OBJECTIVETo identify Menthae Haplocalycis Herba and its closely related species using DNA barcoding technique.

METHODTotal genomic DNA was isolated from Mentha canadensis and its closely related species. Nuclear DNA ITS2 sequences were amplified, and purified PCR products were sequenced. Sequence assembly and consensus sequence generation were performed using the CodonCode Aligner V3.0. The Kimura 2-Parameter (K2P) distances were calculated using software MEGA 5.0. Identification analyses were performed using BLAST1, Nearest Distance and neighbor-joining (NJ) methods.

RESULTThe intra-specific genetic distances of M. canadensis were ranged from 0 to 0.006, which were lower than inter-specific genetic distances between M. canadensis and its closely related species (0.071-0.231). All the three methods showed that ITS2 could discriminate M. canadensis from its closely related species correctly.

CONCLUSIONThe ITS2 region is an efficient barcode for identification of Menthae Haplocalycis Herba, which provides a scientific basis for fast and accurate identification of the herb.

DNA Barcoding, Taxonomic ; methods ; DNA, Ribosomal Spacer ; genetics ; Plants, Medicinal ; classification ; genetics ; Sequence Analysis, DNA ; methods

A new version of DNA walks, where nucleotides are regarded unequal in their contribution to a walk is introduced, which allows us to study thoroughly the "fine structure" of nucleotide sequences. The approach is based on the assumption that nucleotides have an inner abstract characteristic, the determinative degree, which reflects genetic code phenomenological properties and is adjusted to nucleotides physical properties. We consider each codon position independently, which gives three separate walks characterized by different angles and lengths, and that such an object is called triander which reflects the "strength" of branch. A general method for identifying DNA sequence "by triander" which can be treated as a unique "genogram" (or "gene passport") is proposed. The two- and three-dimensional trianders are considered. The difference of sequences fine structure in genes and the intergenic space is shown. A clear triplet signal in coding sequences was found which is absent in the intergenic space and is independent from the sequence length. This paper presents the topological classification of trianders which can allow us to provide a detailed working out signatures of functionally different genomic regions.
Algorithms ; Base Sequence ; Chromosome Mapping ; methods ; Codon ; genetics ; DNA ; genetics ; Molecular Sequence Data ; Nucleotides ; genetics ; Sequence Analysis, DNA ; methods

Traditional DNA sequence analysis is based on sequence alignment, while a new DNA visual sequence analysis is proposed in this paper. Based on S. Wolfram's cellular automation theory, the method transfers one-dimensional DNA sequence into two-demensional visual image. Applying this method to SARS DNA sequence analysis, a characteristic of SARS-CoV differing from non-SARS is discovered. Compared with all known coronaviruses' images, It is found that this is a unique characteristic of SARS virus, and it is helpful to clinical identification of SARS.
Algorithms ; SARS Virus ; genetics ; Sequence Analysis, DNA ; methods

Objective To evaluate the efficiency of REPLI-g® Single Cell Kit for sample DNA amplification, and explore its application value in forensic trace DNA amplification. Methods Three DNA extraction kits were selected to extract DNA from peripheral blood of 10 unrelated individuals. The DNA yield and purity of the three DNA extraction kits were compared. According to the results of comparison, one DNA sample was selected to concentrate and dilute, then used as the initial sample of whole genome amplification （WGA）. REPLI-g® Single Cell Kit was used to amplify the initial sample at the whole genome level. The amplification yield and amplification times were calculated, and the distribution of DNA fragments was detected by agarose gel electrophoresis. Goldeneye® DNA ID System 20A Kit was used to perform the STR typing of the initial sample and DNA samples amplified at the whole genome level to evaluate the performance of REPLI-g® Single Cell Kit in trace DNA amplication in terms of purity and yield as well as the success rate of STR typing. Results After comparison, one DNA sample was selected from QIAsymphony® DNA Investigator® Kit extracts to concentrate and dilute as the initial sample of WGA. After amplifying the whole genome of a series of initial samples by REPLI-g® Single Cell Kit, the lowest average of amplification yield reached 8.77×103 ng, while the average of the corresponding amplification times reached 1.40×106. DNA fragments were large and concentrated. The STR typing success rate of WGA samples became lower with the decrease of initial samples used, but when the amount of samples was lower than 0.5 ng, the STR typing success rate of samples after DNA WGA was higher than that of samples without DNA WGA. Conclusion REPLI-g® Single Cell Kit can increase the yield of template DNA. Especially for trace DNA, the STR typing success rate can be improved to a certain extent.
DNA ; DNA Fingerprinting ; Humans ; Microsatellite Repeats ; Nucleic Acid Amplification Techniques/standards* ; Sequence Analysis, DNA/methods*

Base Sequence ; DNA ; chemistry ; DNA-Directed DNA Polymerase ; metabolism ; Fluorescent Dyes ; chemistry ; Humans ; Molecular Sequence Data ; Nanostructures ; Polymerase Chain Reaction ; methods ; Sequence Analysis, DNA ; methods

OBJECTIVETo establish a new method for the identification of Schisandra sphenanthera and S. chinensis.

METHODRandom amplified polymorphic DNA-Sequence characterized applied region (RAPD-SCAR) method was applied to screen primers.

RESULTScreening from 100 primers, only 2 random primers, which can be used to identify S. sphenanthera and S. chinensis accurately with a good reproducibility. It worked to fit them into sequence characterized applied region.

CONCLUSIONRAPD-SCAR can be used to identify S. sphenanthera and S. chinensis accurately.

Base Sequence ; Molecular Sequence Data ; Polymerase Chain Reaction ; methods ; Random Amplified Polymorphic DNA Technique ; Schisandra ; genetics ; Sequence Analysis, DNA

No abstract available.
DNA, Neoplasm/genetics ; High-Throughput Nucleotide Sequencing/*methods ; Humans ; Sequence Analysis, DNA/methods ; Urologic Neoplasms/*genetics

Phylogenetic relationship between Paecilomyces hepiali and Cordyceps sinensis was studied by analyzing the sequence of rDNA-ITS. The samples of C. sinensis were collected from Hualong County in Qinghai Province and Kangding County in Sichuan Province in May and June, respectively. The rDNA-ITS fragments were obtained by PCR amplification with the template genomic DNA of the fresh stroma or caterpillar body of the collected samples and the cultured mycelium of P. hepiali, with the universal fungal primers ITS1/ITS4. The amplified fragments were cloned into pMD18-T Vector and sequenced. Phylogenetic analysis was performed with these sequences and those from GenBank. The result showed that all of the 46 clones randomly chosen from the amplification of C. sinensis shared identical or almost identical rDNA-ITS regions and had over 99% identity with some rDNA-ITS sequences of Hirsutella sinensis and C. sinensis registered in GenBank, but all of them had only about 72% identity with that of P. hepiali. Two pairs of specific primers were designed based on the rDNA-ITS sequence of P. hepiali, then PCR and Nest-PCR were performed with the template genomic DNA of the stroma or caterpillar body of C. sinensis samples mentioned above. The apparent bands amplified by Nest-PCR were obtained from all of the samples, and the sequences showed 100% identity with the rDNA-ITS sequence of P. hepiali. In addition, another pair of specific primers were designed based on the rDNA-ITS sequence registered in GenBank as the marker of C. sinensis (accession no. AB067740) but the latter only shared 87.3% identity with that of H. sinensis (accession no. AJ309353). This pair of primers was used to amplify the C. sinensis samples by PCR, and the amplified sequence showed 100% identity with that of AB067740. The result indicated that H. sinensis is the main body of C. sinensis, while some other endoparasitic fungi such as P. hepiali commonly exist in the natural C. sinensis.
Base Sequence ; Cordyceps ; classification ; genetics ; DNA, Fungal ; genetics ; DNA, Ribosomal Spacer ; genetics ; Molecular Sequence Data ; Paecilomyces ; classification ; genetics ; Phylogeny ; Polymerase Chain Reaction ; methods ; Sequence Alignment ; Sequence Analysis, DNA

The energy of interaction between complementary nucleotides in promoter sequences of E. coli was calculated and visualized. The graphic method for presentation of energy properties of promoter sequences was elaborated on. Data obtained indicated that energy distribution through the length of promoter sequence results in picture with minima at -35, -8 and +7 regions corresponding to areas with elevated AT (adenine-thymine) content. The most important difference from the random sequences area is related to -8. Four promoter groups and their energy properties were revealed. The promoters with minimal and maximal energy of interaction between complementary nucleotides have low strengths, the strongest promoters correspond to promoter clusters characterized by intermediate energy values.
AT Rich Sequence ; genetics ; Base Sequence ; Chromosome Mapping ; methods ; DNA, Bacterial ; genetics ; Escherichia coli ; genetics ; Molecular Sequence Data ; Promoter Regions, Genetic ; genetics ; Sequence Analysis, DNA ; methods ; Transcription, Genetic ; genetics

OBJECTIVETo analyze the possible reason for HLA-C allele dropout in routine sequence-based typing (SBT) and improve the accuracy of HLA-C SBT test.

METHODSA total of 620 randomly selected samples from healthy voluntary blood donors in Shenzhen were typed at HLA-C locus by sequence-based typing using the AlleleSEQR HLA-C plus sequence-based typing kit. Samples with no full match result were subjected to cloning and haplotype sequencing of the full-length HLA-C gene. If no novel mutations were found, samples were then retyped, using our self-designed PCR primer pair and PCR conditions replacing the AlleleSEQR HLA-C PCR reagents in the PCR set-up procedure so as to analyze the potential reasons for causing abnormal SBT result.

RESULTSIn the 620 samples typed at HLA-C locus using the AlleleSEQR HLA-C SBT commercial kit, 5 samples with no full match result were identified. The closest genotype showed one nucleotide mismatch with many different allele groups at different nucleotide position. Based on the PCR-SBT nucleotide sequence, heterozygous nucleotides were determined only in exon 4, whereas the nucleotides in exon 2 and 3 were all homozygotes. The results showed that HLA-Cw*0706 allele dropout existed in all the 5 samples with abnormal SBT results initially identified by AlleleSEQR HLA-C SBT kit, no novel mutation was found.

CONCLUSIONThe results indicate that the PCR primer pair incompatible with DNA template may result in allele dropout in HLA-C SBT test. Based on the characterization of HLA-C full-length, it is essential to develop HLA-C SBT kit suitable for Chinese population in the future.

Alleles ; Amino Acid Sequence ; Base Sequence ; DNA Fingerprinting ; methods ; standards ; HLA-C Antigens ; genetics ; Humans ; Molecular Sequence Data ; Mutation ; Sequence Analysis, DNA ; methods ; standards