title: Evaluation of reference genes for real-time PCR studies of Brazilian Somalis sheep infected by gastrointestinal nematodes.
abstract: Precise normalization with reference genes is necessary, in order to obtain reliable relative expression data in response to gastrointestinal nematode infection. By using sheep from temperate regions as models, three reference genes, viz., ribosomal protein LO (RPLO), glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and succinate dehydrogenase complex subunit A (SDHA), were investigated in the abomasum, abomasal lymph nodes and small intestine of Brazilian Somalis sheep, either resistant or susceptible to gastrointestinal nematodes infections. Real time PCR was carried out by using SYBR Green I dye, and gene stability was tested by geNorm. RPLO was an ideal reference gene, since its expression was constant across treatments, presented lower variation, and was ranked as the most stable in abomasum and lymph node tissues. On the other hand, SDHA was the most stable in the small intestine followed by RPLO and GAPDH. These findings demonstrate the importance of correctly choosing reference genes prior to relative quantification. In addition, we determined that reference genes used in sheep from temperate regions, when properly tested, can be applied in animals from tropical regions such as the Brazilian Somalis sheep.
authors.affiliation: Universidade Federal do Rio Grande do Norte, Natal, RN Brazil.
authors.forename: Lilian Giotto
authors.initials: LG
authors.lastname: Zaros
authors.forename: Luiz Lehmann
authors.initials: LL
authors.lastname: Coutinho
authors.forename: Lúcia Helena
authors.initials: LH
authors.lastname: Sider
authors.forename: Henrique Rocha
authors.initials: HR
authors.lastname: de Medeiros
authors.forename: Maria Rosalba Moreira das
authors.initials: MR
authors.lastname: Neves
authors.forename: Camila Loures
authors.initials: CL
authors.lastname: Benvenuti
authors.forename: Andrine Maria
authors.initials: AM
authors.lastname: do Carmo Navarro
authors.forename: Luiz
authors.initials: L
authors.lastname: da Silva Vieira