[Sequence comparing of mtDNA D-Loop varied region in Chinese Mongolian horse and External Thoroughbred horse].

This study examines the differences in the mitochondrial DNA D-Loop varied region in both Chinese Mongolian horses and External Thoroughbred horses. The research found that both breeds have significant variations in this region, with the average rate of mutations higher in Thoroughbred horses.

Objective of the Study

• The objective of this research was to compare the extent of variation in a specific region of mitochondrial DNA known as the D-Loop in two different types of horses: Chinese Mongolian and External Thoroughbred. The researchers hoped to characterize the differences in mutation rates and occurrences in these two breeds to better understand genetic diversity and evolution.

Method of the Study

• The researchers selected eight horses for the study – four Chinese Mongolian horses and four External Thoroughbred horses. They then extracted and analyzed a 400 base pair (bp) sequence from the D-Loop region of the mitochondrial DNA from each horse. The choice of this genomic region was important as the D-Loop region is known to be highly polymorphic, which makes it useful for population studies and tracking evolutionary changes.

Results of the Study

• The research found that the average nucleotide mutational rate was different between the two types of horses. It was 3.69% in the Chinese Mongolian horses and 4.00% in the Thoroughbreds. This suggests that the Thoroughbreds might have a slightly faster rate of evolution or genetic change.
• The study identified three types of mutations in the D-Loop regions: Transition, Transversion, and Deletion. Of these, the transition type mutation was the most frequent, consistent with the general understanding that transitions are typically more common than transversions in evolution.
• The scientists also identified a lot of variation in the mutant loci and length mutations across the eight horses. This indicates a high level of genetic diversity.

Conclusion of the Study

• Overall, the researchers concluded that there is a significant amount of polymorphism in the D-Loop region of the mitochondrial DNA in both Chinese Mongolian and External Thoroughbred horses. This study helped illuminate the substantial genetic diversity within these horse breeds and contributes to our understanding of the genetic changes and mutations that mark their evolution.