Genetic differences in the serum proteome of horses, donkeys and mules are detectable by protein profiling.

The research article investigates the differences in the serum protein profiles of horses, donkeys, and mules. The study claims that these differences may be due to the unique genetic properties of each species and contribute to species-specific characteristics.

Study Objective

• The research aimed to analyze the specific proteomes (the entire set of proteins expressed by a genome) and post-translational modifications (PTM) of proteins present in horses, donkeys, and mules. PTMs can alter protein properties and therefore, may introduce unique traits in each species.

Methodology

• The research analyzed and compared the serum protein profiles of five animals from each species. It used anionic ProteinChips® in combination with surface-enhanced laser desorption ionisation-time of flight Mass Spectrometer, a technique known for determining the differences in protein structures.
• The changes in the PTM of the protein Transthyretin (TTR) present in the serum of each species were also analysed. The study used immunoprecipitation in combination with matrix-assisted laser desorption ionisation-time of flight Mass Spectrometer to achieve this.

Results

• The analysis revealed species-specific differences in the proteome. There were protein peaks (indicative of protein presence and abundance) that were unique to each species. Some peaks were present in all three species, while others were specific to either donkeys and mules, horses and mules, or horses alone.
• The molecular weight of TTR in horses and donkeys differed by 30 Da. Both species exhibited several modified forms of TTR in addition to the native form.
• The mass spectra for mules represented a combination of the TTR spectra of horses and donkeys. This is in line with mules’ mixed genetic heritage as the offspring of a male donkey (jack) and a female horse (mare).

Conclusion

• The study determined significant differences in the proteomes of horses, donkeys, and mules, likely due to the genetic differences among these species. It suggests that mules, despite being the product of a horse and donkey, have a proteome more similar to donkeys than to horses.