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        검색결과 64

        44.
        2003.03 구독 인증기관 무료, 개인회원 유료
        본 연구는 xanthine(X)-xanthine oxidase(XO) system하에서 돼지 난자의 체외성숙과 체외수정에 대한 catalase의 영향을 검토하였다. 그 결과 돼지 난포난자가 X 또는 XO하에서 배양되었을 때, 난포난자의 성숙율은 다른 배양시간에도 불구하고 catalase 첨가 유무에 따른 유의적인 차이를 나타내지 않았다. 그렇지만, X-XO-catalase system하에서 배양한 경우 유의적으로 높은 성숙율을 얻었다(P<0.05). 퇴행난자의 비율은 배양기간이 늘어남에 따라 증가되었으며, 배양 120시간에서는 catalase 첨가시보다 무첨가시에 유의적으로 높았다. 다른 한편으로, 단위발생 난자들이 배양 72시간에 높은 비율로 관찰되었지만, 다양한 배양시간에서 catalase 첨가유무에 따른 차이는 발견되지 않았다. 또 다른 실험에서, 동결-응해된 돼지 정자가 체외수정을 위해 X-XO system으로 처리되었다. 난자투명대에 대한 정자침입율은 none (P<0.05), XO, X+XO하에서 체외수정시 catalase 무첨가시보다 첨가시에 높게 나타났다. 다른 한편으로, 돼지정자가 none, X, XO, X+XO로 처리되었을 때, lipid peroxidation은 catalase 첨가시보다 무첨가시에 높은 비율로 나타났으며, 그 결과 정자침입과 lipid peroxidation에서의 변화가 상반되는 양상을 보였다. 그렇지만, 모든 조건하에서 정자의 sulfhydry (-SH) group의 함량은 catalase 첨가시에 높게 측정되었다. 난자의 투명대에 대한 정자의 접착 정도는 salt-stored 돼지 난자에 대한 정자접착을 통해서 평가되었으며, control group의 경우 X, XO, X+XO group에 비해 높은 정자접착율이 관찰되었다. 그렇지만, catalase 첨가유무에 따른 유의적인 차이는 인정되지 않았다. 본 연구의 결과는 X-XO-catalase system에 대한 난포난자와 정자의 노출이 돼지에서의 체외성숙과 체외수정을 촉진시키는 것으로 생각된다.
        4,000원
        56.
        2013.07 서비스 종료(열람 제한)
        We investigated whether sound could alter gene expression in plants. Using a sound-treated subtractive library, a set of sound-responsive genes in plants was demonstrated through mRNA expression analyses. Of them, the rbcS and ald genes, which are light responsive, up-regulated their expression with sound treatment in both light and in dark conditions. This suggested that sound could be used as a gene regulator instead of light. When we analyzed ald gene expression using various single wavelengths, a significant increase in mRNA levels was found at 125 or 250 Hz but decreased at 50 Hz, indicating that the gene responded to sound in a wavelength-specific manner. To determine whether the ald promoter respond to sound, we generated transgenic rice plants harboring the chimeric gene consisting of a 1,506-bp promoter fragment of the ald gene fused to Escherichia coli GUS reporter gene. Analyses of mRNA expressison level of three independent transgenic lines sound-treated with 50 or 250 Hz for 4 h showed that the Gus gene expression in all three transgenic lines was up regulated by 250 Hz, but down regulated by 50 Hz. These results correlated with sound responsive mRNA expression pattern observed for the ald gene in rice plants, indicating that the 1,506-bp ald promoter confers sound-responsiveness on a reporter gene in transgenic rice plants. We also investigated whether sound waves could improve salt tolerance in rice seedling. The rice seedlings were sound treated with 800 Hz for 1hr, and then treated with 0, 75, 150, and 225mM NaCl for 3 days to observe changes in physiological and morphological aspects. Sound treatment seedlings resulted in enhanced salt stress tolerance, mainly demonstrated by the sound treated seedlings exhibiting of increased root relative water contents (RWC), root length and weight, photochemical efficiency (ratio of variable to maximum fluorescence, Fv/Fm), and germination rate under salt stress condition. This demonstrates that a specific sound wave might be used, not only to alter gene expression in plant, but also to improve salt stress tolerance.
        59.
        2003.09 서비스 종료(열람 제한)
        The high incidence of polyspermic fertilization is one of the major causes lowering the overall efficiency of porcine IVF. The common procedure for IVF involves the co-culture of both gametes in the medium drop, which increases sperm concentration and incidence of polyspermy. Therefore, the present study was carried out to increase the efficiency of porcine IVF by reducing polyspermy using a modified swim-up method. This method modifies conventional swim-up washing by placing oocytes directly at the time of washing. Sperm pellet was prepared in the tube and mature oocytes were placed on cell strainer with pore size (Falcon 2350) at the top of the tube. After insemination, the oocytes were stained for examination. Also, the developmental potential of fertilized embryos was measured to evaluate for the feasibility of this method. While having similar penetration rates in both methods (), there was a significant reduction of polyspermy in modified swim-up method () compare to the control ( (p<0.05). Subsequent culture showed higher rate of blastocyst formation in modified swim-up method (20.440.99%) than the control () (P<0.05), even though there was no significant difference. These results suggest that, by controlling the number of spermatozoa reaching the oocytes, porcine oocytes might be protected from polyspermy in vitro. Also, the developmental potential of the fertilized embryos using this method could be improved by increasing the pool of spermatozoa with better quality. Further optimization of the procedure required to implicate this method in routine porcine IVF.
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