| Sumario: | The 3¢ untranslated region (3¢ UTR) of the bovine natural resistanceassociated macrophage gene (NRAMP1 or SLC11A1) was genotyped in
Colombian Creole Blanco Orejinegro (BON) (Bos taurus) (n = 140) and
Zebu Brahman (Bos indicus) (Z) (n = 20) cattle and their crosses
(BON · Zebu Brahman [B · Z] [n = 10]; Zebu Brahman · BON [Z · B]
[n = 10]), and in animals from a Holstein · BON (H · B) (n = 10) cross.
Direct sequencing and single-strand conformation polymorphism analysis (SSCP) helped in detecting the polymorphic behaviour. The association between resistance to brucellosis infection and SSCP genotype was
evaluated using a macrophage in vitro killing assay employing a virulent
Brucella abortus strain. The 3¢ UTR (GT) repeated polymorphism was gentoyped and its association with resistance to brucellosis was evaluated.
When all breeds were grouped, a high frequency in the homozygote
GT12 (AA genotype) (0.823) and a very low frequency in the homozygote GT10 (BB genotype) (0.047) were detected. The BON (0.963), Z · B
(0.60) and H · B (1.00) cattle showed high GT12 allele frequencies,
unlike that seen for the B · Z and Zebu cattle (0.3002 and 0.218,
respectively). The GT10 allele was only found in the Zebu cattle (0.391).
A significant association (p < 0.001) was found between the B. abortus
macrophage in vitro killing assay phenotypes and the bovine SLC11A1 3¢
UTR genotypes, which suggests that the A allele may be associated with
resistance. Because only nine animals had the BB genotype, the results
require some confirmation in more extensive populations.
|
|---|