MICROSATELLITE MARKERS FOR PEDIGREE VЕRIFICATION IN CATTLE
Nikola Adamov, Ljupčo Mickov, Vladimir Petkov, Mihajlo
Adamov
Faculty of Veterinary Medicine,
Lazar Pop Trajkov 5-7, 1000 Skopje, Republic
of Macedonia
adamovn@gmail.com
In order to achieve efficient implementation of the
breeding programs that include selective reproduction, correct pedigree
information and relationships between the animals is the basic condition.
Breeding strategies in domesticated livestock are based on animal model
evaluations, which include all known genetic relationships between the animals
in the calculations. However,
as demonstrated in some studies, the main assumption of this model for
achieving unbiased evaluations – that all pedigrees and relationships are
correctly recorded, is not always fulfilled. Misidentified animals are expected
to bias the estimation of genetic parameters and breeding values and can
lead to loss in selection response and reduced genetic progress as they
are a function of the number of misidentified progeny. Errors in
pedigrees could also result in incorrect decisions about selective mating
of the animals, which could increase the inbreeding depression. In the
past, parentage/paternity testing in cattle has been carried out through
the blood group and the protein
polymorphism analysis, but because of some drawbacks, these tests have
been replaced with new ones that are based on detection of certain
"genetic markers". Most informative and most commonly used are
the microsatellite markers (Short Tandem Repeats) which are highly
polymorphic and are located on the noncoding intron regions of the bovine
genome. The advantage of microsatellite based tests is that theoretically
any sample containing nuclear DNA can be used for analysis, and when
genotyping recommended set of markers, the accuracy of the test is much higher
as the probability of detecting mistaken parentage is a direct function
of the polymorphism of the markers used. The research of the cattle
genome conducted in the past resulted
in identification of several thousand microsatellite loci, among which nine
most informative are recognized by the International Society for Animal
Genetics (ISAG) as "international marker set" and are
recommended as a minimal panel to be included in cattle pedigree
verification in order to facilitate the record exchange between
laboratories.
Key words:
bovine microsatellite markers; parentage/paternity testing; pedigree
verification
|
