Sequence Analysis of Mitochondrial DNA D-loop Region in Xinjiang Goose

[Objective] The sequences of mitochondrial DNA D-loop region of Xinjiang Goose with three different colors of plumage were analyzed in order to study the genetic diversity of Xinjiang Goose, as well as the phylogeny and evolution. [Method] Ten geese were selected randomly from the core populations of grey-, mosaic- and white-plumaged Xinjiang Goose respectively with a total number of thirty as experi- mental materials, of which the blood samples were collected from the largest vein under the wing （brachial vein） for DNA extraction. Sequences of mitochondrial DNA D-loop regions were determined using DNA sequencing technology to analyze the polymorphism. In addition, the genetic distances among different populations were estimated through the comparison with the reference sequences. [Resull] The con- tents of A, G, C and T nucleotides in the D-loop region of Xinjiang Goose were 28.85%, 17.05%, 25.38% and 28.72%, respectively. The average haplotype diversity and nucleotide diversity of Xinjiang Goose were 0.583 and 0.056. Xinjiang Goose and Greylag Goose were clustered into the same group. [Conclusion] The results showed that Xinjiang Geese with three different colors of plumage all descend from Greylag Goose （Anser anser）.

Gene cloning and sequence analysis of the cold-adapted chaperones DnaK and DnaJ from deep-sea psychrotrophic bacterium Pseudoalteromonas sp. SM9913

Pseudoalteromonas sp. SM9913 is a phychrotmphic bacterium isolated from the deep-sea sediment. The genes encoding chaperones DnaJ and DnaK of P. sp. SM9913 were cloned by normal PCR and TAIL - PCR （GenBank accession Nos DQ640312, DQ504163 ）. The chaperones DnaJ and DnaK from the strain SM9913 contain such conserved domains as those of many other bacteria, and show some cold-adapted characteristics in their structures when compared with those from psychro-, meso-and themophilic bacteria. It is indicated that chaperones DnaJ and DnaK of P. sp. SM9913 may be adapted to low temperature in deep-sea and function well in assisting folding, assembling and translocation of proteins at low temperature. This research lays a foundation for the further study on the cold-adapted mechanism of chaperones DnaJ and DnaK of cold-adapted microorganisms.

Cloning and Sequence Analysis of 16S rRNA and COI Gene in Mitochondrial DNA of Scortum barcoo

[Objective] The aim was to provide molecular biological basis for the researches on the genetic resources,genetic relationship among species and phyletic evolution of S.barcoo.[Method] PCR amplification and sequencing were used to study the 16S rRNA and COI gene fragments.[Result] As for 16S rRNA gene fragments,nucleotide sequences of 791 bp were obtained,and the A,T,G and C contents in this fragment were 31.6%,21.4%,20.4% and 26.7%respectively.As for the COI gene fragments,the size was 631 bp and the A,T,G And C contents were 27.7%,23.6%,29.8% and 18.9% respectively.Among these two gene fragments,the content of GC was lower than AT,and AT/GC of these two fragments was 1.13 and 1.05 respectively.[Conclusion] The genetic characteristics of gene fragments of 16S rRNA and COI of S.barcoo suggested that the variation in the same species was relatively low.The sequences of 16S rRNA gene in three samples the same,while the sequences of COI gene was also the same,indicating that these two gene of S.barcoo were conservative.

Sequence Analysis of ITS Region of rDNA of Alternaria Nees. from Some Areas of China

[Objective] The study aimed to identify Alternaria Nees from some areas of China at molecular level by analyzing the rDNA ITS sequence. [ Method ] The DNA sequences coding for the 5.8S rDNA and the flanking internal transcribed spacers （ ITS1 and ITS2） were amplified by PCR with universal primers ITS4 and ITS5 and subsequently sequenced for 34 Alternaria isolates from different areas of China. [Result] Sequences analysis showed that 5.8S rDNA was 159 bp and no variation in tested 34 isolates. There had variables sites in ITS. The isolates that had same sequences as A. tenuissima or A. alternata all put up eurytopicity to area and host. The variables sites of the isolates showed the diver- sity of Alternaria in the hosts of Oleaceae, Rosaceae and Solanaceae. At the same time that ITS could not clearly separated the isolates was indicated. The results indicated that the phylogenetic relationship were not closely related to the geographical origin and hosts of these isolates. [ Conclusion] The sequence analysis of ITS region could provide theory basis for the identification of Alternaria Nees..

Construction of Midgut Tissue-Specific cDNA Library of Bombyx mandarina M. and Isolation and Sequence Analysis of Serine Protease Gene Fragment

[Objective] The aim of the study is to construct cDNA library of midgut tissue of wild silkworm and isolate the serine protease gene. [Method] The midgut tissue-specific cDNA library of wild silkworm was constructed via cDNA Library Construction Kit (TaKaRa), then the serine protease gene was cloned via sequencing of the yielded cDNA library. [Result] The titer of cDNA library reached 6.2×105 pfu/ml, average insert size was about 1.2 kb. The serine protease gene cDNA fragment was obtained from colony sequencing (Accession No: EU672968). The nucleotide sequence of the cloned 854 bp fragment encodes 284 amino acid residues. Homology analyses showed some homology between putative amino acid sequence of the cloned fragment and amino acid sequences of serine proteases from other ten insects. [Conclusion] The results may avail to reveal the resistance of silkworm and wild silkworm to exotic intrusion.

Cloning and Sequence Analysis of Interleukin 10 (IL-10) Full-length cDNA from Cyprinus carpio L.

[Objective] This study aimed to obtain IL-10 (interleukin 10) full-length cDNA of common carp (Cyprinus carpio L.) and conduct the sequence analysis. [Method] The differentially expressed cDNA fragment was obtained by DD-RTPCR (differential display RT-PCR). The cDNA library of peripheral blood leukocytes which were separated from common carp and stimulated by mitogen was screened with a probe labeled with DIG (digoxigenin). The IL-10 full-length cDNA was cloned from 0.8×104 pfu of recombinant phages, and the sequence analysis and homology comparison were carried out. [Result] Sequence analysis indicated that the IL-10 full-length cDNA of common carp was 1 117 bp long, containing a 55 bp 5’-UTR, a 522 bp 3’-UTR, and a 540 bp open reading frame(ORF) encoding 179 amino acids. In addition, there were three mRNA instability motifs (ATTTA) in the 3’-untranslated region. The deduced protein sequence shared typical sequence features of the IL-10 family. Homology comparison indicated that the obtained sequence shared 89.1% homology with the carp IL-10 gene from GenBank. [Conclusion] This study laid foundation for further study of the expression manner, functional characteristic and regulation mechanism of IL-10 in vivo and the interaction mechanism in the inflammatory reaction and immune response.

Identification and rDNA-ITS Sequence Analysis of a New Anthracnose Pathogen of Dracaena fragrans in Yunnan Province

In this study, identification and rDNA-ITS sequence analysis of an anthracnose pathogen on Dracaena fragrans were carried out. [Method] D. fra-grans leaves with lesions were used as experimental materials to isolate anthrac-nose pathogen. Morphological observation, rDNA-ITS amplification and sequence analysis were performed to identify the pathogen strain. [Result] Caonidia of the iso-lated anthracnose pathogen were straight or curved, el iptic to crescent, with 2-5 oil droplets, 7.5-20 × 4.5-5 μm. According to molecular phylogenetic analysis, the iso-lated pathogen strain was identified as a new species, which was named Col-letotrichum dracaena-fragrantis sp. nov. [Conclusion] This study provided theoretical basis for the prevention and control of anthracnose.

cDNA Cloning and Sequence Analysis of ADH Gene in Delia antiqua

[Objective] This study aims to conduct cloning and sequence analysis of ADH gene in D. Antiqua. [Method] Full-length cDNA of ADH gene in D. antiqua was cloned by using RACE technology （GenBank access number： JQ666006）. Analysis of the homology, characteristics and functional domains of ADH sequence and the phy- Iogenetic relationship to other dipteran ADH were conducted. [Result] The full length of ADH cDNA is 1 088 bp containing a 771 bp of ORF, encoding 256 amino acids, with a calculated relative molecular weight of 30.80 kDa and a theoretical isoelectric point of 8.22. The deduced amino acid sequence shares the highest homology with Glossina morsitans morsitans based on homological analysis and phylogenetic analysis. [Conclusion] This study provides basis for further research of ADH gene.

Molecular Cloning and cDNA Sequence Analysis of Two New Lepidopteran OR83b Orthologue Chemoreceptors

The aim of this study was to isolate the full-length cDNA sequences of an unusually highly conserved olfactory receptor （orthologue to the Drosophila melanogaster DOR83b） from the antennae of Spodoptera exigua and S. litura by using reverse transcription-polymerase chain reaction （RT-PCR） and rapid amplification of cDNA ends （RACE） methods. Bioinformatics methods were used to further analyze the cDNA sequences and putative amino acid sequences. The two full-length cDNA sequences from olfactory receptor （OR） of male S. exigua and S. litura were named as SexiOR2 and SlitOR2, respectively. SexiOR2 and SlitOR2 consisted of nucleotide sequence of 1 906 and 2 483 bp, respectively, and both with deduced amino acid sequences of 473 residues. The sequence analysis indicated that the deduced amino acid sequences of the cDNA shared the high homologies with OR83b orthologue chemoreceptor sequences from previously reported moths, implying that the cDNA sequences were of OR83b orthologue chemoreceptor genes.

Sequence analysis of the ITS region and 5.8S rDNA of Porphyra haitanensis

The sequences of the ITS(internal transcribed spacer) and 5.8S rDNA of three cultivated strains of Porphyra haitanensis thalli(NB,PT and ST) were amplified,sequenced and analyzed.In addition,the phylogenic relationships of the sequences identified in this study with those of other Porphyra retrieved from GenBank were evaluated.The results are as follows:the sequences of the ITS and 5.8S rDNA were essentially identical among the three strains.The sequences of ITS1 were 331 bp to 334 bp,while those of the 5.8S rDNA were 158 bp and the sequences of ITS2 ranged from 673 bp to 681 bp.The sequences of the ITS had a high level of homology(up to 99.5%) with that of P.haitanensis(DQ662228) retrieved from GenBank,but were only approximately 50% homologous with those of other species of Porphyra.The results obtained when a phylogenetic tree was constructed coincided with the results of the homology analysis.These results suggest that the three cultivated strains of P.haitanensis evolved conservatively and that the ITS showed evolutionary consistency.However,the sequences of the ITS and 5.8S rDNA of different Porphyra species showed great variations.Therefore,the relationship of Porphyra interspecies phyletic evolution could be judged,which provides the proof for Porphyra identification study.However,proper classifications of the subspecies and the populations of Porphyra should be determined through the use of other molecular techniques to determine the genetic variability and rational phylogenetic relationships.

Cloning and Sequence Analysis of Interferon γ-2β Full-length cDNA in Cyprinus carpio L.

[Objective] The research aimed to carry out the cloning, identification and sequence analysis of full-length cDNA of carp interferon γ-2β （IFNγ-2β）. [Method] The cDNA library of peripheral blood leucocytes which were separated from carp and stimulated with mitogen was screened by a probe labeled with DIG. The IFNγ- 2β EST sequence was picked out from the constructed cDNA library of peripheral blood leucocyte, and the full length of carp interferon γ-2β was cloned. In addition, the sequence analysis was carried out. [Result] Three positive clones were obtained. Sequence analysis indicated that the sequence had a 119 bp 5’-UTR and a 218 bp 3’-UTR, and the open reading frame （ORF）of this gene was 537 bp which putatively coded 178 amino acids and there were several instable motifs for mRNA （ATTTA） in the 3’-untranslated region. Its homology with IFN from GenBank was up to 97% . Analysis on protein sequence and structure showed that the predicted protein sequence was identified as an IFN family signature. [Conclusion] The research laid the foundation for further studying the expression manner, function characteristic and regulation mechanism of IFNγ-2β in vivo and the action mechanism in the inflammatory reaction, emergency reaction and immune response.

Study on the Detection of Telomerase Activity by Combining DNA Sequence Analysis with TRAP

Telomeric repeat amplification protocol (TRAP) is now a conventional assay for detecting telomerase activity. However, this method presents problems owing to tedious quantitation, radioisotopic handling. In order to alleviate these inconveniences, a novel telomerase DNA sequencing assay together with TRAP to detect human telomerase activity was developed. It was used to detect telomerase activity in Hela, HLF, MCF, K562, SMMC 7721 cells, Leukocytes and RNase pretreated or heat treated cells as control. Telomerase activity assayed by this method was positive when the number of K562 cells examined was 102,103, and 104. The telomerase activity depended on the number of K562 cells used in the assay. Telomerase activity of Rnase pretreated cells or heat treated cells, and human normal peripheral blood leukocyte(Leu) were negative. The result of this method was available within a few hours and was handled without radioisotope. Further studies should be taken to detect telomerase activity in quantitation.

Molecular Cloning and Sequence Analysis of the Toc33 cDNA in Brassica napus Line Cr3529

Two primers, designed according to the Arabidoposis thaliana Toc33 sequence, were used to amplify the full coding region of the Toc33 cDNAs in leaves of a chlorophyll-reduced (Cr) mutant Cr3529 and its wild type 3529, Brassica napus, by RT-PCR technique. The RT-PCR results showed that the fragment homologous to Toc33 was expressed in Cr3529 as well as 3529 seedlings. PCR fragments were inserted into the pMD18-T vector and transferred into E. coli, then two cDNA clones, BnToc33-c and BnToc33, were obtained. Sequence analysis showed that the two sequences were 894 bp and the nucleotide and the deduced amino acid sequences were highly homologous to those of A. thaliana. There were three diverged nucleotides between the Cr3529 and the 3529 Toc33 cDNAs, i.e., GGT/AGT, TTG/TTT, AGG/AGT, all of which belonged to missense mutation. The amino acid replacement ((Leu/Phe) caused by TTG/TTT mutation located in the membrane anchor domain may result in chlorophyll-reduced character in Cr3529.

Cloning and Sequence Analysis of cDNA Encoding MRJP3 of Apis cerana cerana

By screening the worker （Apis cerana cerana） heads cDNA library using a fragment of the mrjp3 gene of Apis cerana as probe, 120 positive clones were obtained. The clone containing A. cerana cerana MRJP3 （AccMRJP3） cDNA was selected. Based on the sequencing of the inserts of the positive clone, a sequence of AccMRJP3 cDNA which is 1 887 bp long including a poly （A） tail was obtained. The AccMRJP3 cDNA encompassed an open-reading frame （ORF） with 1 779 bp encoding 593 amino acids. The un-translated regions （UTR） of the 5′ end and 3′end are 46 bp and 160 bp in length, respectively. Similar to AmMRJP3 and AdMRJP3, the putative AccMRJP3 also has a repetitive region. The comparison of the repetitive region of AccMRJP3, AmMRJP3 and AdMRJP3 shows some differences between them.

A hybrid swarm population of Pinus densiflora × P. sylvestris inferred from sequence analysis of chloroplast DNA and morphological characters

To confirm a hybrid swarm population of Pinus densiflora × P. sylvestris in Jilin, China, we used needles and seeds from P. densiflora, P. sylvestris, and P. densiflora × P. sylvestris collected from natural stands or experimental stations to study whether shoot apex morphology of 4-year old seedlings can be correlated with the sequence of a chloroplast DNA simple sequence repeat marker （cpDNA SSRs）. Total genomic DNA was extracted and subjected to sequence analysis of the pine cpDNA SSR marker Pt15169. Results show that morphological characters from 4-year old seedlings did not correlate with sequence variants of this marker. Marker haplotypes from all P. sylvestris trees had a CTAT element that was absent from all sampled P. densiflora trees. However, both haplotype classes involving this insertion/deletion element were found in a P. densiflora × P. sylvestris population and its seedling progeny. It was concluded that the P. densiflora × P. sylvestris accessions sampled from Jilin, China resulted from bi-directional crosses, as evidenced by both species’ cpDNA haplotypes within the hybrid swarm population.

Molecular Cloning and Sequence Analysis of Chitin Synthase cDNA from Mamestra brassicae (L.) (Lepidoptera: Noctuidae) Cuticle

Chitin is the most widespread amino polysaccharide in nature. Chitin synthase （CHS） plays an important role in chitin formation in the cuticle and the peritrophic membrane （PM） lining the midgut. Total RNA was isolated from the cuticle of Mamestra brassicae （L.） fourth instar larva, cDNA sequence was cloned by RT-PCR and Rapid Amplification of cDNA Ends （RACE）. cDNA 5 220 bp in length, contained an open reading frame of 4 704 bp coding for a polypeptide of 1 567 amino acid residues with a predicted molecular weight of 178.3 ku and its pI was 6.42. The deduced amino acid sequence from Mi brassicae （L.） shared the high level of identity with chitin synthase sequences from other insects, especially lepidopteran insects, cDNA sequence has been deposited with GenBank under accession No. GQ281761

Intraspecific Phylogenetic Relationships of Caryopteris incana in the Tsushima Islands, Japan, Using DNA Sequence Analysis

Caryopteris incana is a perennial shrub distributed in the temperate zone of the East Asia. It is found in West Kyushu in Japan, where it is designated as an endangered species. Tsushima, Nagasaki, which experienced repeated connection and fragmentation between the Korean Peninsula and Japan, is an island on the route along which C. incana moved to Japan from continental Asia. We conducted field work and confirmed the genetic structure of populations using DNA sequence analysis to construct a detailed distribution map and clarify the intraspecific phylogenetic relationships of C. incana in Tsushima Island. We confirmed 72 populations in Tsushima. Using the leaves of individuals cultivated from seeds collected from each natural population, we analyzed the chloroplast and nuclear DNA sequence variations. Among the populations, sequence variations were confirmed in six regions of chloroplast DNA, and six haplotypes, including base substitutions, were distinguished. Two haplotypes were mainly divided at the border of the northern part of the southern island in Tsushima. One population in the northwestern part of the north island showed a haplotype derived from the southern part. This finding revealed that the distribution of C. incana had been artificially influenced. Several haplotypes were confirmed by sequence variations in the northern populations, but only one haplotype in the southern populations, suggesting that C. incana on the north island had separated early from the south island in Tsushima.

Mitochondrial DNA sequence analysis of two mouse hepatocaranoma cell lines

AIM: To study genetic difference of mitochondrial DMA (mtDNA) between two hepatocarcinoma cell lines (Hca-F and Hca-P) with diverse metastatic characteristics and the relationship between mtDNA changes in cancer cells and ttieir oncogenic phenotype. METHODS: Mitochondrial DMA D-loop, tRNAMet+Glu+Ile and ND3 gene fragments from the hepatocarcinoma cell lines with 1100,1126 and 534 bp in length respectively were analysed by PCR amplification and restriction fragment length polymorphism techniques. The D-loop 3′ end sequence of the hepatocarcinoma cell lines was determined by sequencing. RESULTS: No amplification fragment length polymorphism and restriction fragment length polymorphism were observed in tRNAMet+Glu+Ile, ND3 and D-loop of mitochondrial DNA of the hepatocarcinoma cells. Sequence differences between Hca-F and Hca-P were found in mtDNA D-loop. CONCLUSION: Deletion mutations of mitochondrial DNA restriction fragment may not play a significant role in carcinogenesis. Genetic difference of mtDNA D-loop between Hca-F and Hca-P, which may reflect the environmental and genetic influences during tumor progression, could be linked to their tumorigenic phenotypes.

A New Numerical Method for DNA Sequence Analysis Based on 8-Dimensional Vector Representation

Background: The multiple sequence alignment (MSA) algorithms are the traditional ways to compare and analyze DNA sequences. However, for large DNA sequences, these algorithms require a long time computationally. Objective: Here we will propose a new numerical method to characterize and compare DNA sequences quickly. Method: Based on a new 2-dimensional (2D) graphical representation of DNA sequences, we can obtain an 8-dimensional vector using two basic concepts of probability, the mean and the variance. Results: We perform similarity/dissimilarity analyses among two real DNA data sets, the coding sequences of the first exon of beta-globin gene of 11 species and 31 mammalian mitochondrial genomes, respectively. Conclusion: Our results are in agreement with the existing analyses in our literatures. We also compare our approach with other methods and find that ours is more effective.

Advances in microfluidic-based DNA methylation analysis

DNA methylation has been extensively investigated in recent years,not least because of its known relationship with various diseases.Progress in analytical methods can greatly increase the relevance of DNA methylation studies to both clinical medicine and scientific research.Microflu-idic chips are excellent carriers for molecular analysis,and their use can provide improvements from multiple aspects.On-chip molecular analysis has received extensive attention owing to its advantages of portability,high throughput,low cost,and high efficiency.In recent years,the use of novel microfluidic chips for DNA methylation analysis has been widely reported and has shown obvious superiority to conventional methods.In this review,wefirst focus on DNA methylation and its applications.Then,we discuss advanced microfluidic-based methods for DNA methylation analysis and describe the great progress that has been made in recent years.Finally,we summarize the advantages that microfluidic technology brings to DNA methylation analysis and describe several challenges and perspectives for on-chip DNA methylation analysis.This review should help researchers improve their understanding and make progress in developing microfluidic-based methods for DNA methylation analysis.