Erythrocyte phosphates and hemoglobin function in monotremes and some marsupials

Area of Science:

• Comparative physiology
• Biochemistry
• Mammalian evolution

Background:

• Monotremes (platypus, echidna) and marsupials (Tasmanian devil, wallaby, possum) represent distinct evolutionary lineages.
• Understanding their hematologic and hemoglobin characteristics provides insights into mammalian adaptation.

Purpose of the Study:

• To analyze hematologic values and organic phosphate composition in red blood cells (RBCs) of monotremes and marsupials.
• To investigate the functional impact of various organic phosphates on hemoglobin oxygen affinity in these species.

Main Methods:

• Blood samples were collected from selected monotreme and marsupial species.
• Hematologic parameters, RBC organic phosphate levels, and hemoglobin composition were measured.
• The effect of ATP, 2,3-bisphosphoglycerate, and inositol pentakisphosphate on hemoglobin oxygen affinity was assessed.

Main Results:

• All studied species exhibited hemoglobin polymorphism with three distinct hemoglobin components.
• Organic phosphates (ATP, 2,3-bisphosphoglycerate, inositol pentakisphosphate) reduced hemoglobin oxygen affinity, with inositol pentakisphosphate having the greatest effect.
• Significant variations in RBC concentrations of 2,3-bisphosphoglycerate and ATP were observed across species.

Conclusions:

• Monotremes and marsupials share hemoglobin polymorphism, suggesting an ancient evolutionary trait.
• The differential effects of organic phosphates on hemoglobin function highlight unique adaptations in these mammals.
• These findings contribute to understanding the diversity of mammalian blood physiology and evolution.