Artículos de revistas
Haplotypes of the bovine IgG2 heavy gamma chain in tick-resistant and tick-susceptible breeds of cattle
Fecha
2011Registro en:
IMMUNOGENETICS, v.63, n.5, p.319-324, 2011
0093-7711
10.1007/s00251-011-0515-y
Autor
CARVALHO, Wanessa Araujo
IANELLA, Patricia
ARNOLDI, Frederico G. C.
CAETANO, Alexandre Rodrigues
MARUYAMA, Sandra Regina
FERREIRA, Beatriz Rossetti
CONTI, Luis Henrique Andreucci
SILVA, Marcia Ramos Monteiro da
PAULA, Jose Otavio F.
MAIA, Antonio Augusto Mendes
SANTOS, Isabel K. Ferreira de Miranda
Institución
Resumen
Bovines present contrasting, heritable phenotypes of infestations with the cattle tick, Rhipicephalus (Boophilus) microplus. Tick salivary glands produce IgG-binding proteins (IGBPs) as a mechanism for escaping from host antibodies that these ectoparasites ingest during blood meals. Allotypes that occur in the constant region of IgG may differ in their capacity to bind with tick IGBPs; this may be reflected by the distribution of distinct allotypes according to phenotypes of tick infestations. In order to test this hypothesis, we investigated the frequency of haplotypes of bovine IgG2 among tick-resistant and tick-susceptible breeds of bovines. Sequencing of the gene coding for the heavy chain of IgG2 from 114 tick-resistant (Bos taurus indicus, Nelore breed) and tick-susceptible (B. t. taurus, Holstein breed) bovines revealed SNPs that generated 13 different haplotypes, of which 11 were novel and 5 were exclusive of Holstein and 3 of Nelore breeds. Alignment and modeling of coded haplotypes for hinge regions of the bovine IgG2 showed that they differ in the distribution of polar and hydrophobic amino acids and in shape according to the distribution of these amino acids. We also found that there was an association between genotypes of the constant region of the IgG2 heavy chain with phenotypes of tick infestations. These findings open the possibility of investigating if certain IgG allotypes hinder the function of tick IGBPs. If so, they may be markers for breeding for resistance against tick infestations.