• Title/Summary/Keyword: hybridization%28FISH%29

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Centromere Repeat DNA Originated from Brassica rapa is Detected in the Centromere Region of Raphanus sativus Chromosomes

  • Hwang, Yoon-Jung;Yu, Hee-Ju;Mun, Jeong-Hwan;Bok, Kwang;Park, Beom-Seok;Lim, Ki-Byung
    • Horticultural Science & Technology
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    • v.30 no.6
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    • pp.751-756
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    • 2012
  • Fluorescence in situ hybridization (FISH) is a powerful tool for the detection of DNA sequences in the specific region of the chromosomes. As well as for the integrated physical mapping, FISH karyotype analysis has to be preceded. Karyotype of Raphanus sativus 'Wonkyo 10039' was analyzed by a dual-color FISH technique; using various repetitive DNA probes, including 5S rDNA, 45S rDNA, and centromere retrotransposon. The length of the somatic metaphase chromosome ranged from 1.35 to $2.06{\mu}m$ with a total length of $15.29{\mu}m$. The chromosome complements comprised of eight pairs of metacentrics and one pair of submetacentric. Bleached DAPI Band analysis revealed a heterochromatin region, covering 28.6% to 50.4% each chromosomes. 5S and 45S rDNA sequences were located on two and three pairs of chromosomes, respectively. The centromere retrotransposon of Brassica (CRB) is a major component in Brassica related species that has been maintained as a common centromere component. CRB signals were detected on the centromere and pericentromeric region of R. sativus 'Wonkyo 10039' and three basic Brassica species (B. rapa, B. nigra, and B. oleracea). These results will provide a valuable background for physical mapping and elucidation of the evolutionary relationship among the Brassica related species.

Changes of Nitrifying Bacterial Populations in Anaerobic-Anoxic-Oxic Reactors (혐기-무산소-호기 반응조내 질화세균군의 변화)

  • Park, Jong-Woong;Lee, Young-Ok;Go, Jun-Heok;Ra, Won-Sik;Lim, Uk-Min;Park, Ji-Eun
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.2
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    • pp.138-144
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    • 2005
  • This study was carried out to investigate the changes of nitrifying bacterial populations including Nitrosomonas sp. and Nitrobacter sp. in $A^2/O$ pilot plant with the configuration of anaerobic-anoxic-oxic reactors. The suspended nitrifying bacterial populations in mixed liquor and those of attached populations on granular carrier surface made by molded waste tire were analyzed by Fluorescent in situ Hybridization(FISH) method. The nitrification rate of a pilot plant showed the value of $1.97{\sim}2.98\;mg\;N/g$ MLVSS hr. The ratios of suspended ammonia oxidizer including Nitrosomonas sp. (NSO) to total bacteria in each reactor were oxic < anoxic < anaerobic. On the contrary, the ratios of suspended nitrite oxidizer including Nitrobacter sp. (NIT) were anaerobic < anoxic < oxic. The thickness, dry density and mass of the attached biomass on granular carriers were $180{\sim}188\;{\mu}m$, $38.5{\sim}43.9\;mg/cm^3$, $29.4{\sim}32.5\;mg/g$, respectively. Also, the ratios of attached nitrifier to total bacteria on granular carriers were similar regardless of ammonia/nitrite-oxidizer (NSO; 3.2%, NIT; 2.8%) and very low compared to those(NSO; $22.8{\sim}28.4%$, NIT; $17{\sim}26%$) of suspended nitrifier.