MVSc

This study was undertaken for finding the molecular genetic diversity
among dwarf cattle groups of Kerala namely Vechur, Highrange dwarf, Vatakara
and Kasargode using RAPD-PCR technique.
Genomic DNA was isolated from 101 animals belonging to the four cattle
groups using phenol: chloroform method. The mean yields of DNA isolated from
five ml of whole blood was 110.07 ± 9.4 ug and the average ratio between optical
densities at 260 and 280 nm was 1.6. The PCR conditions were standardized
with respect to annealing temperature (382c), magnesium chloride concentration
(1.5 mM) and the amount of Taq DNA polymerase (0.5 units/20 Ill). RAPD-PCR
analysis was performed in pooled DNA samples using 26 random
oligonucleotides. Individual sample analysis was done by selecting ten primers.
The degree of polymorphism obtained for the primers varied from 0 to 100 per
cent in different populations. The polymorphism of primers ILO 876, ILO 1127,
OPA 20, OPA 12, OPA 09 were higher for all groups tested. ILO 526, OPA 10,
OPA 01 and OPA 18 gave moderate levels of polymorphism whereas the
polymorphism given by OPA 06 was very low.
The primer [LO 1127 produced a distinct band which was present in half
of Vechur animals and in one Kasargode cattle. ILO 526 gave a low degree of
polymorphism in Kasargode cattle and moderate levels in other groups tested. A
predominant population specific band of 2.5 kb was identified in Highrange
dwarf cattle with primer OPA 06. When amplified with OPA 20, a band
(OPA 20 c) was noticed in Vechur animals with a frequency 0.07 and it was
absent in other animals. The primer OPA 18 produced two common bands and
the primer OPA 06 produced eight common bands. OPA 014, OPA 09 g and
OPA 12 g were the common bands present in all the animals tested when
respective primers were used.

The band sharing values obtained were higher for Vechur and Vatakara
animals (0.83 ± 0.00) and lower for Highrange dwarf and Kasargode animals
(0.81 ± 0.00), when within group band sharing was considered. The between
group band sharing value varied from 0.80 ± 0.00 (between Highrange dwarf and
Kasargode) to 0.83 ± 0.00 (between Vechur and Vatakara). This indicates that
Vechur and Vatakara populations are more similar than Highrange dwarf and
Kasargode cattle. The least squares analysis of variance of band sharing value
showed significant effects (P primer on band sharing. The percentage difference values calculated as a
measure of genetic divergence between groups were not significantly different
between Vechur and Vatakara and between Highrange dwarf and Vatakara. They
differed significantly between comparisons of Vechur-Highrange dwarf,
Vatakara-Kasargode, Vechur-Kasargode and Highrange dwarf-Kasargode
combinations. The mean average percentage difference calculated as a measure
of genetic dissimilarities between groups, ranged from 17.93 (between Vechur
and Vatakara) to 20.92 (between Highrange dwarf and Kasargode). The genetic
distance calculated was lowest between Vechur and Vatakara (0.006) and highest
between Highrange dwarf and Kasargode (0.046). The dendrogram prepared
showed mixing of animals of different genetic groups.
In the present study the molecular genetic diversity among four genetic
groups of dwarf cattle in Kerala was estimated using the RAPD-PCR technique.
It was observed that the Vechur and the Vatakara animals are genetically more
similar than the Highrange dwarf and Kasargode animals.