron 2, exon 3, and the 3-untranslated region of the notothenioid ␣1-globin gene. The residual, nonfunctional ␣-globin gene, no longer under positive selection pressure for expression, has apparently undergone random mutational drift at an estimated rate of 0.12-0.33%/million years. We propose that abrogation of hemoglobin synthesis in icefishes most likely resulted from a single mutational event in the ancestral channichthyid that deleted the entire -globin gene and the 5 end of the linked ␣1-globin gene.
Biogeography and adaptation of Notothenioid fish: Hemoglobin function and globin–gene evolution
Gene, 2007
The recognition of the important role of the polar habitats in global climate changes has awakened great interest in the evolutionary biology of polar organisms. They are exposed to strong environmental constraints, and it is important to understand how they have adapted to cope with these challenges and to what extent adaptations may be upset by current climate changes.
Molecular Biology and Evolution, 2012
As the Southern Ocean cooled to À1.8°C over the past 40 My, the teleostean clade Notothenioidei diversified and, under reduced selection pressure for an oxygen-transporting apparatus, became less reliant on hemoglobin and red blood cells. At the extreme of this trend, the crown group of Antarctic icefishes (Channichthyidae) lost both components of oxygen transport. Under the decreased selection scenario, we hypothesized that the Antarctic dragonfishes (Bathydraconidae, the red-blooded sister clade to the icefishes) evolved lower blood hemoglobin concentrations because their globin gene complexes (a-and b-globin gene pairs linked by a regulatory intergene) transcribe globin mRNAs less effectively than those of basal notothenioids (e.g., the Nototheniidae [notothens]). To test our hypothesis, we 1) sequenced the a/b-intergenes of the adult globin complexes of three notothen and eight dragonfish species and 2) measured globin transcript levels in representative species from each group. The typical nototheniid intergene was ;3-4 kb in length. The bathydraconid intergenes resolved into three subclasses (long [3.8 kb], intermediate [3.0 kb], and short [1.5-2.3 kb]) that corresponded to the three subclades proposed for the taxon. Although they varied in length due to indels, the three notothen and eight dragonfish intergenes contained a conserved ;90-nt element that we have previously shown to be required for globin gene transcription. Using the quantitative polymerase chain reaction, we found that globin mRNA levels in red cells from one notothen species and from one species of each dragonfish subclade were equivalent statistically. Thus, our results indicate that the bathydraconids have evolved adult globin loci whose regulatory intergenes tend to be shorter than those of the more basal nototheniids yet are equivalent in transcriptional efficacy. Their low blood hemoglobin concentrations are most likely due to reduction in hematocrit.
Genomic remnants of alpha-globin genes in the hemoglobinless antarctic icefishes
Proceedings of the National Academy of Sciences, 1995
Alone among piscine taxa, the antarctic icefishes (family Channichthyidae, suborder Notothenioidei) have evolved compensatory adaptations that maintain normal metabolic functions in the absence of erythrocytes and the respiratory oxygen transporter hemoglobin. Although the uniquely "colorless" or "white" condition of the blood of icefishes has been recognized since the early 20th century, the status of globin genes in the icefish genomes has, surprisingly, remained unexplored. Using a-and f-globin cDNAs from the antarctic rockcod Notothenia coriiceps (family Nototheniidae,
Tracking the evolutionary loss of hemoglobin expression by the white-blooded Antarctic icefishes
Gene, 2002
The blood of Antarctic icefishes (family Channichthyidae, suborder Notothenioidei) is completely devoid of hemoglobin. Icefishes have developed compensatory adaptations that reduce oxygen demand and enhance oxygen transport. Oxygen delivery to tissues occurs by carrying the gas physically dissolved in the plasma. To evaluate the evolutionary pathway leading to the icefish hemoglobinless phenotype, the adult and embryonic/juvenile gene complexes from a closely related, red-blooded notothenioid species were isolated and characterized. The hybridization pattern of notothenioid adult globin cDNAs showed that the genomes of three icefish species retain transcriptionally inactive a1-globin-related DNA sequences, which are identical truncated variants of the a1-globin gene of the red-blooded fish, containing part of intron 2, all of exon 3, and the 3 0 -untranslated region. The icefish genomes have no b-globin genes. Furthermore, Southern blots of genomic DNA from red-and white-blooded (two species) notothenioids, probed with fragments of the genes flanking the ends of the embryonic/juvenile complex, indicated that icefishes have also lost embryonic/juvenile globin genes. It is proposed that inability to express hemoglobin arose from a single, large-scale deletional event, which removed all icefish globin genes with the exception of the 3 0 end of a1. q 2002 Published by Elsevier Science B.V.
FEBS Letters, 1989
The blood of the Antarctic fish Nototheniu coriiceps neglecta contains two hemoglobins, Hb 1 and Hb 2, which have a b-chain in common. We have elucidated the primary structure of the b-chain (146 residues) and of the a-chains (142 residues) of the two hemoglobins. The two a-chains differ from each other by 51 residues; in comparison with globin sequences of temperate fishes, the a-chain of Hb 1 is more similar to that of bluefin tuna than to the a-chain of Hb 2 of the same species.
The hemoglobin system of Antarctic and non-Antarctic notothenioid fishes
Comparative Biochemistry and Physiology Part A: Physiology, 1997
Studies of the hemoglobin system of fish of the suborder Notuthenioidei have heen extended ttr non-Antarctic species Pset&phritis urvillii and Not&e&x angustata. The two species belong tu &milks chat were the hrst to diverge within the suborder. The degree of amino acid sequence identity with Antarctic nototheni~kls and other non-Antarctic fish species is analyzed with respect to phyletic and ecological divergence.
Deep Sea Research Part II: Topical Studies in Oceanography, 2006
With the notable exception of Antarctic icefishes, haemoglobin (Hb) is present in all vertebrates. In polar fish, Hb evolution has included adaptations with implications at the biochemical, physiological and molecular levels. Cold adaptation has been shown to be also linked to small changes in primary structure and post-translational modifications in proteins, including hydrophobic remodelling and increased flexibility. A wealth of knowledge is available on the oxygentransport system of fish inhabiting Antarctic waters, but very little is known on the structure and function of Hb of non-Antarctic notothenioid fishes. The comparison of the biochemical and physiological adaptations between cold-adapted and non-cold-adapted species is a powerful tool to understand whether (and to what extent) extreme environments require specific adaptations or simply select for phenotypically different life styles. This study focuses on structure, function and molecular phylogeny of Hb in Antarctic and non-Antarctic notothenioid fishes. The rationale is to use the primary structure of Hb as tool of choice to gain insight into the pathways of the evolution history of a and b globins of notothenioids and also as a basis for reconstructing the phylogenetic relationships among Antarctic and non-Antarctic species. r