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Background: Vertebrate evolution is accompanied by a substantial conservation of transcriptional programs with more than a third of unique orthologous genes showing constrained levels of expression. Moreover, there are genes and exons exhibiting excellent expression stability according to RNA-seq data across a panel of eighteen tissues including the ovary (Human Body Map 2.0). Results: We hypothesized that orthologs of these exons would also be highly uniformly expressed across neonatal ovaries of the horse, which would render them appropriate reference genes (RGs) for normalization of reverse transcription quantitative PCR (RT-qPCR) data in this context. The expression stability of eleven novel RGs (C1orf43, CHMP2A, EMC7, GPI, PSMB2, PSMB4, RAB7A, REEP5, SNRPD3, VCP and VPS29) was assessed by RT-qPCR in ovaries of seven neonatal fillies and compared to that of the expressed repetitive element ERE-B, two universal (OAZ1 and RPS29) and four traditional RGs (ACTB, GAPDH, UBB and B2M). Expression stability analyzed with the software tool RefFinder top ranked the normalization factor constituted of the genes SNRPD3 and VCP, a gene pair that is not co-expressed according to COEXPRESdb and GeneMANIA. The traditional RGs GAPDH, B2M, ACTB and UBB were only ranked 3rd and 12th to 14th, respectively. Conclusions: The functional diversity of the novel RGs likely facilitates expression studies over a wide range of physiological and pathological contexts related to the neonatal equine ovary. In addition, this study augments the potential for RT-qPCR-based profiling of human samples by introducing seven new human RG assays (C1orf43, CHMP2A, EMC7, GPI, RAB7A, VPS29 and UBB). [ABSTRACT FROM AUTHOR]

In Austria, vaccination coverage against Bordetella pertussis infections during infancy is estimated at around 90%. Within the last years, however, the number of pertussis cases has increased steadily, not only in children but also in adolescents and adults, indicating both insufficient herd immunity and vaccine coverage. Waning immunity in the host and/or adaptation of the bacterium to the immunised hosts could contribute to the observed re-emergence of pertussis. In this study we therefore addressed the genetic variability in B. pertussis strains from several Austrian cities. Between the years 2002 and 2008, 110 samples were collected from Vienna (n = 32), Linz (n = 63) and Graz (n = 15) by nasopharyngeal swabs. DNA was extracted from the swabs, and bacterial sequence polymorphisms were examined by MLVA (multiple-locus variable number of tandem repeat analysis) (n = 77), by PCR amplification and conventional Sanger sequencing of the polymorphic regions of the prn (pertactin) gene (n = 110), and by amplification refractory mutation system quantitative PCR (ARMS-qPCR) (n = 110) to directly address polymorphisms in the genes encoding two pertussis toxin subunits (ptxA and ptxB), a fimbrial adhesin (fimD), tracheal colonisation factor (tcfA), and the virulence sensor protein (bvgS). Finally, the ptxP promoter region was screened by ARMS-qPCR for the presence of the ptxP3 allele, which has been associated with elevated production of pertussis toxin. The MLVA analysis revealed the highest level of polymorphisms with an absence of MLVA Type 29, which is found outside Austria. Only Prn subtypes Prn1/7, Prn2 and Prn3 were found with a predominance of the non-vaccine type Prn2. The analysis of the ptxA, ptxB, fimD, tcfA and bvgS polymorphisms showed a genotype mixed between the vaccine strain Tohama I and a clinical isolate from 2006 (L517). The major part of the samples (93%) displayed the ptxP3 allele. The consequences for the vaccination strategy are discussed. [ABSTRACT FROM AUTHOR]

Reference genes (RGs) with uniform expression are used for normalization of reverse transcription quantitative PCR (RT-qPCR) data. Their optimization for a specific biological context, e.g. a specific tissue, has been increasingly considered. In this article, we compare RGs identified by expression data meta-analysis restricted to the context tissue, the jejunum of Mus musculus domesticus, i) to traditional RGs, ii) to expressed interspersed repeated DNA elements, and iii) to RGs identified by meta-analysis of expression data from diverse tissues and conditions. To select the set of candidate RGs, we developed a novel protocol for the cross-platform meta-analysis of microarray data. The expression stability of twenty-four putative RGs was analysed by RT-qPCR in at least 14 jejunum samples of the mouse strains C57Bl/6N, CD1, and OF1. Across strains, the levels of expression of the novel RGs Plekha7, Zfx, and Ube2v1 as well as of Oaz1 varied less than two-fold irrespective of genotype, sex or their combination. The gene set consisting of Plekha7 and Oaz1 showed superior expression stability analysed with the tool RefFinder. The novel RGs are functionally diverse. This facilitates expression studies over a wide range of conditions. The highly uniform expression of the optimized RGs in the jejunum points towards their involvement in tightly regulated pathways in this tissue. We also applied our novel protocol of cross-microarray platform meta-analysis to the identification of RGs in the duodenum, the ileum and the entire small intestine. The selection of RGs with improved expression stability in a specific biological context can reduce the number of RGs for the normalization step of RT-qPCR expression analysis, thus reducing the number of samples and experimental costs. [ABSTRACT FROM AUTHOR]