• IMMUNE NETWORK
• /
• 제2권2호
• /
• pp.79-85
• /
• 2002

Background: In contrast to evidences of Ig H chain receptor editing in transformed cell lines and transgenic mouse models, there has been no direct evidence that this phenomenon occurs in human developing B cells. Methods: $V_HDJ_H$ rearrangements were obtained from genomic DNA of individual $IgM^-$ B cells from liver and $IgM^+B$ cells from bone marrow of 18 wk of gestation human fetus by PCR amplification and direct sequencing. Results: We found three examples of H chain receptor editing from $IgM^+$ and $IgM^-human$ fetal B cells. Two types of $V_H$ replacements were identified. The first involved $V_H$ hybrid formation, in which part of a $V_H$ gene from the initial VDJ rearrangement is replaced by part of an upstream $V_H$ gene at the site of cryptic RSS. The second involved a gene conversion like replacement of CDR2, in which another $V_H$ gene donated a portion of its CDR2 sequence to the initial VDJ rearrangement. Conclusion: These data provide evidence of receptor editing at the H chain loci in developing human B cells, and also the first evidence of a gene conversion event in human Ig genes.

• 대한수의학회지
• /
• 제60권3호
• /
• pp.109-116
• /
• 2020

This study aimed to develop a semi-nested polymerase chain reaction assay for the direct detection of Mycoplasma synoviae (M. synoviae) from clinical samples using three newly designed oligonucleotide primers specific to the variable lipoprotein haemagglutinin (vlhA) gene and differentiate M. synoviae field strains based on a nucleotide deletion or the insertion of the proline-rich repeat (PRR) region of the vlhA gene. The developed semi-nested polymerase chain reaction (PCR) assay revealed positive results in 12 out of 100 clinical samples collected from chickens showing lameness and joint swelling. Six positive samples were selected randomly for sequencing, and sequence analysis revealed 96.3-100% nucleotide identities compared to the reference sequences. Phylogenetic analysis showed that sequences of the strains in this study were closely related to WVU1853 (Spain), CK.MS.UDL.PK.2014.2 (Pakistan), and F10-2AS (USA) strains, but they were distinct from the M. synoviae-H vaccine strain sequence. M. synoviae obtained from these samples were identified as types A and C with a length of 38 and 32 amino acids, respectively. These results indicated that the specific and sensitive semi-nested PCR could be a useful diagnostic tool for the direct identification of clinical samples, and the sequence analysis of the partial vlhA gene can be useful for typing M. Synoviae.

• Asian Pacific Journal of Cancer Prevention
• /
• 제13권4호
• /
• pp.1151-1158
• /
• 2012

High-risk human papillomavirus (HPV) genotypes are the major cause of cervical cancer. Hence, HPV genotype detection is a helpful preventive measure to combat cervical cancer. Recently, several HPV detection methods have been developed, each with different sensitivities and specificities. The objective of this study was to compare HPV high risk genotype detection by an electrochemical DNA chip system, a line probe assay (INNO-LiPA) and sequencing of the L1, E1 regions. A total of 361 cervical smears with different cytological findings were subjected to polymerase chain reaction-sequencing and electrochemical DNA chip assessment. Multiple infections were found in 21.9% (79/361) of the specimens, most prevalently in 20-29-year olds while the highest prevalence of HPV infection was found in the 30-39-year age group. The most prevalent genotype was HPV 16 at 28.2% (138/489) followed by HPV 52 at 9.6% (47/489), with the other types occurring at less than 9.0%. The electrochemical DNA chip results were compared with INNO-LiPA and sequencing (E1 and L1 regions) based on random selection of 273 specimens. The results obtained by the three methods were in agreement except for three cases. Direct sequencing detected only one predominant genotype including low risk HPV genotypes. INNO-LiPA identified multiple infections with various specific genotypes including some unclassified-risk genotypes. The electrochemical DNA chip was highly accurate, suitable for detection of single and multiple infections, allowed rapid detection, was less time-consuming and was easier to perform when compared with the other methods. It is concluded that for clinical and epidemiological studies, all genotyping methods are perfectly suitable and provide comparable results.

• 대한임상검사과학회지
• /
• 제52권3호
• /
• pp.229-236
• /
• 2020

임상 검체에서 분리된 65개의 사상형 진균을 대상으로 연구하였다. 이 균주들은 형태학적으로 동정이 불가능한 진균, 형태학적으로 유사하여 동정이 까다로운 균주, 종(species) 수준의 동정이 요구되는 균종들이다. PCR과 염기서열분석은 ITS. DiD2, 그리고 β-tubulin 유전자를 표적 부위로 하였고, 증폭된 염기서열은 상동성 분석을 위하여 GenBank 데이터베이스의 알고리즘을 이용하여 분석하였다. 형태학적으로 속 수준의 동정이 가능한 진균은 61.5%이었고, 65주의 염기서열분석으로 62 균주는 속과 종의 동정이 가능하였다. 형태학적 검사와 염기서열분석의 결과, 속과 종이 불일치한 경우 14주(21.5%)이었고, 형태학적으로 동정이 불가능하였던 사례는 11 균주이었다. B. dermatitidis, T. marneffei, 그리고 G. argillacea 등은 염기서열분석으로 국내에서 처음으로 확인하였다. Aspergillus와 같이 흔히 분리되고 성장이 빠른 진균들의 경우에는 형태학적인 검사가 보고시간과 비용 면에서는 매우 유용한 방법이다. 분자유전학적인 검사 방법은 비용과 임상적 중요성 등을 고려하여야 하지만 분자유전학적 검사를 병행하여 신속하고 정확한 결과를 제공할 수 있다.

• Journal of Microbiology
• /
• 제45권2호
• /
• pp.168-170
• /
• 2007

In this research 26 Shigella isolates were examined by PCR and direct nucleotide sequencing for genetic alterations in the quinolone-resistance determining regions (QRDRs). We tested for the presence of qnr genes by PCR in 91 strains, but no qnr genes were found. The results did show, however, some novel mutations at codon 83 of gyrA ($Ser{\rightarrow}Ile$) and codon 64 of parC ($Ala64{\rightarrow}Cys,\;Ala64{\rightarrow}Asp$), which were related to fluroquinolone resistance.

• BMB Reports
• /
• 제40권5호
• /
• pp.801-804
• /
• 2007

The products of reactions catalyzed by Methanococcus. jannaschii (Mj) aldolase using various substrates were identified by gas chromatography (GC). Although Mj aldolase is considered a fuculose-1-phosphate aldolase based on homology searching after gene sequencing, it has not been proven to be a fuculose-1-phosphate aldolase based on its reaction products. Mj aldolase was found to catalyze reactions between glycoaldehyde or D, L-glyceraldehyde and DHAP (dihydroxyacetone phosphate). Before performing GC the ketoses produced were converted into peracetylated alditol derivatives by sequential reactions, i.e., dephosphorylation, $NaBH_4$ reduction, and acetylation. By comparing the GC data of final products with those of standard alditol samples, it was found that the enzymatic reactions with glycoaldehyde, D-glyceraldehyde, and D, L-glyceraldehyde produced D-ribulose-1-phosphate, D-psicose-1-phosphate, and a mixture of D-psicose and L-tagatose-1-phosphate, respectively. These results provide direct evidence that Mj aldolase is a fuculose-1-phosphate aldolase.

• Journal of the korean society of oceanography
• /
• 제35권3호
• /
• pp.158-160
• /
• 2000

The relativity of four isolates of C. polykrikoides was determined by comparative sequence analysis based on direct sequencing of PCR amplified ribosomal DNA (the internal transcribed spacer region and the 5.8S rDNA). Sequence comparisons indicated that four isolates had the same nucleotide sites in the ITS regions, as well as a total of 585 nucleotide length and 100% homology. The molecular data revealed that C. polykrikoides in Korean coastal waters show no genetical difference.

• Annals of Clinical Neurophysiology
• /
• 제11권2호
• /
• pp.59-63
• /
• 2009

Miyoshi myopathy (MM) is caused by the mutations of dysferlin gene (DYSF), which impairs the function of dysferlin protein causing muscle membrane dysfunction. We report a patient showing the MM phenotype who has a sister with LGMD 2B phenotype, along with the results of the immunohistochemical and molecular analyses of the DYSF gene. Immunohistochemical analysis noted negative immunoreactivity against dysferlin. Direct DNA sequencing of whole exons of DYSF gene revealed heterozygous nonsense mutations (c.610C>T + c.2494C>T). To our knowledge, this is the first reported MM case with this very combination of heterozygous mutations.

• 한국멀티미디어학회논문지
• /
• 제9권12호
• /
• pp.1628-1635
• /
• 2006

A new frequency-modulated m-sequence correlation technique was described. It has. been seen that the frequency modulation scheme leads to higher signal-to-noise ratio than direct sequencing and less hardware effort than PSK modulation scheme. The operating frequency of the correlation system was deduced. The optimal frequency for the frequency-modulated m-sequence correlation system should be 1.35 times of the center frequency of the transducer. The application of this correlation technique to electromagnetic ultrasonic system was computer-simulated.

• 미생물학회지
• /
• 제30권6호
• /
• pp.479-482
• /
• 1992

The sequence of the cytoplasmic 5S-rRNA from Trimorphomyces papilionaceus, a basidiomycetous yeast, was determined by the direct chemical method for sequencing RNA and compared to known 5S rRNA sequences of 19 basidiomycetous fuungi. There were 26 nucleotide differences between T. papilionaceus and Tremella mesenterica both of which belong to the Tremellaceae of the Tremellales. Based on Knuc values, the closest fungus was Tilletiaria anomala, another basidiomycetous yeast which belong to the Sporbolomycetaceae of the Sporobolomycetales. T. papilionaceus did not show any significant phylogenetic relationship with other fungi.