Wild and cultivated allele effects on rice phenotypic traits in reciprocal backcross populations between Oryza rufipogon and two cultivars, O. sativa Nipponbare and IR36.

A total of four populations of reciprocal backcross recombinant inbred lines were produced from a cross between a wild accession of Oryza rufipogon W630 and two major cultivars, O. sativa Japonica Nipponbare and Indica IR36. Using these populations, quantitative trait locus (QTL) analysis for eight morphological traits (culm length, panicle length, days to heading, panicle shape, pericarp color, hull color, seed shattering and seed awning) was carried out, and the putative QTL regions were compared among the populations. The QTLs with strong allele effects were commonly detected for culm length, panicle shape, pericarp color and hull color in all four populations, and their peak locations were close to the major genes of sd1, Spr3, Rc and Bh4, respectively. For panicle length and days to heading, some QTL regions overlapped between two or three populations. In the case of seed shattering and seed awning, strong wild allele effects at major loci were observed only in the populations with cultivated backgrounds. Since the wild and cultivated alleles have never been evaluated in the reciprocal genetic backgrounds, the present results provide new information on gene effects in breeding and domestication studies.

Establishment of a novel diagnostic test algorithm for human T-cell leukemia virus type 1 infection with line immunoassay replacement of western blotting: a collaborative study for performance evaluation of diagnostic assays in Japan.

BACKGROUND: The reliable diagnosis of human T-cell leukemia virus type 1 (HTLV-1) infection is important, particularly as it can be vertically transmitted by breast feeding mothers to their infants. However, current diagnosis in Japan requires a confirmatory western blot (WB) test after screening/primary testing for HTLV-1 antibodies, but this test often gives indeterminate results. Thus, this collaborative study evaluated the reliability of diagnostic assays for HTLV-1 infection, including a WB-based one, along with line immunoassay (LIA) as an alternative to WB for confirmatory testing. RESULTS: Using peripheral blood samples from blood donors and pregnant women previously serologically screened and subjected to WB analysis, we analyzed the performances of 10 HTLV-1 antibody assay kits commercially available in Japan. No marked differences in the performances of eight of the screening kits were apparent. However, LIA determined most of the WB-indeterminate samples to be conclusively positive or negative (an 88.0% detection rate). When we also compared the sensitivity to HTLV-1 envelope gp21 with that of other antigens by LIA, the sensitivity to gp21 was the strongest. When we also compared the sensitivity to envelope gp46 by LIA with that of WB, LIA showed stronger sensitivity to gp46 than WB did. These findings indicate that LIA is an alternative confirmatory test to WB analysis without gp21. Therefore, we established a novel diagnostic test algorithm for HTLV-1 infection in Japan, including both the performance of a confirmatory test where LIA replaced WB on primary test-reactive samples and an additional decision based on a standardized nucleic acid detection step (polymerase chain reaction, PCR) on the confirmatory test-indeterminate samples. The final assessment of the clinical usefulness of this algorithm involved performing WB analysis, LIA, and/or PCR in parallel for confirmatory testing of known reactive samples serologically screened at clinical laboratories. Consequently, LIA followed by PCR (LIA/PCR), but neither WB/PCR nor PCR/LIA, was found to be the most reliable diagnostic algorithm. CONCLUSIONS: Because the above results show that our novel algorithm is clinically useful, we propose that it is recommended for solving the aforementioned WB-associated reliability issues and for providing a more rapid and precise diagnosis of HTLV-1 infection.

[Correlation of quantification of major bcr-abl mRNA between TMA (transcription mediated amplification) method and real-time quantitative PCR].

Imatinib mesylate has significantly improved the outcome of patients with CML. In the IRIS trial, major molecular response (MMR), which is defined as the achievement of > or =3 log reduction in bcr-abl mRNA from the standardized baseline, was observed in 40% of CML patients by 12 months. Achievement of an MMR at 18 months is associated with 100% probability of transformation-free survival at 60 months, and MMR is an important goal of therapy. The nucleic acid quantitative "DNA probe FR Amp-CML" kit based on the transcription-mediated amplification method, can measure major bcr-abl mRNA in peripheral blood leukocytes. In this study, we studied the clinical usefulness of Amp-CML for monitoring minimum residual disease by comparison with the European standard nucleic acid quantitative method and real-time quantitative PCR (RQ-PCR) with GAPDH as an internal control, using peripheral leukocytes obtained from patients receiving imatinib treatment. The results indicated that Amp-CML had a significant correlation with Fusion Quant M-BCR (R>0.971, P<0.01), a standard nucleic acid quantitative method used in Europe and RQ-PCR (R>0.974, P<0.01), especially in samples with more than 100 copies/microg RNA of major bcr-abl mRNA. These data suggest that Amp-CML is reliable for monitoring major bcr-abl mRNA in patients having achieved an MMR.