Mitochondrial Introgression With Potential Functional Effects in North American Yak

Area of Science:

• Genomics
• Mitochondrial DNA analysis
• Animal breeding

Background:

• Domestic yaks (Bos grunniens) have interbred with cattle, but the extent in North America is unclear.
• Mitochondrial DNA (mtDNA) provides insights into maternal lineage and evolutionary history.

Purpose of the Study:

• To investigate the mitochondrial origins of North American yak.
• To explore potential differences in energy metabolism between yak mitotypes.

Main Methods:

• Sequencing of complete mitochondrial DNA from 12 North American yaks.
• Bioinformatic analysis including genome alignment and variant identification.
• Seahorse ATP Rate Assay to measure cellular energy metabolism in isolated satellite cells.

Main Results:

• Nine unique mitotypes were identified in North American yaks, clustering into two distinct groups.
• Six haplotypes grouped with Bos indicus, while three clustered with Bos grunniens.
• Yak with the Bos grunniens mitotype exhibited significantly lower total energy metabolism.

Conclusions:

• North American yaks possess at least two distinct mitochondrial origins, predating their introduction to the continent.
• The observed metabolic differences may reflect adaptations to diverse ancestral environments and selective breeding pressures.