Detection of a novel single nucleotide polymorphism and imprinted status analysis of the Ras protein-specific guanine nucleotide-releasing factor 1 gene in domestic pigs.

The aim of this study was to determine the imprinting status of the Ras protein-specific guanine nucleotide-releasing factor 1 (Rasgrf1) gene in domestic pigs. In this study, a 228-bp partial sequence located in exon 14 and a 193-bp partial sequence located in exon 1 of the Rasgrf1 gene in domestic pigs were obtained. A novel single nucleotide polymorphism, a G/A transition, was identified in Rasgrf1 exon 14, and then the reciprocal Berkshire x Wannan black F1 hybrid model and the reverse transcription-polymerase chain reaction-restriction fragment length polymorphism method were used to detect the imprinting status of the porcine Rasgrf1 gene at the 1-day-old developmental stage. Imprinting analysis showed that, compared to the imprinted expression of the Rasgrf1 gene in mouse and rat, a variable imprinting status was observed in domestic pigs. In principle, the porcine Rasgrf1 gene was maternally expressed in the liver and small intestine, paternally expressed in the lung, and biallelically expressed in brain, heart, spleen, kidney, stomach, pancreas, fat, testis, ovary, longissimus dorsi, and pituitary tissues. In conclusion, our results indicated that the Rasgrf1 gene shows both species- and tissue-specific variation in imprinted expression.

IFNG +874T/A, IL10 -1082G/A and TNF -308G/A polymorphisms in association with tuberculosis susceptibility: a meta-analysis study.

Susceptibility to infectious diseases is influenced by genetic background and efficient cellular immune activation is responsible for protection. In tuberculosis (TB), interferon-gamma (IFNgamma) is crucial to control intracellular growth of Mycobacterium tuberculosis while interleukin-10 (IL-10) has an antagonistic role. Tumor necrosis factor (TNF) is a central mediator of granuloma formation and control of bacilli spread synergizing with IFNgamma to hamper M. tuberculosis infection. Single nucleotide polymorphisms (SNPs) located at these genes could influence cytokine levels and regulate resistance and susceptibility to TB. The aim of this study was to determine the association of the interferon-gamma gene (IFNG) +874T/A, interleukin-10 gene (IL10) -1082G/A and tumor necrosis factor gene (TNF) -308G/A SNPs with TB in several populations using meta-analysis. We searched for association studies correlating these polymorphisms and TB using pre-established keywords in Medline. Meta-analysis was conducted with random effects models to account for heterogeneity between studies. Eleven studies were included in the IFNG +874T/A meta-analysis, while eight were used for the IL10 -1082G/A, and 10 were employed for TNF -308G/A. Data were analyzed in respect to associations between alleles, genotypes and minor allele carriers. Statistically significant results were found only for IFNG. The +874T allele of IFNG showed a protective significant association (OR = 0.75; 95% CI, 0.634-0.887; P = 0.0008). Though not significant, IL10 presented a trend towards protection when only studies with pulmonary TB patients were considered. This data reinforces the critical importance of IFNG +874T/A as a genetic marker for TB resistance and this information can be used for better design of a TB vaccine.