• The Journal of the Petrological Society of Korea
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• v.10 no.3
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• pp.190-201
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• 2001

Isotope Dilution Mass Spectrometry(IDMS) is one of the analytical method which uses enriched isotope spikes and analyzes the abundance of element by comparison of the spectrum between spiked mass and non-spike mass. Especially, the Thermal Ion Mass Spectrometry with isotope dilution technique (in general ID-TIMS) is the most accurate method of the chemical analysis, which enables us to obtain the data better than 1% in accuracy and precision. In IDMS, enriched isotope spike is one of the most important factor in order to obtain the best data. For rare earth elements, in general, a mixture of /sup 138/La, /sup 142/Ce, /sup 145/Nd, /sup 149/Sm, /sup 151/Sm, /sup 151/Eu, /sup 157/Gd, /sup 163/Dy, /sup 167/Er, /sup 171/Yb, and /sup 176/Lu is used as composite spike. IDMS is very useful in geochronology and REE geochemistry. Especially, it is very effective in studying the “tetrad effect” of rare earth elements in natural samples.

• FLOWER RESEARCH JOURNAL
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• v.16 no.1
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• pp.12-16
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• 2008

This study was carried out to produce haploid plants to verify a systematic breeding program and genetic analysis. Effect of developmental stage of pollen grains and pre-treatment temperature on production of haploid plants was investigated. Microscopic investigation of the explants (Lilium Asiatic hybrid 'reamland' revealed that the length of flower bud at 23.0-24.9, 25.0-26.9, and 27.0-28.9 mm long coincided with tetrad, uninucleate, and binucleate, respectively. When the efficiency of the anther culture from microgametogenetic stages was tested, late uninucleate to early binucleate stage, having the length of 23.0 to 28.0 mm long flower bud, was the best. The frequencies of the callus induction and plant regeneration from the stage mentioned above were 17.8 and 6.7%, respectively. When calli were cultured on the MS medium containing picloram and zeatin at $25^{\circ}C$, shoots were obtained. Roots of regenerated plantlets were confirmed as haploid through an microscopic observation.

• Journal of Korean Society on Water Environment
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• v.27 no.6
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• pp.754-759
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• 2011

A sequencing batch reactor (SBR) was operated under different pH conditions to better understand the influence of pH to granulation in enhanced biological phosphorus removal systems. Granules from the SBR were also investigated using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Considerable decreases in the amount of phosphorus released per substrate provided under anaerobic conditions and the content of biomass polyphosphate under aerobic conditions were observed when pH was changed from 7.5 to 7.0, followed by 6.5. Aerobic granulation was also observed at pH 7.0. A number of bacteria with the typical morphological traits of tetrad-forming organisms (TFOs) were observed at pH 7.0, including large members of cluster. Filamentous bacteria were also there in large numbers. The occurrence and growth of granules were further enhanced at pH 6.5. A SEM analysis showed that the aerobic granules had a compact microbial structure with shaperical shape and morphologically consisted of aggregates of small coccoid bacteria and filamentous bacteria encapsulated by extracellular polymeric substance. The main material ions identified by EDX moreover revealed that the structural materials for polyphosphate in the granules include phosphorus, potassium and calcium. Therefore, these results strongly suggested that PAOs are a dominant population in the microbial community of the aerobic granules.

• Korean Journal of Microbiology
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• v.51 no.2
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• pp.181-185
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• 2015

Tho2/THOC2 is a subunit of the THO complex that plays important roles in mRNP biogenesis connecting transcription with mRNA maturation and export. A fission yeast, Schizosaccharomyces pombe, ortholog of Tho2/THOC2 was identified from the genome database. Tetrad analysis showed that the S. pombe tho2 is essential for growth. Repression or overexpression of the tho2 gene caused growth defect with elongated cells, abnormal DNA distribution, and accumulation of $poly(A)^+$ RNA in the nucleus. And the functional GFP-Tho2 protein is localized mainly in the nucleus. Yeast two-hybrid analysis showed that Tho2 interacted with Tex1, another subunit of THO complex. These results suggest that S. pombe Tho2 is also involved in mRNA export from the nucleus and is a component of THO complex.

• Korean Journal of Microbiology
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• v.53 no.1
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• pp.49-54
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• 2017

Sus1 / ENY2 is a tiny conserved protein that is involved in chromatin remodeling and mRNA biogenesis. Sus1 is associated to two nuclear complexes, the transcriptional coactivator SAGA and the nuclear pore associated TREX2. In fission yeast, Schizosaccharomyces pombe, ortholog of Sus1 / ENY2 was identified from the genome database. Tetrad analysis showed that the S. pombe sus1 is not essential for growth. However, deletion of the sus1 gene caused cold-sensitive growth retardation with slight accumulation of $poly(A)^+$ RNA in the nucleus. And the Sus1-GFP protein is localized mainly in the nucleus. Yeast two-hybrid analysis and co-immunoprecipitation experiment showed that Sus1 interacts with Sac3, another subunit of TREX2 complex. These results suggest that S. pombe Sus1 is also involved in mRNA export from the nucleus as a component of TREX-2 complex.

• Journal of Microbiology and Biotechnology
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• v.10 no.6
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• pp.776-783
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• 2000

Various alcohol yeast strains have been isolated from main mashes of Korean traditional liquors, and their genetic diversities were previously reported [23]. In this study, the strain SHY111, showing the highest alcohol production, was tested for its fermentation and sporulation characteristics. Additionally, its haploid cells were isolated and tested for their growth and fermentation patterns. The strain was identified as Saccharomyces cerevisiae based on its morphological and physiological characteristics. The sequences of the ITS(internal transcribed spacer) and 5.8S rDNA regions of S. cerevisiae SHY111 were found to be identical to those of S. cerevisiae that was obtained from through the yeast genome project. The maximum fermentation ratio obtained by the strain SHY111 (96.7%) was almost the same as that by S. cerevisiae Balyun No. 1 (96.5%) that was a little higher than that by S. cerevisiae KCCM11215(95.8%). The strain was induced for sporulation in a sporulation liquid medium using log phase cells grown in different types of pre-sporulation media, and its haploid cells were obtained by spore dissection using a micromanipulator. The majority of the spores formed a small colony on a YPD agar plate, and the haploid yeast cells derived from the strain SHY111 showed a variety of growth and alcohol fermentation patterns. It was proposed that the fermentation patterns were related to their growth phenotypes in the most haploid strains, but possible not in some strains.

• Korean Journal of Microbiology
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• v.48 no.2
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• pp.171-174
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• 2012

THOC1/Hpr1 is one subunit of THO complex that is an evolutionally conserved assembly involved in the mRNP packaging and mRNA export during transcription elongation. In fission yeast Schizosaccharomyces pombe, an ortholog (spHpr1) of THOC1/Hpr1 was identified based on sequence alignment. A deletion mutant in a diploid strain was constructed by replacing one of spHpr1-coding region with a $kan^r$ gene using one-step gene disruption method. Tetrad analysis showed that the sphpr1 is essential for growth. Over-expression of sphpr1 from strong nmt1 promoter caused no defects of growth and mRNA export. However, repression of the sphpr1 expression resulted in growth inhibition accompanied by accumulation of poly$(A)^+$ RNA in the nucleus. These results suggest that spHpr1 is involved in mRNA export from the nucleus to cytoplasm.

• Korean Journal of Microbiology
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• v.46 no.4
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• pp.401-404
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• 2010

Tho1 is a RNA-binding protein that assembles co-transcriptionally onto the nascent mRNA and is thought to be involved in mRNP biogenesis and mature mRNA export to cytoplasm in budding yeast. In fission yeast Schizosaccharomyces pombe, a homologue of THO1 (spTho1) was identified based on sequence alignment. A deletion mutant in a diploid strain was constructed by replacing one of spTho1-coding region with an ura4+ gene using one-step gene disruption method. Tetrad analysis showed that the spTho1 was not essential for growth. The spTho1 mutant did not show any defects of bulk mRNA export. However, over-expression of spTho1 from strong nmt1 promoter caused the growth defects and accumulation of poly(A)$^+$ RNA in the nucleus. These results suggest that spTho1 is involved in mRNA export from the nucleus to cytoplasm though it is not essential.

• Korean Journal of Microbiology
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• v.50 no.3
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• pp.249-253
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• 2014

THOC7/Mft1 is a member of the THO complex that is an evolutionally conserved assembly connecting transcription elongation with mRNP packaging and mRNA export. In fission yeast Schizosaccharomyces pombe, an ortholog (spThoc7) of THOC7/Mft1 was isolated by partial complementation of the lethality in synthetic lethal mutant, SLRsm1. A deletion mutant in a diploid strain was constructed by replacing one of spThoc7-coding region with an $ura4^+$ gene using one-step gene disruption method. Tetrad analysis showed that the spthoc7 is nonessential for growth. But the ${\Delta}thoc7$ null mutant showed slight defects of both growth and mRNA export. And the functional spThoc7-GFP protein is localized mainly in the nucleus. These results suggest that spThoc7 is also involved in mRNA export from the nucleus to cytoplasm.