ArticleMilk
protein is the most valuable component of milk from a dietary point of view.
More than 95% of ruminants’ milk proteins are coded by six structural genes: two whey proteins
(α
–
lactalbumin and β
–
lactoglobulin) and four caseins (α
S1
–
and α
S2
–
caseins,
β
–
casein,
κ
–
casein). The object of the research was the genetic polymorphisms of milk protein genes in
populations of cows and breeding bulls of milk producing breeds in Latvia. The aim was to
promote cow breeding in Latvia
by developing and testing mo
lecular genetics analyses for future
quantity and quality analysis of the dairy cows’ population in Latvia,
based on the research of
genes encoding milk protein polymorphism. In methodology the molecular markers were chosen
which would be suitable for char
acterization of polymorphism of five milk protein genes in the
population of dairy cows reared in Latvia. As a genetic method chosen the Restriction Fragment
Length Polymorphism (RFLP) method and most analysed alleles of milk proteins. Using data of
719 DN
A samples of dairy cows, the analysis of Latvian cows’ population was carried out
through six SNP of five milk protein genes: C
SN1S1
c.
–
175
A
>
G,
CSN2
–
c.
4451
A
>
C,
CSN3
c.
11625
C
>
T
and
c.
11661
A
>
C,
LAA
c.15A
>
G and
LGB
c.
3106T
>
C.
The results of
PCR
-
RFLP analysis showed, as it was expected, that all genotypes were found in the populations
