Genetic Diversity Study of Five Ethiopian Indigenous Bovine Breeds Using Microsatellite Markers
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Date
2011-05
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Addis Ababa University
Abstract
The current study describes the genetic variability within and among five Ethiopian indigenous
bovine breeds viz; Abigar, Boran, Horro, Guraghe and Sheko based on nine microsatellite
markers (TGLA227, ETH3, ETH10, ETH152, ETH225, BM2113, BM1824, ILSTS049 and
TGLA53). The Abigar breed represents the Sanga (cross between Bos taurus and Zebu breed)
cattle breed, the Boran and Guraghe highland are grouped under Zebu breed, the Horro breed
fall under Zenga (cross between Sanga and Zebu breed) cattle and the Sheko cattle belongs to
humpless shorthorn (Bos taurus).
Blood samples were taken randomly from10 unrelated animals from each cattle breed and DNA
was isolated for PCR amplification. The PCR products were resolved on eight or 10% nondenaturing
polyacrylamide gels, based on the size of the products, and visualized by GelRed
staining. Allelic frequencies, hetrozygosity values, polymorphic information content (PIC),
genetic differentiation and genetic distance were estimated. The allelic frequencies were also
tested for deviation from Hardy-Weinberg equilibrium (HWE).
The result of the current study indicated that the total numbers of alleles observed overall loci in
Abigar, Boran, Guraghe, Horro and Sheko were 67, 65, 54, 58 and 59, respectively. The breeds
showed deviation from HWE at least at one of the loci examined, except the Boran breed which
was found to be at HWE for all loci studied. The overall observed and expected hetrozygosity
values and PIC were 0.782±0.079, 0.847±0.050 and 0.828±0.057, respectively. The mean
observed hetrozygosity value in Abigra, Boran, Guraghe, Horro and Sheko were 0.800±0.071,
0.803±0.157, 0.761±0.109, 0.781±0.133 and 0.763±0.084, respectivey, The Nei’s expected
hetrozygosity values in these breeds were found to be 0.820±0.036, 0.798±0.065, 0.788±0.070,
0.780±0.063 and 0.783±0.049, respectively. Generally, the genetic differentiations between the
breeds were low. Moreover, non-significant (P>0.05) differentiation were noticed in the study
(between Boran and Guraghe, between Guraghe and Horro and between Boran and Horro).The
partitioning of genetic variability based on overall FST values indicated 2.2 % of variation was
due to between the breeds studied whereas the remaining (97.8%) was due to variation among
individuals. The inbreeding coefficients within and among were small, 0.070±0.031and
0.090±0.27, respectively. Genetic distance based on Nei’s corrected distance was found to be
least (0.027) between Boran and Guraghe and highest (0.229) between Boran and Sheko.
Generally, a dendrogram following UPGMA clustering generated based on Nei’s genetic
distance matrix agreed with the evolutionary history of the breeds studied.
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Biology