A human minisatellite sequence reveals DNA polymorphism in the equine species.

The study uses a human VNTR probe to identify DNA polymorphism in unrelated quarter horse breed horses, exhibiting its potential for individual identification and pedigree analysis.

Research Context

• Genetic polymorphism is a natural variation in the DNA sequence among individuals of the same species. It’s a key factor in the biological diversity and evolution of species. In this research, the authors explore DNA polymorphism in equine species, specifically the quarter horse breed.
• This research involves the use of a human variable number tandem repeats (VNTR) probe. VNTRs are short sequences of DNA, repeated in tandem and vary in number among individuals. This makes them suitable for genetic fingerprinting and other genetic identification applications.

Procedure

• The study started with Southern blot analysis of equine DNA. Southern blotting is a method used in molecular biology for detection of a specific DNA sequence. It entailed digesting the equine DNA with the restriction endonuclease Hinfl, a type of enzyme that cuts DNA at specific sites.
• A human VNTR probe, labelled with 32 PdCTP (a radioisotope), was employed to detect specific sequences in the equine DNA. The interaction and hybridization between the probe and the equine DNA were then studied through autoradiography. Autoradiography is a technique that uses X-ray film to visualize radioactively labelled molecules or fragments.

Findings

• The results showed a highly polymorphic pattern of restriction fragments. This is significant, as it indicates a high level of genetic variability in the quarter horse breed, which can be revealed through the use of a heterologous (human) probe.
• As a conclusion, the authors propose that the human VNTR probe can be effectively used for the identification of individual horses and pedigree analysis in the equine species. This can be beneficial for practices such as breeding and genetic disease marking.