Optimal Frequency of Hepatitis C Virus (HCV) RNA Testing for Detection of Acute HCV Infection Among At-risk People With Human Immunodeficiency Virus: A Multicenter Study.

Using 3-stage pooled-plasma hepatitis C virus (HCV) RNA testing performed quarterly among at-risk people with human immunodeficiency virus (PWH), we found that if testing had been performed every 6 or 12 months, 58.6%-91.7% of PWH who recently acquired HCV would be delayed for diagnosis and might contribute to onward HCV transmission with longer durations.

Parallel Speciation of Wild Rice Associated with Habitat Shifts.

The occurrence of parallel speciation strongly implies the action of natural selection. However, it is unclear how general a phenomena parallel speciation is since it was only shown in a small number of animal species. In particular, the adaptive process and mechanisms underlying the process of parallel speciation remain elusive. Here, we used an integrative approach incorporating population genomics, common garden, and crossing experiments to investigate parallel speciation of the wild rice species Oryza nivara from O. rufipogon. We demonstrated that O. nivara originated multiple times from different O. rufipogon populations and revealed that different O. nivara populations have evolved similar phenotypes under divergent selection, a reflection of recurrent local adaptation of ancient O. rufipogon populations to dry habitats. Almost completed premating isolation was detected between O. nivara and O. rufipogon in the absence of any postmating barriers between and within these species. These results suggest that flowering time is a "magic" trait that contributes to both local adaptation and reproductive isolation in the origin of wild rice species. Our study thus demonstrates a convincing case of parallel ecological speciation as a consequence of adaptation to new environments.

Gold-catalyzed 6-exo-dig cycloisomerization: a versatile approach to functionalized phenanthrenes.

A novel gold-catalyzed 6-exo-dig cycloisomerization of o-propargylbiaryls has been developed that provides ready access to functionalized phenanthrenes in largely good to excellent yields. Notable features of this method are readily available starting materials, mild reaction conditions, and broad substrate scope.

Flexible and practical synthesis of anthracenes through gold-catalyzed cyclization of o-alkynyldiarylmethanes.

A concise gold-catalyzed method for the preparation of anthracenes from o-alkynyldiarylmethanes has been developed. Under mild reaction conditions, versatile anthracene derivatives were formed in moderate to good yields. The high flexibility, broad substrate scope, and mild nature of this reaction render it a viable alternative for the synthesis of anthracenes.

Gene expression profiles of two intraspecific Larix lines and their reciprocal hybrids.

Heterosis has been widely explored in Larix breeding for more than a century, but the molecular mechanisms underlying this phenomenon remain elusive. In the present study, the genome-wide transcript profiles from two Larix genotypes and their reciprocal hybrids were analyzed using Arabidopsis 70-mer oligonucleotide microarrays. Despite sharing the same two parental lines, one of the hybrids showed obvious heterosis, while the other did not. In total, 1,171 genes were differentially expressed between the heterotic hybrid and its parents, of which 133 genes were nonadditive expression. The number of differentially expressed genes between the non-heterotic hybrid and the parents was 939, but only 54 of these genes were nonadditive expression. Further, gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) analyses indicated that most of these differentially expressed genes in the heterotic hybrid were associated with several important biological functions such as physiological processes, responses to stimulus, and starch and sucrose metabolism. The reliability of the microarray data was further validated by the Real-time quantitative RT-PCR. A high Pearson linear correlation coefficient value was detected (r = 0.759, P < 0.01). In conclusion, the gene expression profile in the Larix heterotic hybrid was significantly different from that obtained from the non-heterotic hybrid, and more nonadditive differentially expressed genes were detected in the heterotic hybrid, implying that nonadditive effects may be closely associated with the formation of heterosis in the intraspecific Larix hybridization.

DNA Methylation in Genomes of Several Annual Herbaceous and Woody Perennial Plants of Varying Ploidy as Detected by MSAP.

Polyploidization is known to accompany altered DNA methylation in higher plants, which plays an important role in gene expression regulation and maintaining genome stability. While the characteristics of DNA methylation in different polyploid plants are still to be elucidated; here, status of genomic DNA methylation in a series of diploid, triploid, and tetraploid annual herbaceous plants (watermelon and Salvia) and woody perennials (pear, Poplar, and loquat) were explored by methylation-specific amplified polymorphism analysis. The results indicated that levels of DNA methylation in triploid watermelon and Salvia were lower than their diploid parents. In triploid Poplar and pear, higher levels of DNA methylation were detected, and no significant difference was observed between triploid and tetraploid in all tested materials. Further data analysis suggested that about half of the total detected sites underwent changes of DNA methylation patterns in triploid watermelons and Salvia, as well as an obvious trend towards demethylation. However, the changes of DNA methylation patterns in three triploid woody perennials were only 17.54-33.40%. This implied that the characteristics of DNA methylation are significantly different during the polyploidization of different plant species. Furthermore, the results suggested that the level of DNA methylation was nonlinearly related to the ploidy level, and triploid plants displayed more interesting DNA methylation status. The characteristics and possible functions of DNA methylation in different ploidy series are further discussed.

TGF-beta1 immunohistochemistry and promoter methylation in chronic renal failure rats treated with Uremic Clearance Granules.

The aim of the study was the explain the mechanism related to therapeutic effects of Uremic Clearance Granules (Niaoduqing Keli in Chinese) on adenine-induced Chronic Renal Failure in rats. Thirty 8-week-old male Wistar rats were selected and randomly divided in to 3 groups: Normal Control Group (NCG)consisted of 10 rats, Chronic Renal Failure Pathological Control Group (PCG) 10 rats, and Uremic Clearance Granules Treatment Group (UCG) 10 rats. Each rat in PCG and UCG was fed with adenine-enriched diets, containing 10 g adenine per kg food for 6 weeks. After fed with adenine, each rat in UCG was administered orally with 2 ml solution of Uremic Clearance Granules for 6 weeks. The concentration of Uremic Clearance Granules solution was 0.42 g/ml which was 10 times of human. On days 42 and 84, the serum levels of creatinine, Blood Urea Nitrogen and homocysteine were determined. The methylation of TGFbeta1 promoter was tested by methylation-specific PCR. TGF-beta1 mRNA and protein expression in rat renal cortex were analyzed by real-time RT-PCR and Immunohistochemistry. (1) Experimented on model of Chronic Renal Failure in rats, the preparation was proved to be able to reduce serum creatinine, Blood Urea Nitrogen, and homocysteine (p<0.05), improve renal function. (2) The expression of TGF-beta1 in mRNA and protein level were down-regulated. (3) TGF-beta1 promoter was demethylated at some loci in PCG, and was recovered in UCG. After treatment with Uremic Clearance Granules, the Chronic Renal Failure Wistar rat's kidney function was recovered. The recovery may be result of the remethylation of TGF-beta1 promoter and then lead to TGF-beta1 be transcripted and translated normally. The experimental study explain the molecular mechanism by which Uremic Clearance Granules treat Chronic Renal Failure.

[Analysis of the level and pattern of genomic DNA methylation in different ploidy watermelons by MSAP (Citrullus lanatus)].

DNA methylation is one of the major epigenetic modifications. It is very important to the regulation of gene expression. In present study, an autoploidy series (2x, 3x and 4x) in watermelon (Citrullus lanatus) was constructed and MSAP (Methylation-Sensitive Amplification Polymorphism) analysis was conducted to elucidate the level and pattern of DNA methylation at CCGG sites in different ploidy watermelons. Totally, 1883 genetic loci were produced by 23 pairs of selective primers, of which 647, 655 and 581 sites were detected in diploid, autotriploid and autotetraploid, respectively. The methylation sites were 181, 150 and 159, and the corresponding total methylation ratios were 28.0%, 22.9% and 27.4% in 2x, 3x and 4x, respectively, of which the fully methylation sites were 121, 80 and 82, and the corresponding fully methylation ratios were 18.7%, 12.2% and 14.1%. Further analysis of the pattern of DNA methylation suggested that compared 4x with 2x, about half of detected sites (54.4%) shown changes of DNA methylation patterns. Similarly, compared 4x with 3x, 45.4% sites also shown changes of DNA methylation patterns. Moreover, the trend of DNA methylation adjustment mainly involved increase of DNA methylation levels in 4x. However, compared 3x with 2x or 4x, although the changes of DNA methylation pattern also widely occurred, which involved 41.6% (compared 3x with 2x) and 45.4% (compared 3x with 4x) sites, respectively, the trend of DNA methylation adjustment mainly involved decrease of DNA methylation levels in 3x. All these results indicated that DNA methylation events were widely existed in different ploidy watermelons. However, not only based on the total DNA methylation ratio or fully DNA methylation ratio, the results both implied that the DNA methylation levels were not closely associated with the autopolyploidy level in watermelon. Autotriploid watermelon shows obvious low level of DNA methylation. Analysis of DNA methylation patterns also suggested that the adjustment of DNA methylation patterns in autotriploid mainly involved demethylation events, implying the unusual characteristic of DNA methylation status in 3x watermelon. The present results are valuable to further explore the nature of triploid vigor and autopolyploidizaion in watermelon from the view of epigenetics.

Characters of DNA constitution in the rye B chromosome.

We have used chromosome microdissection and microcloning to construct a DNA library of the entire B chromosome (B) of rye. New rye B-specific sequences have been screened from this pool, blasted with other sequences and analyzed to elucidate the characters of DNA constitution and the possible pathway of the origin of the rye B chromosome. We report the discovery of a new sequence that is specific to the rye B centromere.

[Analysis on genetic diversity of different Salvia miltiorrhiza geographical populations in China].

OBJECTIVE: To research on genetic diversity of different Salvia miltiorrhiza geographical populations in China. METHOD: The genetic diversity of 27 S. miltiorrhiza geographical populations from ten provinces in China was estimated using amplified fragment length polymorphism (AFLP) markers. The data of amplified bands were analyzed by the software POPGENE and SPSS. RESULT: The ten primers employed produced a total of 528 discernable and reproduceable amplified fragments. There were 476 polymorphic brands. The percentage of polymorphic bands with in different populations was 90.15%. Genetic diversity analysis showed that Neis gene diversity (He) was 0.261 2 and Shannon's genetic diversity index (1) was 0.403 3. The coefficient of gene similarity was 0.504 0-0.789 0 between populations. The cluster map including all samples were obtained by UPGMA. In the map, there were seven cluster groups and one individual outside the groups. CONCLUSION: The genetic diversity with in different geographical population of S. miltiorrhiza in China is plentiful.

[Multicolor FISH analysis of rDNA and telomere on spin-ach].

In this study, multicolor FISH analysis on metaphase chromosomes of spinach with biotin-labeled 25S rDNA, DIG-labeled telomere sequences and biotin-labeled and DIG-labeled 5S rDNA was performed. There were six 25S rDNA loci, which were located on the satellites of the third, the fifth and the sixth chromosomes, four 5S rDNA loci, which were located on the long arms of the third and the fifth chromosomes. The telomere loci were located on the end of the sixth chromosome and also on both the end and centromeric regions of other chromosomes. This study is an important complement to both traditional karyotype analysis and FISH karyotype analysis in spinach.

[Studies on cytogeography of Pinellia ternata poliploid complex].

OBJECTIVE: In order to clarify the genetic background of Pinellia ternata germplasm resources in China, the chromosomal constitution and cytogeographical distribution of P. ternata were investigated in 27 different populations among 16 provinces and regions in China systematically. METHOD: Cytological and cytogeographical methods were used in the study. RESULT: P. ternata in China is a polyploid complex, which contains septuploid (2n = 7x = 91) , octoploid (2n = 8x = 104) , nonuploid (2n = 9x = 117) and decaploid (2n = 10x = 130). Meanwhile the aneuploid series (2n = 92, 103, 105, 115) of a minority of P. ternata were also found. CONCLUSION: The genetic differentiation and the phenomenon of ploidy miscellany commonly exist in the species of P. ternata in China, both for natural populations and cultivated populations. Toxicity and chemical components of different ploidy P. ternata should be clarified before the superior multiploid is selected for normalized plantation of the plant.

Preparation and analysis of cSNP chip on hepatocellular carcinoma-related genes.

BACKGROUND: The understanding of cSNPs of cancer-related genes harboring in high frequency loss regions of tumor chromosomes can advance the disclosure of genetic and variant mechanisms of tumorigenesis, and the investigation of cancer susceptibility. In preparing a gene chip for detecting polymorphisms on coding region of genes in hepatocellular carcinoma tissues, some cSNPs are of interest for their potential links with phenotype. METHODS: The genes harboring in loss regions with high frequency of hepatocellular carcinoma (HCC) were selected, the related information of cSNP sequences was obtained from the SNP database (dbSNP) of the National Center for Biotechnology Information (NCBI). Then appropriate primers and oligonucleotide probes were designed according to the SNP sites, and a gene chip for the detection of SNPs was constructed. The chip included 48 cSNPs of 25 hepatocellular carcinoma-related genes. The PCR products labeled by Dig-dUTP were hybridized with the cSNP chip. RESULTS: The sensitivity, influence by probe concentration, and reiteration of the chip were detected, with a high sensitivity of 6X10(-3) ng/mul. The signal of hybridization was reduced with a lower concentration of probe. Seven polymorphisms of caspase 9 (rs2308941)C-->T and DOK2(rs2242241) T-->G, 6 of polymorphisms of EGFL3 (rs947345)A -->G, caspase 9 ( rs2308938) C-->G and PHGDH(rs1801955)T-->A, 5 of polymorphisms of E2F2(rs3218170) G-->A,4 of polymorphisms of MUTYH(rs1140507)T-->C and BNIP3L(rs1055806)G-->T, and 1 of polymorphism of TNFRSF1B (rs1061622)T-->G were detected by the chip in the tissues of 10 HCC. Samples of caspase 9 (rs2308941G) and (rs2308941A) were verified by PCR-SSCP and sequencing. CONCLUSION: The cSNP chip of hepatocellular carcinoma-related genes can accelerate the discovery of polymorphic markers on hepatocellular carcinoma.

[Identification of molecular markers linked to the fertility restoring gene for the CMS Capsicum annuum L].

Bulked segregant analysis method was used to identify random amplified polymorphic DNA (RAPD) markers linked to the fertility restoring gene for the cytoplasmic male sterility (CMS) capsicum annum L. Totally 336 random primers were screened on the DNA samples of restorer and sterile bulks. Primer S418 produced a special band in restorer line. It was about 3000 bp, including two fragments 1515 bp and 1162 bp. Fluorescence in situ hybridization(FISH) indicated the fragment of 1515 bp only existed in restorer line.It was designed to S418(1515). Analysis of the sequence indicated S418(1515) was unknown before. The homology of blastn was less than 40%, however the homology of tBlastx indicated this sequence was high homologous with the part sequences of rice which were distributed on 2,4,7,10 chromosomes. It suggested this sequence might have the similar function with them. This result offered a good foundation to research the molecular mechanism of fertility restoration for CMS capsicum. Based on the sequence, special primers were designed to transform the RAPD marker to PCR marker. The result indicated that these primers could be used to screen the restorer lines from a large quantitive of candidate lines.

[Investigation on the molecular mechanisms of anti-hepatocarcinoma herbs of traditional Chinese medicine by cell cycle microarray].

OBJECTIVE: To design DNA microarray and investigate the molecular anti-tumor mechanism of herbs of traditional Chinese medicine. METHOD: cDNA microarrays consisting of 56 probes representing 24 human cell cycle genes were constructed, Four anti-hepatocarcinoma herbs including Radix Linderae, Hebra Artemisiae Annuae, Radix Amebiae, Radix Astragli, were chosen. Effects of herbs on SMMC-7721 cell cycle were observed by flow cytometry assay. Effects of herbs on cell cycle gene expression in SMMC-7721 cells were analyzed by comparing hybridization of Dig-Labeled cDNAs from herb-treated cells and cDNAs from untreated cells. RESULT: Expressions of cell cycle geneswere changed in different degrees after herbs treated. Some genes were down-regulated and some genes were up-regulated. The changes in gene expression agreed with the results of flow cytometry assay. CONCLUSION: The results suggest that these herbs may have effects on cell cycle and DNA damage checkpoint genes which may be the mechanism of the herbs, and DNA microarray can be used to investigate the biological function of extracts of traditional Chinese medicine.

The molecular characterization of maize B chromosome specific AFLPs.

The origin and evolution of B chromosomes could be explained by the specific DNA sequence on them. But the specific sequences known were quite limited. To investigate maize B chromosome sqicific DNA sequeces, maize genomes with and without B chromosomes were analyzed by AFLP. Only 5 markers were found specific to genomes with B chromosomes among about 2000 AFLP markers. Southern hybridization and sequence analysis revealed that only the sequence of M8-2D was a B chromosome specific sequence. This sequence contained the telomeric repeat unit AGG