Ontogeny of hemoglobin-oxygen binding and multiplicity in the obligate air-breathing fish Arapaima gigas

Autor: Roy E. Weber, Christian Damsgaard, Angela Fago, Adalberto L. Val, Luc Moens
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Comparative biochemistry and physiology : A : molecular & integrative physiology
Weber, R E, Damsgaard, C, Fago, A, Val, A L & Moens, L 2022, ' Ontogeny of hemoglobin‑oxygen binding and multiplicity in the obligate air-breathing fish Arapaima gigas ', Comparative Biochemistry and Physiology-Part A: Molecular & Integrative Physiology, vol. 268, 111190 . https://doi.org/10.1016/j.cbpa.2022.111190
ISSN: 1095-6433
Popis: The evolutionary and ontogenetic changes from water-to air-breathing result in major changes in the cardio-respiratory systems. However, the potential changes in hemoglobin's (Hb) oxygen binding properties during ontogenetic transitions to air-breathing remain poorly understood. Here we investigated Hb multiplicity and O(2 )binding in hemolysates and Hb components from juveniles and adults of the obligate air-breathing pirarucu (Arapaima gigas) that starts life as water-breathing hatchlings. Contrasting with previous electrophoresis studies that report one or two isoHbs in adults, isoelectric focusing (IEF) resolved the hemolysates from both stages into four major bands, which exhibited identical O-2 binding properties (i.e. O-2 affinities, cooperativity coefficients, and sensitivities to pH and the major organic phosphate effectors), also as compared to the cofactor-free hemolysates. Of note, the multiplicity pattern recurred upon reanalyses of the most-abundant fractions iso-lated from the juvenile and the adult stages, suggesting possible stabilization of different quaternary states with different isoelectric points during the purification procedure. The study demonstrates unchanged Hb-O-2 binding properties during development, despite the pronounced differences in O-2 availability between the two media, which harmonizes with findings based on a broader spectrum of interspecific comparisons. Taken together, these results disclose that obligate air-breathing in Arapaima is not contingent upon changes in Hb multiplicity and O-2 binding characteristics.
Databáze: OpenAIRE
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