• Applied Biological Chemistry
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• v.15 no.2
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• pp.163-168
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• 1972

Previously identified female pupae were X-irradiated with a dose of 1000r one day prior to moth transformation. Female mothes from irradiated and non-irradiated pupae were copulated with normal male ones and allowed to lay eggs. Fertilized eggs were collected at 6 intervals such as 5, 15, 45, 90 minutes, 12 and 40 hours after laying, and deep-freezed immediately after each collection until measurements. RNase activity and nucleic acid content were determined with each sample and following results were obtained. 1) It was proved to exist two RNases in silk worm eggs as in mammalian tissues, one active maximally at pH 5.8 and the other at pH 8.0, and the acid RNase activity was much higher than that of alkaline RNase. 2) The activity of acid and alkaline RNases increased remarkably during early development of the embryo of silk worm eggs, reaching the maximum activity at 45 minutes from laying time in non-irradiated group. There was no appreciable difference in two RNase activities for 45 minutes after laying in both control and irradiated groups, but the activity of acid and alkaline RNases in latter group was three times as much as that in former group, at 90 minutes from laying time and it was also found the acid RNase activity was 1.8 times higher than alkaline one in irradiated group. 3) The RNA-P content of control group increased considerably for initial 45 minutes, followed by a decline 45 minutes later with sight but steady increase thereafter. The RNA-P content of irradiated group, however, increased at initial 5 minutes, followed by a marked fall 90 minutes after laying, with no change thereafter. The DNA-P of control group showed a sharp increase for initial 45 minutes, followed by a decline 45 minutes later with no appreciable change thereafter, whereas that of irradiated group showed an increase at initial 15 minutes, followed by a sharp decline for following 45 minutes with a gradual increase thereafter. It was thus proved that the synthesis of nucleic acid in silk worm eggs was much suppressed by X-irradiation during early development of embryo. 4) The RNase activity varied in parallel with the RNA-P content in control group, but the RNA-P content in irradiated group was shown to be minimum value in concidence with the maximum activity of both RNases.

• The Journal of the Korean Society for Microbiology
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• v.35 no.5_6
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• pp.352-352
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• 2000

• Applied Biological Chemistry
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• v.15 no.3
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• pp.181-186
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• 1972

Wheat coleoptile sections were treated with either $1.5{\times}10^{-5}M$ ABA or $5×10^{-5}M$ IAA in vitro, the results may be summarized as follows, 1. The treatmert of IAA decreased the level of high molecular weight RNA F2 and F3 but that with ABA increased the F4 level. 2. IAA caused an increased activity of G2 isozyme, while ABA suppressed the activity of G3 isozyme. 3. The results may suggest that there may exist common effects of IAA and ABA on RNA and RNase. 4. The latent RNase activity caused by SH blocking reagent (p-hydroxymercury benzoate, Pb et al) was not observed.

• Food Science of Animal Resources
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• v.31 no.2
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• pp.158-165
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• 2011

A sensitive reverse transcriptase-PCR (RT-PCR) method to detect viable Escherichia coli O157:H7 in milk was established. The primer sets were designed based on the nucleotide sequences of the rfbE (per) and wbdN genes in the O157 antigen gene cluster of E. coli O157:H7. RT-PCR using five different primer sets yielded DNA with sizes of 655, 518, 450, and 149-bp, respectively. All five of the E. coli O157:H7 strains were detected by RT-PCR, but 11 other bacterial species were not. The sensitivity of RT-PCR was improved by adding yeast tRNA as a carrier to the crude RNA extract. The RT-PCR amplifying the 149-bp DNA fragment was the most sensitive for detecting E. coli O157:H7 and the most refractory to the bactericidal treatments. Heat treatment at $65^{\circ}C$ for 30 min was the least inhibitory of all bactericidal treatments. Treatment with RNase A strongly inhibited the RT-PCR of heated milk but not unheated milk. This study described RT-PCR methods that are specific and sensitive with a detection limit of 10 E. coli O157:H7 cells, and showed that pre-treating milk samples with RNase A improved the specificity to detect viable bacteria by RT-PCR.

• The Korean Journal of Zoology
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• v.20 no.1
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• pp.9-18
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• 1977

RNA was extracted from the eggs of Xenopus laevis to do preliminary experiments before testing the possibility that if RNase resistant RNA molecules exist in the amphibian egg. Chromatography on Sephadex G-100 column indicated 3 peaks consistently. Only high molecular weight RNA species eluted in the first peak were labeled in vitro using $^{3}H$-dimethyl sulfate to eliminate the possible contribution of base paired oligonucleotides from tRNA. By this method, high specific activity could be obtained and the attached methyl groups were quite stable.

• Proceedings of the Zoological Society Korea Conference
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• 1998.10b
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• pp.284.1-284
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• 1998

No Abstract, See Full Text

• Parasites, Hosts and Diseases
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• v.55 no.4
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• pp.451-455
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• 2017

Echinostoma cinetorchis is an oriental intestinal fluke causing significant pathological damage to the small intestine. The aim of this study was to determine a full-length cDNA sequence of E. cinetorchis endoribonuclease (RNase H; EcRNH) and to elucidate its molecular biological characters. EcRNH consisted of 308 amino acids and showed low similarity to endoribonucleases of other parasites (<40%). EcRNH had an active site centered on a putative DDEED motif instead of DEDD conserved in other species. A recombinant EcRNH produced as a soluble form in Escherichia coli showed enzymatic activity to cleave the 3'-O-P bond of RNA in a DNA-RNA duplex, producing 3'-hydroxyl and 5'-phosphate. These findings may contribute to develop antisense oligonucleotides which could damage echinostomes and other flukes.

• Archives of Pharmacal Research
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• v.22 no.6
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• pp.542-548
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• 1999

The UL47 gene (b 60390-b 60388) located in the unique long region of the human cytomegalovirus (HCMV) AD169 strain genome was analyzed RNA mapping. Northern blot analysis showed that the UL47 gene was expressed at late times after infection (72 h postinfection). The 9.7-kb transcript was expressed in the infected cells but not in phosphonoformate-treated cells at 72 hpi, indicating that the UL47 gene was only expressed at late times after infection. To map the 5'-end and 3'-end of UL47 transcripts, primer at late times after infection. To map the 5'-end and 3'-end of UL47 transcripts, primer extension and RNase protection analysis were performed. Primer extension analysis revealed that the transcription initiation site of UL47 was located in 27 bp downstream (b 60323) of the TATA box motif. The sizes of UL47 ORF (approximately 2.9-kb) and UL48 ORF (approximately 6.7-kb) deduced from computer sequence analysis suggest that the expressed 9.7-kb transcript of UL47 uses the 3'-end polyadenylation signal of Ul48. The result of RNase protection determined that the 3'-end of UL47 RNA utilized the 3'-end polyadenylation signal of UL48, which is located in HCMV genome b 70082.

• Proceedings of the Zoological Society Korea Conference
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• 1996.10a
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• pp.233.2-233
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• 1996

No Abstract, See Full Text

• Journal of Plant Biology
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• v.37 no.3
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• pp.349-355
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• 1994

Viral RNA was extracted from a purified orchid strain of tobacco mosaic virus (TMV-O) from Cymbidium "Grace Kelly". Polyadenylated viral RNAs were primed with Not I-oligo (dT) primer-adapter. First-strand cDNAs were reversely transcribed by Moloney murine leukaemia virus reverse transcriptase (RNAse H-), and then second-strand cDNAs were synthesized by RNase H and DNA polymerase I. The resulting double-stranded cDNAs were ligated into pSPORT1 vector and transformed into competent E. coli strain JM109 cells. The size of cDNAs within the recombinant plasmids was ranging from 0.9 to 3.9 kb. Among the selected clones, pTMO-0205 and -0210 covered the 3' half and the 5' half of the viral genomic RNA, respectively, which were covering more than 99% of the viral genemo size based on sequencing analysis. Two cDNA fragments which were 3.1 kb BamHI and NotI fragement released from pTMO-0.205 and 3.3 kb SalI and BamHI fragment released from pTMO-0210 were ligated with T4 DNA ligase. The clone was almost entire length, lacking only 31 nucleotides from the 5' terminus based on the sequencing result. This method was shown to be efficiently applicable to other plant viral gnomic RNA for the construction of cDNA.n of cDNA.