• Title/Summary/Keyword: reverse genetics

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Repression of HspA2 mRNA Expression in Human Testes with Abnormal Spermatogenesis (비정상적 정자형성 환자의 정소에서 Heat Shock Protein A2 (hspA2) mRNA 발현의 감소)

  • Son, W.Y.;Hwang, S.H.;Han, C.T.;Lee, J.H.;Kim, S.J.;Kim, Y.C.
    • Clinical and Experimental Reproductive Medicine
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    • v.26 no.1
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    • pp.103-109
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    • 1999
  • Objective: Heat shock protein 70-2 (Hsp70-2) gene knockout mice are found to have premeiotic arrest at the primary spermatocyte stage with a complete absence of spermatids and spermatozoa. This observation led to the hypothesis that hspA2 may be disrupted in human testes with abnormal spermatogenesis. To test this hypothesis, we studied the mRNA expression of hspA2 in infertile men with azoospermia. Design: The mRNA expression were analyzed by competitive RT-PCR among testes with normal spermatogenesis, pachytene spermatocyte arrest, and sertoli-cell only syndrome. Materials and methods: Testicular biopsy was performed in men with azoospermia (n=15). Specimens were subdivided into three groups: (group 1) normal spermatogenesis (n=5), (group 2) spermatocyte arrest (n=5), (group 3) Sertoli-cell only syndrome (n=5). Total RNA was extracted by Trizol reagent. Total extracted RNA was reverse transcribed into cDNA and amplified by PCR using specific primers for hspA2 target cDNAs. A competitive cDNA fragment was constructed by deleting a defined fragment from the target cDNA sequence, and then coamplified with the target cDNA for competitive PCR. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene was used as an internal control. Results: On Competitive RT-PCR analyses for hspA2 mRNA, significant amount of hspA2 expression was observed in group 1, whereas a constitutively low level of hspA2 was expressed in groups 2 and 3. Conclusion(s): The study demonstrates that the hspA2 gene expression is down-regulated in human testes with abnormal spermatogenesis, which in turn suggests that hspA2 gene may play a specific role during meiosis in human testes.

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A study on the patterns of expression of the DAZ and HSP genes in the testicular tissue of men with azoospermia

  • Lee, Ho-Joon;Lee, Hyoung-Song;Song, Gyun-Jee;Byun, Hye-Kyung;Cho, Youl-Hee;Kim, Jong-Hyun;Seo, Ju-Tae;Lee, Yoo-Sik
    • Journal of Genetic Medicine
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    • v.1 no.1
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    • pp.51-56
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    • 1997
  • Spermatogenesis is known to be regulated by a number of genes and several factors such as hormones, growth factors, cytokines and others. This study was done to evaluate the relationship between HSPs and DAZ genes in human spermatogenesis; we observed the expression pattern of HSP gene in azoospermia men with DAZ gene that regulated the gene expression related with human spermatogenesis. RT-PCR method was used to detect DAZ, HSP70A, and HSP70B transcripts in all RNA samples. Total RNA was extracted from 21 testis tissues using TRIZOL reagent. cDNAs were synthesized with reverse transcriptase, AMV. All PCR reaction were performed on a PCR themocycler with DAZ, HSP70A, and HSP70B-specific primers. Semen analysis, karyotyping and testis histology were performed. DAZ gene, known as a candidate gene of azoospermia factor(AZF), was deleted in 2 of 21 patients. To evaluate the only effects of HSPs in this patients, 2 DAZ deleted cases were removed. We observed the mRNA of HSP70B in 5 whereas none could be seen with regard to HSP70A. Furthermore, the sperm of these 5 men were discovered to be immature. In conclusion, HSP70B as well ad DAZ gene seem to be involved causing spermatogenic failure. We suggest that HSP70B plays an important role in spermatogenesis and it is one of factors induced sperm maturation in human.

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Antibacterial Mode of Action of Cinnamomum verum Bark Essential Oil, Alone and in Combination with Piperacillin, Against a Multi-Drug-Resistant Escherichia coli Strain

  • Yap, Polly Soo Xi;Krishnan, Thiba;Chan, Kok-Gan;Lim, Swee Hua Erin
    • Journal of Microbiology and Biotechnology
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    • v.25 no.8
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    • pp.1299-1306
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    • 2015
  • This study aims to investigate the mechanism of action of the cinnamon bark essential oil (CB), when used singly and also in combination with piperacillin, for its antimicrobial and synergistic activity against beta-lactamase TEM-1 plasmid-conferred Escherichia coli J53 R1. Viable count of bacteria for this combination of essential oil and antibiotic showed a complete killing profile at 20 h and further confirmed its synergistic effect by reducing the bacteria cell numbers. Analysis on the stability of treated cultures for cell membrane permeability by CB when tested against sodium dodecyl sulfate revealed that the bacterial cell membrane was disrupted by the essential oil. Scanning electron microscopy observation and bacterial surface charge measurement also revealed that CB causes irreversible membrane damage and reduces the bacterial surface charge. In addition, bioluminescence expression of Escherichia coli [pSB1075] and E. coli [pSB401] by CB showed reduction, indicating the possibility of the presence of quorum sensing (QS) inhibitors. Gas-chromatography and mass spectrometry of the essential oil of Cinnamomum verum showed that trans-cinnamaldehyde (72.81%), benzyl alcohol (12.5%), and eugenol (6.57%) were the major components in the essential oil. From this study, CB has the potential to reverse E. coli J53 R1 resistance to piperacillin through two pathways; modification in the permeability of the outer membrane or bacterial QS inhibition.

Role of MAPK Signaling Pathways in Regulating the Hydrophobin Cryparin in the Chestnut Blight Fungus Cryphonectria parasitica

  • So, Kum-Kang;Kim, Dae-Hyuk
    • Mycobiology
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    • v.45 no.4
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    • pp.362-369
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    • 2017
  • We assessed the regulation of cryparin, a class II hydrophobin, using three representative mitogen-activated protein kinase (MAPK) pathways in Cryphonectria parasitica. Mutation of the CpSlt2 gene, an ortholog of yeast SLT2 in the cell wall integrity (CWI) pathway, resulted in a dramatic decrease in cryparin production. Similarly, a mutant of the CpBck1 gene, a MAP kinase kinase kinase gene in the CWI pathway, showed decreased cryparin production. Additionally, mutation of the cpmk1 gene, an ortholog of yeast HOG1, showed decreased cryparin production. However, mutation of the cpmk2 gene, an ortholog of yeast Kss1/Fus3, showed increased cryparin production. The easy-wet phenotype and accumulation of the cryparin transcript in corresponding mutants were consistent with the cryparin production results. In silico analysis of the promoter region of the cryparin gene revealed the presence of binding motifs related to downstream transcription factors of CWI, HOG1, and pheromone responsive pathways including MADS-box- and Ste12-binding domains. Real-time reverse transcriptase PCR analyses indicated that both CpRlm1, an ortholog of yeast RLM1 in the CWI pathway, and cpst12, an ortholog of yeast STE12 in the mating pathway, showed significantly reduced transcription levels in the mutant strains showing lower cryparin production in C. prasitica. However, the transcription of CpMcm1, an ortholog of yeast MCM1, did not correlate with that of the mutant strains showing downregulation of cryparin. These results indicate that three representative MAPK pathways played a role in regulating cryparin production. However, regulation varied depending on the MAPK pathways: the CWI and HOG1 pathways were stimulatory, whereas the pheromone-responsive MAPK was repressive.

Nail DNA and Possible Biomarkers: A Pilot Study

  • Park, Joshua;Liang, Debbie;Kim, Jung-Woo;Luo, Yongjun;Huang, Taesheng;Kim, Soo-Young;Chang, Seong-Sil
    • Journal of Preventive Medicine and Public Health
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    • v.45 no.4
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    • pp.235-243
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    • 2012
  • Objectives: Nail has been a substitute DNA source for genotyping. To investigate the integrity and consistency of nail DNA amplification for biomarker study, nail clippings from 12 subjects were collected at monthly intervals. The possibility of longer amplification and existence of GAPDH RNA/protein, were also investigated with three nail samples. Methods: Three primer sets were designed for quantitative amplification of nuclear and mitochondrial genes and analysis of their consistency. The mean threshold cycles in amplification of the target genes were compared to test the consistency of polymerase chain reaction (PCR) performance among individual factors including age groups, sex, family, the nail source, and by the size of the amplification segments. Results: The amplification of the target genes from nail DNA showed similar integrity and consistency between the nail sources, and among the serial collections. However, nail DNA from those in their forties showed earlier threshold cycles in amplification than those in their teens or seventies. Mitochondrial DNA (mtDNA) showed better DNA integrity and consistency in amplification of all three targets than did nuclear DNA (nucDNA). Over 9 kb of mtDNA was successfully amplified, and nested quantitative PCR showed reliable copy numbers (%) between the two loci. Reverse transcription PCR for mRNA and immunoblotting for GAPDH protein successfully reflected their corresponding amounts. Regarding the existence of RNA and protein in nails, more effective extraction and detection methods need to be set up to validate the feasibility in biomarker study. Conclusions: Nail DNA might be a feasible intra-individual monitoring biomarker. Considering integrity and consistency in target amplification, mtDNA would be a better target for biomarker research than nucDNA.

Development of New Molecular Markers for the Identification of Male Sterile Cytoplasm in Peppers (Capsicum annuum L.)

  • Min, Woong-Ki;Kim, Byung-Dong;Kim, Sung-Gil;Lee, Sang-Hyeob
    • Horticultural Science & Technology
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    • v.29 no.1
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    • pp.53-60
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    • 2011
  • Cytoplasmic male sterility (CMS) induced by mutant mitochondria genome, has been used for commercial seed production of $F_1$ hybrid cultivars in diverse crops. In pepper (Capsicum annuum L.), two sterile cytoplasm specific gene organization, atp6-2 and coxII were identified. An open reading frame, orf456 nearby coxII gene has been speculated to induce male sterility (MS) by mutagenic analysis. Moreover, molecular markers for atp6-2 and coxII of mitochondrial genotype (mitotype) were developed. However, the Cytoplasmic MS specific markers, atp6SCAR and coxIISCAR markers appeared in both N and S cytoplasms when polymerase chain reaction (PCR) cycles prolonged more than 40 cycles. Since the reported molecular markers were dominant markers, the presence of the faint sterile-specific band in normal cytoplasm may lead to the mis-classification of pepper breeding lines. To solve this problem, one common forward primer and two different reverse primers specific to normal coxII and sterile orf456 genes were designed after analyzing their gene organizations. By using these three primers, N and S coxII specific bands were co-amplified in male-sterile lines, but only normal coxII specific band was amplified in maintainer lines. Since the reverse primer for sterile coxII was specifically designed 275 bp downstream of orf456, relatively stable PCR amplification patterns were observed regardless of the number of PCR cycles. These primer sets easily identified different mitotypes among the divergent breeding lines, commercial cultivars and diverse germplasms.

Overexpression of Ubiquitin and Amino Acid Permease Genes in Association with Antimony Resistance in Leishmania tropica Field Isolates

  • Kazemi-Rad, Elham;Mohebali, Mehdi;Erfan, Mohammad Bagher Khadem;Hajjaran, Homa;Hadighi, Ramtin;Khamesipour, Ali;Rezaie, Sassan;Saffari, Mojtaba;Raoofian, Reza;Heidari, Mansour
    • Parasites, Hosts and Diseases
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    • v.51 no.4
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    • pp.413-419
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    • 2013
  • The mainstay therapy against leishmaniasis is still pentavalent antimonial drugs; however, the rate of antimony resistance is increasing in endemic regions such as Iran. Understanding the molecular basis of resistance to antimonials could be helpful to improve treatment strategies. This study aimed to recognize genes involved in antimony resistance of Leishmania tropica field isolates. Sensitive and resistant L. tropica parasites were isolated from anthroponotic cutaneous leishmaniasis patients and drug susceptibility of parasites to meglumine antimoniate (Glucantime$^{(R)}$) was confirmed using in vitro assay. Then, complementary DNA-amplified fragment length polymorphism (cDNA-AFLP) and real-time reverse transcriptase-PCR (RT-PCR) approaches were utilized on mRNAs from resistant and sensitive L. tropica isolates. We identified 2 known genes, ubiquitin implicated in protein degradation and amino acid permease (AAP3) involved in arginine uptake. Also, we identified 1 gene encoding hypothetical protein. Real-time RT-PCR revealed a significant upregulation of ubiquitin (2.54-fold), and AAP3 (2.86-fold) (P<0.05) in resistant isolates compared to sensitive ones. Our results suggest that overexpression of ubiquitin and AAP3 could potentially implicated in natural antimony resistance.

Identification of differentially expressed genes in the developmental stages from olive flounder Paralichthys olivaceus using an annealing control primer system

  • Kim, Young-Ok;Park, Eun-Mi;Nam, Bo-Hye;Kong, Hee-Jeong;Kim, Woo-Jin;Noh, Jae-Koo;Lee, Sang-Jun;Kim, Kyung-Kil
    • Animal cells and systems
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    • v.14 no.1
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    • pp.25-30
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    • 2010
  • We employed a new and improved differential display reverse transcription-polymerase chain reaction (DDRT-PCR) method, which involves annealing control primers (ACPs), to identify the genes that are specifically or prominently expressed in olive flounder (Paralichthys olivaceus) juveniles (35 days post-hatch; dph) compared to larval-stage (dph 21) flounder. Using 60 ACPs, we identified eight differentially expressed genes (DEGs) and basic local alignment search tool (BLAST) searches revealed eight known genes. Gene expression levels were confirmed by RT-PCR. Phosphoglucose isomerase (PGI) was highly expressed at 21 dph, while nephrosin, myosin light chain (MLC), myosin heavy chain (MHC), carboxypeptidase A, chymotrypsin B, fish-egg protein, and matrix protein were expressed at 35 dph. PGI, MLC, and MHC expression was further analyzed by RT-PCR. The differentially expressed genes identified in this study may provide insights into the molecular basis of development in olive flounder.

Overview of Arabidopsis Resource Project in Japan

  • Kobayashi, Masatomo
    • Interdisciplinary Bio Central
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    • v.3 no.1
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    • pp.2.1-2.4
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    • 2011
  • Arabidopsis is well-known to the world's plant research community as a model plant. Many significant resources and innovative research tools, as well as large bodies of genomic information, have been created and shared by the research community, partly explaining why so many researchers use this small plant for their research. The genome sequence of Arabidopsis was fully characterized by the end of the $20^{th}$ century. Soon afterwards, the Arabidopsis research community began a 10-year international project on the functional genomics of the species. In 2001, at the beginning of the project, the RIKEN BioResource Center (BRC) started its Arabidopsis resource project. The following year, the National BioResource Project was launched, funded by the Japanese government, and the RIKEN BRC was chosen as a core facility for Arabidopsis resource. Seeds of RIKEN Arabidopsis transposon-tagged mutant lines, activation-tagged lines, full-length cDNA over-expresser lines, and natural accessions, as well as RIKEN Arabidopsis full-length cDNA clones and T87 cells, are preserved at RIKEN BRC and distributed around the world. The major resources provided to the research community have been full-length cDNA clones and insertion mutants that are suitable for use in reverse-genetics studies. This paper provides an overview of the Arabidopsis resources made available by RIKEN BRC and examples of research that has been done by users and developers of these resources.

Production of Biosurfactant Lipopeptides Iturin A, Fengycin, and Surfactin A from Bacillus subtilis CMB32 for Control of Colletotrichum gloeosporioides

  • Kim, Pyoung-Il;Ryu, Jae-Won;Kim, Young-Hwan;Chi, Youn-Tae
    • Journal of Microbiology and Biotechnology
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    • v.20 no.1
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    • pp.138-145
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    • 2010
  • A bacterial strain isolated from soil for its potential to control the anthracnose disease caused by Colletotrichum gloeosporioides was identified as a Bacillus subtilis. Bacillus subtilis CMB32 produced antifungal agents on M9 broth at $30^{\circ}C$. Biosurfactant lipopeptides produced by Bacillus subtilis CMB32 were precipitated by adjusting to pH 2 and extracting using chloroform/methanol, and then were purified using column chromatography and reverse-phase HPLC. The molecular masses of the lipopeptides were estimated by MALDI-TOF mass spectrometry as (a) 1,080, (b) 1,486, and (c) 1,044 Da, respectively. They had cyclic structures and amino acid compositions of (a) Pro, Asx, Ser, Tyr, Glx, (b) Glx, Tyr, Thr, Ala, Pro, lie, and (c) Glx, Leu, Val, Asx, respectively. Further analysis revealed that Bacillus subtilis CMB32 produced three antifungal lipopeptides: (a) iturin A, (b) fengycin, and (c) surfactin A.