• Title/Summary/Keyword: recombination

Search Result 1,238, Processing Time 0.032 seconds

Effects of Recombination on the Pathogenicity and Evolution of Pepper mottle virus

  • Jonson, Miranda Gilda;Seo, Jang-Kyun;Cho, Hong-Soo;Kim, Jeong-Soo;Kim, Kook-Hyung
    • The Plant Pathology Journal
    • /
    • v.25 no.4
    • /
    • pp.417-421
    • /
    • 2009
  • The analysis of the full length genome of Korean isolates of Pepper mottle virus (PepMoV) in previous study showed molecular variations and are found to be related to symptom variation and pathogenicity (Kim et al., 2009, Virus Res. 144:83-88). To fully understand the molecular variation of PepMoV in Korea, we further assessed the role of RNA recombination to biological variation and evolution of PepMoV. Full-length genome of a total of 17 Korean-PepMoV and 2 American (CA and FL) isolates were examined for possible detection of genetic recombination using different recombination detections programs and detected 5 and 8 tentative recombination events using RDP3 and Splits Tree4 programs, respectively. Interestingly, tentative recombinants detected such as isolates 57, 134 and 217 were previously identified as severe isolates and 205135 and 205136 as differentiating isolates (Kim et al., 2009, Virus Res. 144:83-88). In addition, recombination was frequently detected in the Vb isolate, the first PepMoV isolate reported in Korea, suggesting significant involvement in the evolution of PepMoV in Korea. These initial results of our recombination analyses among PepMoV isolates in Korea may serve as clues to further investigate the biological variations and evolution of PepMoV brought about by recombination.

Effect of Metal Mask Screen on Metal-induced Recombination Current and Solar Cell Characteristics (금속 마스크 스크린이 금속 재결합 전류와 태양전지 특성에 미치는 영향)

  • Lee, Uk Chul;Jeong, Myeong Sang;Lee, Joon Sung;Song, Hee-eun;Kang, Min Gu;Park, Sungeun;Chang, Hyo Sik;Lee, Sang Hee
    • Current Photovoltaic Research
    • /
    • v.9 no.1
    • /
    • pp.6-10
    • /
    • 2021
  • The mesh mask screen, which is generally used for screen printing metallization of silicon solar cell, requires high squeegee pressure and low printing speed. These requirements are acting as a limiting factor in production yield in photovoltaic industries. In order to improve the productivity, a metal mask, which has high durability and high printing speed, has been researched. In this paper, the characteristics of each solar cell, in which electrodes were formed by using a metal mask and a mesh mask, were analyzed through recombination current density. In particular, the metal-induced recombination current density (Jom) representing the recombination of the emitter-metal interface was calculated using the shading method, and the resulting efficiency and open-circuit voltage were analyzed through the diode equation. As a result of analyzing the proportion of the metal-induced recombination current density to the total emitter recombination current density, it was analyzed that the reduction of the metal-induced recombination current density through the metal mask is an important factor in reducing the total recombination current density of the solar cell.

PCR-mediated Recombination of the Amplification Products of the Hibiscus tiliaceus Cytosolic Glyceraldehyde-3-phosphate Dehydrogenase Gene

  • Wu, Linghui;Tang, Tian;Zhou, Renchao;Shi, Suhua
    • BMB Reports
    • /
    • v.40 no.2
    • /
    • pp.172-179
    • /
    • 2007
  • PCR-mediated recombination describes the process of in vitro chimera formation from related template sequences present in a single PCR amplification. The high levels of genetic redundancy in eukaryotic genomes should make recombination artifacts occur readily. However, few evolutionary biologists adequately consider this phenomenon when studying gene lineages. The cytosolic glyceraldehyde-3-phosphate dehydrogenase gene (GapC), which encodes a NADP-dependent nonphosphorylating glyceraldehyde-3-phosphate dehydrogenase in the cytosol, is a classical lowcopy nuclear gene marker and is commonly used in molecular evolutionary studies. Here, we report on the occurrence of PCR-mediated recombination in the GapC gene family of Hibiscus tiliaceus. The study suggests that recombinant areas appear to be correlated with DNA template secondary structures. Our observations highlight that recombination artifacts should be considered when studying specific and allelic phylogenies. The authors suggest that nested PCR be used to suppress PCRmediated recombination.

Ku complex suppresses recombination in the absence of MRX activity during budding yeast meiosis

  • Yun, Hyeseon;Kim, Keunpil
    • BMB Reports
    • /
    • v.52 no.10
    • /
    • pp.607-612
    • /
    • 2019
  • During meiosis, programmed double-strand breaks (DSBs) are repaired via recombination pathways that are required for faithful chromosomal segregation and genetic diversity. In meiotic progression, the non-homologous end joining (NHEJ) pathway is suppressed and instead meiotic recombination initiated by nucleolytic resection of DSB ends is the major pathway employed. This requires diverse recombinase proteins and regulatory factors involved in the formation of crossovers (COs) and non-crossovers (NCOs). In mitosis, spontaneous DSBs occurring at the G1 phase are predominantly repaired via NHEJ, mediating the joining of DNA ends. The Ku complex binds to these DSB ends, inhibiting additional DSB resection and mediating end joining with Dnl4, Lif1, and Nej1, which join the Ku complex and DSB ends. Here, we report the role of the Ku complex in DSB repair using a physical analysis of recombination in Saccharomyces cerevisiae during meiosis. We found that the Ku complex is not essential for meiotic progression, DSB formation, joint molecule formation, or CO/NCO formation during normal meiosis. Surprisingly, in the absence of the Ku complex and functional Mre11-Rad50-Xrs2 (MRX) complex, a large portion of meiotic DSBs was repaired via the recombination pathway to form COs and NCOs. Our data suggested that Ku complex prevents meiotic recombination in the elimination of MRX activity.

Analysis of Lambda Site-specific Recombination Inermediates Generated by Synthetic Substrates (합성 기질에 의해 형성된 Lambda Site-specific Recombination 중간 대사물의 분석)

  • 이나영;유승구
    • Microbiology and Biotechnology Letters
    • /
    • v.23 no.3
    • /
    • pp.282-287
    • /
    • 1995
  • Integrase (Int) carries out the cutting and resealing of attachment (att) site DNA via a covalent Int-DNA intermediate. A family of synthetic substrate DNAs was designed to accumulate Int-DNA intermediate. Int-DNA intermediates accumulated by half substrate was analyzed by SDS- KCI precipitation and restriction digestion. The results showed that Int-half DNA intermediate was circular and contained covalently bound Int molecule. Int-DNA intermediates were also trapped with three other kinds of synthetic substrates.

  • PDF

Development of a novel genetic assay for telomere recombination in Saccharomyces cerevisiae (효모에서 텔로미어 재조합을 관찰하기 위한 새로운 유전학적 연구방법의 개발)

  • Kim, Min-Kyu;Bae, Sung-Ho
    • Korean Journal of Microbiology
    • /
    • v.52 no.1
    • /
    • pp.116-119
    • /
    • 2016
  • Stable maintenance of telomere is required for cell proliferation and survival. Although telomerase is the primary means for telomere maintenance, recombination is another important pathway to maintain telomeres. In this study, we developed a genetic assay for telomere recombination using the internal $TG_{1-3}$ repeats present in subtelomeric regions of yeast. The recombination frequencies were dependent on the presence of the internal $TG_{1-3}$ repeats. PCR amplification of the regions near URA3 and CAN1 markers using genomic DNA isolated from $FOA^rCan^r$ colonies indicated that each isolate had lost the chromosome end including the markers. In addition, the recombination frequencies increased with longer internal $TG_{1-3}$ repeats. Our results suggest that the $FOA^rCan^r$ colony formation is the consequence of recombination between the internal and terminal $TG_{1-3}$ repeats.

Preincubation without attB DNA inhibits In Vitro Integrative Recombination of P 1 Mutant attP DNA of Bacteriophage Lambda

  • Yoo, Seung-Ku
    • Journal of Microbiology and Biotechnology
    • /
    • v.5 no.3
    • /
    • pp.132-137
    • /
    • 1995
  • The lambda integrase (lnt) is believed to bind to several arm and core sites of attP DNA in order to facilitate intasome formation. We have done systematic mutagenic analysis on all 5 arm sites and found that P1 is absolutely required for integration while P2 is not. We also found that all 3 P' arm sites(P'1, P'2, and P'3) are required for efficient integrative recombination. P'1, which is an important binding site for excision, also seems to be crucial for integration when preincubation of attP DNA with Int and IHF is performed before recombination. Preincubation assay revealed that preincubation with Int and IHF improved the efficiency of recombination of wild type attP DNA and demolished recombinations of P'1 mutant attP DNAs.

  • PDF

Electrochemical spike oscillation st the Ni electrode interface (Ni 전극 계면에서 전기화학적 spike 발진)

  • 천장호;손광철;라극환
    • Journal of the Korean Institute of Telematics and Electronics A
    • /
    • v.33A no.12
    • /
    • pp.83-89
    • /
    • 1996
  • The electrochemical spike oscillations at the nickel (Ni) electrode/(0.05M KHC$_{8}$H$_{4}$O$_{4}$) buffer solution (pH 9) interface have been studied using voltammetric and chronoamperometric methods. The nature of the periodic cathodic current spikes is the activation controlled currents due to the hydrogen evolution reaction and depends onthe fractioanl surface coverage of the adsorbed hydrogen intermediate or the cathodic potential. There is two kinds of the waveforms corresponding to two kinds of the cathodic current spike oscillations. The widths, periods, and amplitudes of the cathodic current spikes are 4 ms or 5ms, 151 ms or 302 ms, and < 30 mA or < 275 mA, respectively. The fast discharge and recombination reaction steps are 1.5 times and twice and faster than the slow discharge and recombination reaction steps. The fast and slow discharge and recombination reaction steps are 1.5 times and twice faster than the slow discharge and recombination reaction steps. The fast and slow discharge and recombination reactions corresponding to the fast and slow adsorption sites at the Ni cathode.

  • PDF

New Tunneling Model Including both the Thermal and the Tunneling Transition through Trap (트랩을 통한 열적 천이와 터널링 천이를 동시에 고려할 수 있는 새로운 터널링 모델에 관한 연구)

  • 박장우;곽계달
    • Journal of the Korean Institute of Telematics and Electronics A
    • /
    • v.29A no.8
    • /
    • pp.71-77
    • /
    • 1992
  • According to increasing the doping concentration in p-n junction, a tunneling current through trap as well as SRH(Shockley-Read-Hall) generation-recombination current in depletion region occurs. It is the tunneling current that is a dominant current at the forward bias. In this paper, the new tunneling-recombination equation is derived. The thermal generation-recombination current and tunneling current though trap can be easily calculated at the same time because this equation has the same form as the SRH generation-recombination equation. For the validity of this equation, 2 kind of samples are simulated. The one is $n^{+}$-p junction device fabricated with MCT(Mercury Cadmium Telluride, mole fraction=0.29), the other Si n$^{+}-p^{+}$ junction. From the results for MCT $n^{+}$-p junction device and comparing the simulated and expermental I-V characteristics for Si n$^{+}-p^{+}$ junction, it is shown that this equation is a good description for tunneling through trap and thermal generation-recombination current calculation.

  • PDF

Noise Robust Speaker Identification using Reliable Sub-Band Selection in Multi-Band Approach (신뢰성 높은 서브밴드 선택을 이용한 잡음에 강인한 화자식별)

  • Kim, Sung-Tak;Ji, Mi-Gyeong;Kim, Hoi-Rin
    • Proceedings of the KSPS conference
    • /
    • 2007.05a
    • /
    • pp.127-130
    • /
    • 2007
  • The conventional feature recombination technique is very effective in the band-limited noise condition, but in broad-band noise condition, the conventional feature recombination technique does not produce notable performance improvement compared with the full-band system. To cope with this drawback, we introduce a new technique of sub-band likelihood computation in the feature recombination, and propose a new feature recombination method by using this sub-band likelihood computation. Furthermore, the reliable sub-band selection based on the signal-to-noise ratio is used to improve the performance of this proposed feature recombination. Experimental results shows that the average error reduction rate in various noise condition is more than 27% compared with the conventional full-band speaker identification system.

  • PDF