Genetic diversity of four cattle breeds using microsatellite markers

Abstract

-Four cattle breeds (Gyr, Nellore, Guzerat and Holstein) were analyzed by amplification of genomic DNA using microsatellite loci to evaluate the genetic diversity within and among them. DNA samples of 18 animals from each breed were collected to access the genetic content of them. Allele frequencies were calculated and used to generate a Nei's genetic distance matrix what was used to build a dendrogram following UPGMA clustering. As expected, Holstein breed was the most distinct from the other breeds: 1.15 in relation to Gyr, 1.12 in relation to Nellore and 0.94 in relation to Guzerat. The closest genetic distance was 0.25 between Guzerat and Nellore. A total of 64 alleles in all four breeds were detected using nine microsatellite primers. Each breed showed 53% of the total number of alleles. The average number of alleles per locus was 7.11 ± 3.21. The most informative locus was BMS1237 with 53% of observed heterozygosity and the least informative locus was BMS3004 with 12% only. The average heterozygosity detected for the nine loci were 35% and the expected value for Hardy-Weinberg equilibrium was 53%. This low heterozygosity suggests a high endogamy level among the animals sampled within each breed.Key Words: bovine, DNA, genetic diversity, marker, microsatellite Diversidade Genética de Quatro Raças Bovinas Utilizando Marcadores MicrossatélitesRESUMO -As raças bovinas Gir, Nelore e Guzerá (Bos indicus) e Holandesa (Bos taurus) foram analisadas pela amplificação do DNA genômico utilizando nove locos de microssatélites, visando avaliar a diversidade genética existente dentro e entre as raças. Foram utilizados 18 indivíduos puros para cada raça visando uma amostragem da constituição genética. As freqüências alélicas foram calculadas e utilizadas para gerar uma matriz de distâncias genéticas de Nei, que foi utilizada para a construção de um dendrograma com agrupamento pelo método UPGMA (média das distâncias). A raça Holandesa foi a mais distante geneticamente das demais: 1,15 em relação à Gir; 1,12 em relação à Nelore e 0,94 em relação à Guzerá. A menor distância genética obtida (0,25) foi entre as raças Guzerá e Nelore. Os nove primers de microssatélites utilizados geraram um total de 64 alelos para as quatro raças, sendo que cada raça apresentou em média 53% do total dos alelos. A média do número de alelos por loco foi de 7,11 ± 3,21. O loco mais informativo foi BMS1237 com uma heterozigosidade observada de 53%, enquanto que o loco menos informativo foi BMS3004 com 12%. A heterozigosidade média para os nove locos foi de 35% sendo que o esperado para o equilíbrio de Hardy-Weinberg é 53%. Esta baixa heterozigosidade sugere que, dentro de cada raça, os animais avaliados apresentam uma elevada endogamia.Palavras-chave: bovino, DNA, diversidade genética, marcador, microssatélite

Quantitative trait locus affecting birth weight on bovine chromosome 5 in a F2 Gyr x Holstein population

“…Machado et al (2003b) found that in a 5/8 Charolais 3/8 Zebu crossbred population heterozygosity was between 0.468 and 0.755 (average 0.646) for the four markers used in their research. In our study heterozygosity was between 0.578 and 1.0 (average 0.865) (Table 3), this value being higher than the average heterozygosity obtained with nine microsatellites for the Gyr (0.305) and Holstein (0.339) populations by Machado et al (2003a). In a study to incorporate more markers in the bovine genetic linkage map, Bishop et al (1994) found an average heterozygosity of 0.747 in Bos taurus X Bos indicus F 1 crosses.…”

Comparison of microsatellite and blood group diversity among different genotypes of cattle

“…These differences could be caused by the different origin of the breeds. A relevant distance between Holstein and another cattle breed was observed by Machado et al (2003). A similar genetic distance between Limousin and Charolais breeds (0.138) was observed by Maudet et al (2002).…”

“…The general heterozygosity was lower in the Chinese native population (0.69-0.76) (Zhou et al, 2005). The heterozygosity value observed in the Slovak Holstein population (0.707) was higher than that reported for North American Holsteins (0.61) by Vallejo et al (2003) and for the Holstein population (0.513) by Machado et al (2003).…”

Association of growth hormone gene polymorphism with quantitative characteristics of thin-tailed sheep using PCR-RFLP in Jambi province

“…This result does not vary much with the results of Kumari et al (2014) against 9 nations of sheep in India who obtain the A allele frequency (+) higher than the frequency of allele (-). According to Machado et al (2003), if the Ho value is lower than the He value, it indicates a degree of endogamy (mating within the group). Furthermore, Javanmard et al (2005) found that heterozygosity with a value below 50% indicates the low variation of a gene in the population.…”