• 생명과학회지
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• 제22권5호
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• pp.681-686
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• 2012

빛이 굴중성과 뿌리 생장에 미치는 영향을 알아보기 위해 Arabidopsis phytochrome mutant를 이용하여 뿌리 생장과 굴중성 반응을 측정하였다. $PhyA$의 뿌리 생장은 white light를 제외한 모든 빛 조건에서 WT와 비교하여 촉진되었다. 특히 red light에서 키웠을 때 다른 mutant와는 달리 뿌리 생장이 촉진되었다. 반면에 phyB는 모든 빛 조건에서 키웠을 때 뿌리 생장이 억제되었으며, 특히 double mutant인 $phyAB$는 white light와 red light에서 키웠을 때 뿌리 생장이 가장 많이 억제되었다. $PhyA$의 굴중성 반응은 far-red light에서 키웠을 때를 제외하고 모든 빛 조건에서 키웠을 때 WT와 비교하여 촉진되었다. 한편 $phyAB$는 모든 조건에서 모두 굴중성 반응이 억제되었다. Ethylene 생합성을 조절하는 효소인 ACS transcript 수준은 white light와 red light에서 키웠을 때 $phyA$가 높게 나타났으며, far-red light에서 키웠을 때는 $phyA$의 transcript 수준이 억제되었다. 결론적으로 뿌리 생장과 굴중성 반응은 $phyB$의 $P_{fr}$에 의해 조절된다.

• 센서학회지
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• 제11권2호
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• pp.84-92
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• 2002

국소 광적응 기능을 가지는 윤곽검출용 시각칩을 픽셀수 $32{\times}32$의 방사형 구조로 CMOS 공정기술을 이용하여 설계 및 제조하였다. 생체의 망막은 넓은 범위의 입력 광강도에 대해서 물체의 윤곽을 검출할 수 있다. 본 연구에서는 시세포, 수평세포, 쌍극세포로 이루어진 망막의 윤곽검출 기능을 모델링하여 윤곽검출용 인공시각칩을 설계하였다 국소 광적응을 위해 입력 광강도에 따라 수용야의 크기를 국소적으로 바뀌게 하였다. 아울러 단위셀을 방사형으로 배치함으로써 영상데이터의 양을 감소시킴과 동시에 칩의 중심부분으로 갈수록 해상도가 높아지도록 설계하였다. 설계된 칩은 $0.6\;{\mu}m$ double-poly triple-metal 표준 CMOS 공정기술을 이용하여 제조되었으며, HSPICE 시뮬레이션으로 성능을 최적화 시켰다.

• 한국환경농학회지
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• 제39권4호
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• pp.312-318
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• 2020

BACKGROUND: Photoreversibility, a reversion of the inductive effect of a brief red light pulse by a subsequent far red light pulse, is a property of photo responses regulated by the plant photoreceptor phytochrome B. Plants use photoreceptors to sense photo signal and to adapt and modify their morphological and physiological properties. Phytochrome recognizes red light and far red light and plays an important role in regulating plant growth and development. METHODS AND RESULTS: The reversal responses of growth and fruiting characteristics were investigated to increase the yield of oriental melon (Cucumis Melo L. var. Kumsargakieuncheon) by means of controlling light quality in a plastic house. Red (R:660nm) and far red (FR:730nm) lights were subsequently irradiated on the whole stems and leaves of the oriental melon plant during growing periods, using red and far red LEDs as light sources, from 9:00 PM daily for 15 minutes. The intensities of R and FR light were 0.322-0.430 μmol m-2s-1 and 0.250-0.366 μmol m-2s-1, respectively. Compared to R light irradiation, combination of R and FR light irradiation increased the length of internode, number of axillary stems, number of female flowers, and fruit number of oriental melons. The results of treatment with R were similar to R-FR-R light irradiation in terms of length of internode, number of axillary stems, number of female flowers, and number of fruits. When FR treatment was considered, R-FR and R-FR-R-FR light irradiation had similarities in responses. These reversal responses revealed that oriental melon showed a photoreversibility of growth characteristics, flowering, and fruiting. CONCLUSION: These results suggested the possibility of phytochrome regulation of female flower formation and fruiting in oriental melon. The fruit weight of the oriental melon was the heaviest with the R light irradiation, while the number of fruits was the highest with the FR light. With the FR light irradiation, the fruit weight was not significantly higher compared to that of the control. Meanwhile, the yield of oriental melon fruits increased by 28-36% according to the intensities of the FR light due to the increases of the number of fruits.

• 한국동물생명공학회지
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• 제37권4호
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• pp.292-297
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• 2022

Direct injection of CRISPR/Cas9 into zygotes enables the production of genetically modified nonhuman primates (NHPs) essential for modeling specific human diseases, such as Usher syndrome, and for developing novel therapeutic strategies. Usher syndrome is a rare genetic disease that causes loss of hearing, retinal degeneration, and problems with balance, and is attributed to a mutation in MYO7A, a gene that encodes an uncommon myosin motor protein expressed in the inner ear and retinal photoreceptors. To produce an Usher syndrome type 1B (USH1B) rhesus macaque model, we disrupted the MYO7A gene in developing zygotes. Identification of appropriately edited MYO7A embryos for knockout embryo transfer requires sequence analysis of material recovered from a trophectoderm (TE) cell biopsy. However, the TE biopsy procedure is labor intensive and could adversely impact embryo development. Recent studies have reported using cell-free DNA (cfDNA) from embryo culture media to detect aneuploid embryos in human in vitro fertilization (IVF) clinics. The cfDNA is released from the embryo during cell division or cell death, suggesting that cfDNA may be a viable resource for sequence analysis. Moreover, cfDNA collection is not invasive to the embryo and does not require special tools or expertise. We hypothesized that selection of appropriate edited embryos could be performed by analyzing cfDNA for MYO7A editing in embryo culture medium, and that this method would be advantageous for the subsequent generation of genetically modified NHPs. The purpose of this experiment is to determine whether cfDNA can be used to identify the target gene mutation of CRISPR/Cas9 injected embryos. In this study, we were able to obtain and utilize cfDNA to confirm the mutagenesis of MYO7A, but the method will require further optimization to obtain better accuracy before it can replace the TE biopsy approach.