Fluorescence resonance energy transfer-based real-time polymerase chain reaction method without DNA extraction for the genotyping of F5, F2, F12, MTHFR, and HFE.

Blood samples are extensively used for the molecular diagnosis of many hematological diseases. The daily practice in a clinical laboratory of molecular diagnosis in hematology involves using a variety of techniques, based on the amplification of nucleic acids. Current methods for polymerase chain reaction (PCR) use purified genomic DNA, mostly isolated from total peripheral blood cells or white blood cells (WBC). In this paper we describe a real-time fluorescence resonance energy transfer-based method for genotyping directly from blood cells. Our strategy is based on an initial isolation of the WBCs, allowing the removal of PCR inhibitors, such as the heme group, present in the erythrocytes. Once the erythrocytes have been lysed, in the LightCycler(®) 2.0 Instrument, we perform a real-time PCR followed by a melting curve analysis for different genes (Factors 2, 5, 12, MTHFR, and HFE). After testing 34 samples comparing the real-time crossing point (CP) values between WBC (5×10(6) WBC/mL) and purified DNA (20 ng/µL), the results for F5 Leiden were as follows: CP mean value for WBC was 29.26±0.566 versus purified DNA 24.79±0.56. Thus, when PCR was performed from WBC (5×10(6) WBC/mL) instead of DNA (20 ng/µL), we observed a delay of about 4 cycles. These small differences in CP values were similar for all genes tested and did not significantly affect the subsequent analysis by melting curves. In both cases the fluorescence values were high enough, allowing a robust genotyping of all these genes without a previous DNA purification/extraction.

Development and evaluation of a real-time PCR assay for the quantitative detection of Theileria annulata in cattle.

BACKGROUND: The tick-borne apicomplexan bovine parasite Theileria annulata is endemic in many tropical and temperate areas, including Minorca (Balearic Islands, Spain). Real-time PCR is widely used for the detection of piroplasms but quantification is not commonly considered. RESULTS: We developed a real-time quantitative PCR (qPCR) assay for the detection and quantification of T. annulata that included an internal amplification control (IAC) to monitor for the presence of potential inhibitors. Specificity, sensitivity, precision, linear range and PCR efficiency were calculated and different methods for transformation of quantification cycle (Cq) values into quantities (Q) were evaluated. The assay was able to detect (100% probability) and quantify (linear response) 100 gene copies, and clinical sensitivity was set at 10 T. annulata per µl of blood. The assay was then validated on 141 bovine blood samples analyzed in parallel by a Luminex® suspension array, showing the utility of the qPCR assay developed here for the detection and quantification of the parasite in field conditions. Once validated it was used to monitor T. annulata parasitaemia throughout a year in 8 carrier animals from a farm in Minorca. CONCLUSIONS: The developed qPCR assay offers a reliable and simple way to quantify T. annulata infection loads, which could prove crucial in studying the role of carrier animals as a source of the infection, or assessing the efficacy of treatment and control measures.

Mediterranean theileriosis and other tick transmitted piroplasmoses in cattle in Minorca (Balearic Islands, Spain): the effect of tick control on prevalence levels analyzed by reverse line blot (RLB) macroarrays.

Mediterranean theileriosis, caused by Theileria annulata, is endemic in Minorca (Balearic Islands, Spain). The present study analyzes the prevalence of piroplasm infections in cattle in Minorca using reverse line blot (RLB) macroarrays, as well as the effect of herd tick control on those prevalence levels. One hundred and nineteen animals from 12 herds were sampled in representative areas of the island. Information was gathered regarding tick control for the animals (frequency and acaricide used) in each herd. More than 87% of the animals were positive for the presence of piroplasm species. Theileria annulata and Theileria buffeli were observed in all sampled herds (mean prevalence 53.3% for T. annulata and 69.75% for T. buffeli). The mean prevalence was 5.7% for Babesia bigemina. A significantly higher prevalence of Theileria spp. was observed in herds that grazed in, or near, forested areas. Theileria annulata prevalence was significantly lower in herds that followed tick control and was related to the frequency of the applied treatments. Theileria buffeli and B. bigemina prevalences were not affected by tick control for the herds. The results indicate that despite tick control, Mediterranean theileriosis remains endemic in Minorca. Adequate control measures and vaccination approaches are required to improve the situation of Mediterranean theileriosis on the island.

Higher processing rates of Alu-containing sequences in kidney tumors and cell lines with overexpressed Alu-mRNAs.

Tumor cell growth and differentiation involve several molecular mechanisms that control gene expression and define specific genomic molecular profiles in cancer cells. Among these mechanisms, it has been shown that Alu-repetitive sequences are capable of regulating gene expression at transcriptional and posttranscriptional levels, and also of modulating cellular growth, differentiation and tumor suppression. Furthermore, repetitive sequences have also been implicated in alternative RNA splicing, although the specific mechanisms involved remain unknown. Nonetheless, exactly what the involvement of Alu-containing sequences in tumor cell growth and differentiation is or to what extent they might be related to tumorigenesis or to alternative splicing is not yet clear. In order to address some of these issues, we analyzed the level of expression of Alu-containing sequences in renal tumors and cell lines and their association with immunoprecipitated ribonucleoprotein splicing complexes in nuclear RNA fractions. Over-expression of Alu-containing sequences was detected in the poly(A)-RNA fractions of all analyzed tumors and cell lines. Furthermore, Alu-sequences were associated with tumor cell growth and differentiation and found overexpressed in purified small nuclear ribonucleoprotein fractions. Overall, our results suggest the involvement of Alu-sequences in the overexpression of Alu-containing-mRNAs in human tumors, and also higher processing rates of Alu-containing sequences at the spliceosome associated with tumor cell growth and differentiation.