Expressão gênica diferencial em animais cruzados Gir x Holandês infestados com o carrapato Rhipicephalus microplus

• Ano de defesa: 2011
• Autor(a) principal: Domingues, Robert
• Orientador(a): Guimarães, Simone Eliza Facioni
• Banca de defesa: Oliveira, Leandro Licursi de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Genética e Melhoramento
• Departamento: Genética animal; Genética molecular e de microrganismos; Genética quantitativa; Genética vegetal; Me
• País: BR
• Palavras-chave em Português: Bovino; Microarranjo; qRT-PCR; Resposta imune; Pele; Sangue periférico
• Palavras-chave em Inglês: Bovine; Microarray; qRT-PCR; Immune response; Skin; Peripheral blood
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::GENETICA E MELHORAMENTO DOS ANIMAIS DOMESTICOS
• Link de acesso: http://locus.ufv.br/handle/123456789/4760

Infestations by cattle tick Rhipicephalus microplus can lead to considerable production losses in cattle. The methods currently used to control these ectoparasites are not the ideal, whether because of low effectiveness or cause risk to the environment and human health. In general, animals of Zebu breeds are more resistant to ticks than taurine breeds, but greater understanding of these differences are necessary both for the development of more efficient methods and to assist in cattle breeding. The objective of this study was to enumerate differences of gene expression in peripheral blood and skin of resistant and susceptible animals infested with ticks. It was used, for this work, bovine extremes in resistance and susceptibility to tick from a population of F2 animals crossbred (Gir x Holstein) that showed a wide phenotypic variation. The samples of blood and skin were collected prior to infestation, 24 and 48 hours after infestation. In peripheral blood it was studied the genes CD25, CXCL8, CXCL10, FOXP3, IL10 e TNFα by qRT-PCR and at skin it was studied the global gene expression by using the technique of DNA microarrays. It was observed in the blood increased expression of genes that indicate an increased activity of γδ lymphocytes as regulatory cells in resistant animais, and in the skin it was observed greater expression of genes related to immune response, coagulation and complement cascades, adaptive immune response and component of tight junctions also in resistant animals. Thus, one could assume that part of the resistance to the tick is related to the prevention, by the host, of the flow of food to the hematophagous ectoparasites. Finally, some genes such as those encoding the protein claudin-1, coagulation factor FXIII, phospholipase I enzyme, and factors B, P and C4BP of complement system could be considered candidate genes related to tick resistance.