Hemoglobin polymorphism in Equus przewalskii and E. caballus analyzed by isoelectric focusing.

This research has compared the hemoglobins of Przewalski’s horse and the domestic horse through isoelectric focusing and peptide analysis. This comparison has revealed two alpha-globin chain polymorphisms in Przewalski’s horses, similar to those in domestic horses, with electrofocusing subsequently confirming these observations.

Methodology and Findings

• The researchers conducted an in-depth comparison of the hemoglobins present in Przewalski’s horse, Equus przewalskii, and the domestic horse, E. caballus. This was achieved using isoelectric focusing and peptide analysis.
• Notably, they found two separate alpha-globin chain polymorphisms in Przewalski’s horses that also exist in domestic horses. Polymorphisms refer to the presence of genetic variation within a population, including variations in DNA sequences, such as those found in the alpha-globin chains—a component of hemoglobin.
• These alpha-globin chain polymorphisms are not just random variations, but they can actually reliably inform the phenotype of the hemoglobin which can be accurately determined through isoelectric focusing. It is a powerful technique used to separate different molecular species based on their isoelectric point, therefore helping to identify and analyze the hemoglobin phenotypes.

Confirmation of Findings and Further Observation

• These determinations of hemoglobin through electrofocusing were confirmed by comparing to amino acid composition analyses of purified tryptic peptides. This comparison serves as an additional layer of authentication for the results obtained from the initial isoelectric focusing assessment.
• Furthermore, the researchers analyzed the rare hemoglobin phenotypes observed in a family of Norwegian trotting horses for additional confirmation and comparison. This provided extra evidence to validate their initial findings and offer further insights into hemoglobin polymorphisms.
• The hemoglobin genotypes of fifteen Przewalski’s horses were determined using these methods. They were able to observe the inheritance of hemoglobin haplotypes in these horses. This indicates a pattern of transmission of these hemoglobin variations from parents to offspring, revealing a genetic basis for these observed polymorphisms.