RESUMEN
Natural resistance-associated macrophage protein 1 and 2 encoding genes (Nramp1 and Nramp2) are related to many diseases. We cloned the cDNA of chicken Nramp1 and Nramp2 genes, characterized their expression and polymorphisms, and investigated the association of some SNPs with resistance to salmonellosis. The Nramp1 cDNA was 1746 bp long and the Nramp2 cDNA was 1938 bp long. These cDNAs are similar to previously reported cDNAs, varying by two and one amino acids, respectively. The chicken Nramp1 gene expressed predominantly in liver, thymus and spleen in both females and males. The Nramp2 gene expressed in almost all tissues, but predominantly in breast muscle, leg muscle, cerebrum, cerebellum, lung, kidney, and heart in both females and males. We identified 45 SNPs and 2 indels in the chicken Nramp1 gene; three of 13 SNPs in the exons were missense mutations (Arg223Gln, Ala273Glu and Arg497Gln). Association analysis indicated that A24101991G is significantly associated with chicken salmonellosis resistance. These results will be useful for functional investigation of chicken Nramp1 and Nramp2 genes.
Asunto(s)
Proteínas de Transporte de Catión/genética , Pollos/genética , Infecciones por Salmonella/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Pollos/microbiología , Clonación Molecular , ADN Complementario/genética , Exones , Femenino , Estudios de Asociación Genética/métodos , Masculino , Datos de Secuencia Molecular , Filogenia , Polimorfismo de Nucleótido Simple , Infecciones por Salmonella/prevención & control , Análisis de Secuencia de ADNRESUMEN
The dopamine D2 receptor (DRD2) is a crucial mediator for normal physiological processes. We cloned the pig DRD2 gene, investigated its distribution in tissues and identified polymorphisms by RT-PCR, quantitative real-time PCR and direct sequencing. Two Yorkshire pigs from Guangdong Academy of Agricultural Sciences (Guangzhou, China) were selected to clone the gene and investigate its expression; 16 individuals from four pig breeds (Yorkshire, Landrace, small-ear spotted, and Xinchang) were used to scan the variations. The two transcripts (DRD2L and DRD2S), obtained through insertion or deletion of exon 5 and part of 3'UTR, were found to encode 444- and 415-amino acid proteins, respectively. The 574-bp indel in 3'UTR comprises five miRNA targeting sites, based on bioinformatics predictions. The pig DRD2 gene expresses predominantly in the pituitary gland, and then in oviducts and the hypothalamus. Both DRD2L and DRD2S mRNA were detected in cerebrum, cerebellum, hypothalamus, pituitary gland, back muscle, oviduct, uterus, and testis tissues; DRD2L was more abundant than DRD2S. The DRD2 gene is located on chromosome 9 and contains seven exons. Sixty-one different sequences were identified in this gene; among seven in the coding region, only one altered the encoded amino acid. These findings will help us understand the functions of the DRD2 gene in pigs.