A DNA barcode is a DNA fragment used to identify species. For land plants, DNA fragments of plastid genome could be the primary consideration. Unfortunately, most of the plastid candidate barcodes lack species-level resolution. The identification of DNA barcodes of high resolution at species level is critical to the success of DNA barcoding in plants. We searched the available plastid genomes for the most variable regions and tested the best candidates using both a large number of tree species and seven well-sampled plant groups. Two regions of the plastid gene ycf1, ycf1a and ycf1b, were the most variable loci that were better than existing plastid candidate barcodes and can serve as a barcode of land plants. Primers were designed for the amplification of these regions, and the PCR success of these primers ranged from 82.80% to 98.17%. Of 420 tree species, 357 species could be distinguished using ycf1b, which was slightly better than the combination of matK and rbcL. For the well-sampled representative plant groups, ycf1b generally performed better than any of the matK, rbcL and trnH-psbA. We concluded that ycf1a or ycf1b is the most variable plastid genome region and can serve as a core barcode of land plants.

BackgroundMetformin plays an important role in diabetes treatment. Studies have shown that the combined use of oral hypoglycemic medications is more effective than metformin monotherapy. In this double-blind, randomized, placebo-controlled, multicenter trial, we evaluated whether Jinlida, a Chinese herbal medicine, enhances the glycemic control of metformin in type 2 diabetes patients whose HbA1c was ineffectively controlled with metformin alone.MethodsA total of 186 diabetes patients were enrolled in this double-Blind, randomized, placebo-controlled, multicenter trial. Subjects were randomly allocated to receive either Jinlida (9 g) or the placebo TID for 12 consecutive weeks. All subjects in both groups also continuously received their metformin without any dose change. During this 12-week period, the HbA1c, FPG, 2h PG, body weight, BMI were assessed. HOMA insulin resistance (HOMA-IR) and β-cell function (HOMA- β) were also evaluated.ResultsAt week 12, compared to the HbA1c level from week 0, the level of the Jinlida group was reduced by 0.92 ± 1.09% and that of the placebo group was reduced by 0.53 ± 0.94%. The 95% CI was 0.69 - 1.14 for the Jinlida group vs. 0.34 - 0.72 for the placebo group. There was a very significant HbA1c reduction between the two groups after 12 weeks (p < 0.01). Both FG and 2h PG levels of the Jinlida group and placebo group were reduced from week 0. There were a very significant FG and 2h PG level reductions between the two groups after 12 weeks (both p < 0.01). The Jinlida group also showed improved β-cell function with a HOMA-β increase (p < 0.05). No statistical significance was observed in the body weight and BMI changes. No serious adverse events were reported.ConclusionJinlida significantly enhanced the hypoglycemic action of metformin when the drug was used alone. This Chinese herbal medicine may have a clinical value as an add-on medication to metformin monotherapy.Trial RegistrationChinese Clinical Trial Register ChiCTR-TRC-13003159

Background Schistosomiasis japonica is a serious debilitating and sometimes fatal disease. Accurate diagnostic tests play a key role in patient management and control of the disease. However, currently available diagnostic methods are not ideal, and the detection of the parasite DNA in blood samples has turned out to be one of the most promising tools for the diagnosis of schistosomiasis. In our previous investigations, a 230-bp sequence from the highly repetitive retrotransposon SjR2 was identified and it showed high sensitivity and specificity for detecting Schistosoma japonicum DNA in the sera of rabbit model and patients. Recently, 29 retrotransposons were found in S. japonicum genome by our group. The present study highlighted the key factors for selecting a new perspective sensitive target DNA sequence for the diagnosis of schistosomiasis, which can serve as example for other parasitic pathogens.Methodology/Principal FindingsIn this study, we demonstrated that the key factors based on the bioinformatic analysis for selecting target sequence are the higher genome proportion, repetitive complete copies and partial copies, and active ESTs than the others in the chromosome genome. New primers based on 25 novel retrotransposons and SjR2 were designed and their sensitivity and specificity for detecting S. japonicum DNA were compared. The results showed that a new 303-bp sequence from non-long terminal repeat (LTR) retrotransposon (SjCHGCS19) had high sensitivity and specificity. The 303-bp target sequence was amplified from the sera of rabbit model at 3 d post-infection by nested-PCR and it became negative at 17 weeks post-treatment. Furthermore, the percentage sensitivity of the nested-PCR was 97.67% in 43 serum samples of S. japonicum-infected patients.Conclusions/SignificanceOur findings highlighted the key factors based on the bioinformatic analysis for selecting target sequence from S. japonicum genome, which provide basis for establishing powerful molecular diagnostic techniques that can be used for monitoring early infection and therapy efficacy to support schistosomiasis control programs.