BACKGROUNDTo express in vitro the bovine enterokinase catalytic subunit (EKL) protein, which could be used in the future for the cleavage and purification of fusion proteins.

METHODSBovine enterokinase catalytic subunit cDNA was obtained by RT-PCR from duodenal mucosa of a bovine obtained at wholesale market, and then cloned into a pUCmT cloning vector and sequenced. The desired gene fragment was inserted into a pET39b expression plasmid and the recombinant vector pET39b-EKL was transformed into E. coli BL21 (DE3). Protein expression was induced using IPTG. The recombinant DsbA-EKL was purified with His.Tag affinity chromatography, and it bioactivity was analyzed.

RESULTSCompared with the sequence deposited in GenBank, the sequence of the EKL gene cloned in the present study is correct. It was also confirmed that the nucleotide sequence of expression plasmid pET39b-EKL was correct at the conjunction site between the recombinant DNA 5' terminal multi-cloning site and the recombinant fragment. SDS-PAGE analysis indicated that the target product was about 65 kDa and represented 28% of total cell protein. Purified recombinant protein was obtained by metal chelating chromatography using Ni-IDA resin. After desalting and changing the buffer, the crude kinase was incubated at 21 degrees C overnight and shown to have a high autocatalytic cleavage activity.

CONCLUSIONSThe EKL gene from Chinese bovine has been cloned successfully and expressed. This investigation has layed the foundation for future enterokinase activity research and for further large-scale application of expression products.

Animals ; Catalytic Domain ; genetics ; Cattle ; Cloning, Organism ; DNA, Complementary ; Enteropeptidase ; analysis ; genetics ; Recombinant Proteins

OBJECTIVETo examine the global effects of Mycobacterium tuberculosis (M. tuberculosis) infection on macrophages.

METHODSThe gene expression profiling of macrophage U937, in response to infection with M. tuberculosis H(37)R(a), was monitored using a high-density cDNA microarray.

RESULTSM. tuberculosis infection caused 463 differentially expressed genes, of which 366 genes are known genes registered in the Gene Bank. These genes function in various cellular processes including intracellular signalling, cytoskeletal rearrangement, apoptosis, transcriptional regulation, cell surface receptors, cell-mediated immunity as well as a variety of cellular metabolic pathways, and may play key roles in M. tuberculosis infection and intracellular survival.

CONCLUSIONSM. tuberculosis infection alters the expression of host-cell genes, and these genes will provide a foundation for understanding the infection process of M. tuberculosis. The cDNA microarray is a powerful tool for studying pathogen-host cell interaction.

Cells, Cultured ; DNA, Complementary ; genetics ; Gene Expression ; Macrophages ; Oligonucleotide Array Sequence Analysis ; Tuberculosis ; genetics

OBJECTIVETo identify the egg antigens related to the formation of hepatic granulomas and fibrosis of Schistosomiasis japonica.

METHODSThe egg cDNA library of Schistosoma japonicum (S. japonicum) was constructed and screened by immunological methods with the pooled sera of advanced schistosomiasis patients. The inserted foreign DNA fragments of positive clones were sequenced. The sequence data were analyzed using Wdnasis 2.5 and compared with Genebank data using blast software.

RESULTSEighty-one clones containing recombinant DNA fragments were obtained from the egg cDNA library of S. japonicum by immunological screening. The DNA sequences of all clones belonged to the miracidial antigen family. The longest cDNA fragment was 1604 bp, which contained an open reading frame of 351 bp, which encoded a protein of 1 2913.35 daltons.

CONCLUSIONThe cDNA sequence of the miracidial antigen of S. japonicum (Chinese strain) was obtained for the first time.

Animals ; Antigens, Helminth ; genetics ; Base Sequence ; China ; DNA, Complementary ; analysis ; Ovum ; Schistosoma japonicum ; genetics ; immunology

AIMTo clone and analyse the coding cDNA sequence of alpha1, beta2 and gamma2 subunit of GABAA receptor in American king Pigeon.

METHODSWithdrew total RNA from the American king pigeon brain, reverse transcribing general primers to acquire a gene set cDNA. Designing specific primers of three subunit mRNA of the GABAA receptor, by RT-PCR respectively expanded the conservative gene of al subunit, beta2 subunit and gamma2 subunit of GABAA receptor, and carried on clone, plastid identification and the sequence measurese of three genes.

RESULTSThe experiment on sequence measures has succeeded that sequence analysis indicated that lengths of the conservative gene of alpha1 subunit, beta2 subunit and gamma2 subunit of GABAA receptor was respectively 899 bp, 597 bp and 563 bp, homology on reference sequence was respectively 94.99%, 94.64% and 96.28%.

CONCLUSIONHomology is high on the conservative gene of alpha1 subunit, beta2 subunit and gamma2 subunit of GABAA receptor of brain tissue of pigeon and chicken but there is a discriminating characteristic in different kinds of animals.

Animals ; Brain ; metabolism ; Cloning, Molecular ; Columbidae ; DNA, Complementary ; genetics ; RNA, Messenger ; genetics ; Receptors, GABA-A ; classification ; genetics ; Sequence Analysis, DNA

The development of inexpensive high throughput methods to identify individual DNA sequences is important to the future growth of medical genetics. This has become increasingly apparent as psychiatric geneticists focus more attention on the molecular basis of complex multifactorial diseases at which most of psychiatric disease is estimated. Furthermore, candidate gene approaches used in identifying disease associated genes necessitate screening large sequence blocks for changes tracking with the disease state. Even after such genes are isolated, large scale mutational analysis will often be needed for risk assessment studies to define the likely medical consequences of carrying a mutated gene. This review provide basic knowledge of up-to-date technology, cDNA microarray which enables above mentioned various research themes.
Base Sequence ; DNA, Complementary* ; Genetics, Medical ; Mass Screening ; Oligonucleotide Array Sequence Analysis* ; Risk Assessment

BACKGROUNDKeloid is an intricate lesion that is probably regulated by many genes. In this study, the authors used the technique of complementary DNA (cDNA) microarray to analyse abnormal gene expression in keloids and normal control skins.

METHODSThe polymerase chain reaction (PCR) products of 8400 genes were spotted in an array on chemical-material-coated-glass plates. The DNAs were fixed on the glass plates. The total RNAs were isolated from freshly excised human keloid and normal control skins, and the mRNAs were then purified. The mRNA from both keloid and normal control skins were reversely transcribed to cDNAs, with the incorporation of fluorescent dUTP, for preparing the hybridisation probes. The mixed probes were then hybridised to the cDNA microarray. After thorough washing, the cDNA microarray was scanned for differing fluorescent signals from two types of tissues. Gene expression of tissue growth factor-beta1 (TGF-beta1) and of c-myc was detected with both RT-PCR and Northern blot hybridisation to confirm the effectiveness of cDNA microarray.

RESULTSAmong the 8400 human genes, 402 were detected with different expression levels between keloid and normal control skins. Two hundred and fifty genes, including TGF-beta1 and c-myc, were up-regulated and 152 genes were down-regulated. Higher expressions of TGF-beta1 and c-myc in keloid were also revealed using RT-PCR and Northern blot methods.

CONCLUSIONcDNA microarray analysis provides a powerful tool for investigating differential gene expression in keloid and normal control skins. Keloid is a complicated lesion with many genes involved.

DNA, Complementary ; analysis ; Humans ; Keloid ; genetics ; Oligonucleotide Array Sequence Analysis ; methods ; Polymerase Chain Reaction ; RNA, Messenger ; analysis ; Skin

OBJECTIVETo construct a cDNA library from human liver tissue with chronic hepatitis B and check its quality for investigating the expression level of liver tissue infected by hepatitis B virus. This will then be used to find the relevant genes and interesting proteins associated with the development of hepatitis B.

METHODSThe total RNA from liver tissue with chronic hepatitis B was extracted and the mRNA was purified using TRIZOL method. Switching mechanism at 5' end of the RNA transcript (SMART) technique and CDS III/3' primer were used for first-strand cDNA synthesis. Long distance polymerase chain reaction (LD PCR) was then used to synthesize the double-strand cDNA that was then digested by Sfi I and fractionated by CHROMA SPIN-400 column. The longer than 0.4 kb cDNAs were collected and ligated to lambdaTriplEx2 vector. Then lambda phage packaging reaction and library amplification were performed. The qualities of both unamplified and amplified cDNA libraries were strictly checked by conventional titer determination. Fourteen plaques were randomly picked and tested using PCR with universal primers derived from the sequence flanking the vector.

RESULTSThe titers of unamplifed and amplified libraries were 1.94 x 10(6) pfu/ml and 1.49 x 10(9) pfu/ml respectively. The percentages of recombinants from both libraries were 98.15% in unamplified library and 98.76% in amplified library. The lengths of the inserts were 1.23 kb in average, 1-2 kb in 64.29%, and 0.5-1.0 kb in 35.71%.

CONCLUSIONA high quality cDNA library from human liver tissue with chronic hepatitis B was successfully constructed.

DNA, Complementary ; genetics ; Gene Library ; Hepatitis B, Chronic ; genetics ; Humans ; Liver ; metabolism ; pathology ; Polymerase Chain Reaction ; RNA ; analysis ; genetics

OBJECTIVETo study viruses infecting Pinellia ternata in China.

METHODSymptom observation, DAS-ELISA and RT-PCR detection were applied.

RESULT AND CONCLUSIONDuring a survey in early spring, SMV and CMV were both commonly distributed as main viruses infecting P. ternata collected from different areas in China. But DsMV was the virus which infected P. ternate in natural condition. The infection ratio of cultivated P. ternate by SMV and CMV were 71.4% and 14.3% respectively for 21 samples collected from Ningbo, Zhejiang province; 100% and 44.4% for 18 samples from Xiaoshan, Zhejiang province; 61.9% and 33.3% for 21 samples from Hebei province; 50.0% and 41.7% for 12 samples from Anhui province; 16.7% and 16.7% for 12 samples from Sichuan province; 31.3% and none for 16 samples from Beijing. And the infection ratio of 25 wild samples from different areas of China infected by SMV and CMV were both 20.0%.

China ; Cluster Analysis ; Cucumovirus ; genetics ; isolation & purification ; DNA, Complementary ; chemistry ; genetics ; Mosaic Viruses ; classification ; genetics ; isolation & purification ; Pinellia ; virology ; Plant Diseases ; virology ; Plants, Medicinal ; virology ; Sequence Analysis, DNA

BACKGROUND/AIMS: The fragile histidine triad (FHIT) gene located at chromosome 3p14.2, is a candidate tumor suppressor gene often involved in various tumors. Homozygous deletions, lack or reduced expression of FHIT protein, and alteration of its transcription were frequently observed in several types of primary human cancers and cell lines. In the present study, we examined the expression profiles of aberrant FHIT transcripts to explore the role of FHIT gene in gastric carcinogenesis. METHODS: In 6 gastric cancer cell lines, nested reverse transcription-polymerase chain reaction (RT-PCR) and cDNA sequence analyses were performed to detect and characterize the aberrant FHIT transcripts. RESULTS: In addition to the wild-type FHIT transcript, small-sized transcripts with various numbers and lengths were observed in all of the cell lines examined. cDNA sequence analysis confirmed that different types of truncated transcripts included exonic deletions, insertions of intron 5 sequences between exons, and combinations of both. Most of these transcripts lacked exon 5 in which translation initiation codon is located. Aberrant transcripts with partial exonic deletions due to activation of cryptic splice sites were also observed in 5 cell lines. Additionally, multi-step splice patterns indicative of additional downstream processing, were observed in several cancer lines. CONCLUSIONS: These results suggest that the aberrant FHIT transcripts in gastric cancer cell lines results from faulty splicing, including exon skipping, selection of cryptic splice site, and additional downstream splice processing.
*Acid Anhydride Hydrolases ; Cell Line, Tumor ; Codon, Initiator/genetics ; DNA, Complementary/genetics ; Genes, Tumor Suppressor ; Humans ; Neoplasm Proteins/*genetics ; *Sequence Analysis, DNA ; Stomach Neoplasms/*genetics ; *Transcription, Genetic

OBJECTIVETo investigate the splice variants of the calpain 3 gene existing in human skeletal muscle tissue and white blood cells, and to explore the feasibility of gene diagnosis using CAPN3 mRNA extracted from peripheral leukocytes.

METHODSTotal RNA was extracted from peripheral blood and skeletal muscle tissue in healthy individuals. CAPN3 cDNAs were determined by reverse transcriptase polymerase chain reaction and DNA sequencing. CAPN3 cDNAs from peripheral leukocytes were compared with sequences obtained from skeletal muscle tissue.

RESULTSRT-PCR and DNA sequencing showed that the CAPN3 cDNAs comprised 24 exons in human skeletal muscle tissue, while the number of exons was 23 in white blood cells. Exon 15 was spliced out in human white blood cells.

CONCLUSIONSplice variants exist in human skeletal muscle tissue and white blood cells. Gene diagnosis may omit the mutations of exon 15 using mRNA extracted from peripheral leukocytes. These findings suggest that mutation analysis of the CAPN3 cDNA should use skeletal muscle tissue as materials instead of peripheral blood.

Calpain ; genetics ; DNA Mutational Analysis ; DNA, Complementary ; genetics ; Exons ; genetics ; Humans ; Leukocytes ; metabolism ; Muscle Proteins ; genetics ; Muscle, Skeletal ; metabolism ; Reverse Transcriptase Polymerase Chain Reaction