Genome-wide search for microsatellite markers associated with radiologic alterations in the navicular bone of Hanoverian warmblood horses.

This research aimed to identify the specific genetic factors involved in pathological changes in the navicular bone, a condition affecting Hanoverian warmblood horses. The analysis involved examining various familial groups and using microsatellite markers to pinpoint quantitive trait loci (QTLs) on the genome.

Objectives and Process

• The primary objective of the study was to locate the quantitative trait loci (QTLs), specific regions of the genome associated with pathological changes in the navicular bone in Hanoverian warmblood horses.
• The study involved seventeen paternal half-sibling groups, all of which totaled 192 individual horses. These groups were comprised of progeny and grandchildren that were chosen randomly from the same breed.
• The research focused on the analysis of three distinct traits: the deformation of the canales sesamoidales, and radiographic changes observed in both the contour and structure of the navicular bone.

Genome Analysis

• The study incorporated a genome scan that included 214 highly polymorphic microsatellite markers. Microsatellites are sequences of DNA that consist of repeating units of 1-6 base pairs in length.
• They’re known to be highly polymorphic because of their higher mutation rates, which involves the addition or deletion of repeating units. The polymorphic nature of these microsatellites makes them extremely useful in mapping genes associated with diseases.

Results

• The research led to the identification of genomic regions on equine chromosomes (ECA) 2, 3, 10, and 15 that were likely linked to the pathological changes observed. These regions were further analyzed using 53 additional microsatellites.
• The study found chromosome-wide significant QTLs on five different equine chromosomes (ECA2, 3, 4, 10, and 26). Within these, genome-wide significant QTLs were noticed on ECA2 at 48 cM and on ECA10 from 45.5 to 49.8 cM.
• This study is just the first step towards gaining a deeper understanding of the role of genetics in radiologic changes in the equine navicular bone. Further research is needed to fully understand the implications of these findings and their potential application in the prevention and treatment of these conditions in horses.