• 한국약용작물학회지
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• 제8권1호
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• pp.14-20
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• 2000

인삼조직배양에서 배양환경 조절방법의 필요성을 검토코자 생장조절물질 IBA, BA, GA 각 $3mg/\;{\ell}$ 첨가한 MS 배지에 $CO_2(2500ppm)$를 강제 통기방식에 의해 기내에 처리하여 기관분화 유형별로 특성을 조사하였던 바 결과를 요약하면 다음과 같다. 저장종자의 분화능은 저온처리 60일 종자에서 적출한 배에 비하여 80일정도 저온처리한 성숙된 배의 자엽조직이 양호하였다. 기관발생 유형에서 $CO_2$처리 효과는 부정아 형성보다 shoot primordium 의 생장과 발달에 현저한 효과가 있었고 1개의 배로부터 shoot primordium 을 통해 수백 개의 신초분화가 가능하였다. 배발생 유형에서 $CO_2$처리는 무처리에 비해 indirect somatic embryo 분화 모두에 효과가 있었다. Indirect somatic embryo는 대체로 유관속 중심주와 상배축이 미분화된 관계로 신초가 분화 생장하지 못하였다. 그리고 direct somatic embryo는 자엽 이변의 하단부에서 분화 발달하였고 지상부와 지하부 그리고 잠아를 갖는 완전한 식물체로 생장하였다.

• 한국동물생명공학회지
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• 제38권3호
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• pp.143-150
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• 2023

Background: The successful production of superior or transgenic offspring from in vitro produced embryos in cattle relies heavily on the quality of blastocyst stage embryos. In order to enhance the developmental competency of these embryos, a novel culture method was devised. Methods: This study utilized stem cell culture medium (SCM) from hESCs as a supplement within the culture medium for bovine in vitro produced embryos. To gauge the efficacy of this approach, in vitro fertilized embryos were subjected to culture in CR1aa medium enriched with one of three supplements: 0.3% BSA, 10% FBS, or 10% SCM. Results: The blastocyst development and hatching rates of one-cell zygotes cultured in CR1aa medium supplemented with SCM (23.9% and 10.2%) surpassed those cultured in CR1aa medium supplemented with BSA (9.3% and 0.0%) or FBS (3.1% and 0.0%) (p < 0.05). Furthermore, post-zygotic gene activation, cleaved embryos cultured in CR1aa medium supplemented with SCM (57.8% and 34.5%) exhibited notably higher rates (p < 0.05) compared to those cultured with BSA (12.9% and 0.0%) or FBS (45.7% and 22.5%) supplementation. Furthermore, the microinjection of SCM into the cytoplasm or pronucleus of fertilized zygotes resulted in elevated blastocyst development and hatching rates, particularly when the microinjected embryos were subsequently cultured in CR1aa medium supplemented with SCM from the 8-cell embryo stage onwards (p < 0.05), in contrast to those cultured with FBS supplementation. Conclusions: In conclusion, this study conclusively demonstrated that the incorporation of SCM into the culture medium significantly enhances the developmental progress of preimplantation embryos.

• Journal of Plant Biotechnology
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• 제33권4호
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• pp.243-248
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• 2006

A optimal procedure for plant production via repetitive secondary somatic embryogenesis in Tilia amurensis is described. Somatic embryos were induced directly from the culture of zygotic embryos on medium with 1.0 mg/l 2,4.-D. Repetitive secondary somatic embryos formed on the surface of the cotyledons and hypocotyls except for the radicles when explants of somatic embryos were cultured on medium with 4.0 mg/l 2,4-D. The highest frequency of secondary embryo-genesis was obtained in the cotyledons (90%) and hypocotyls(83.33%) on MS medium with 1.0 mg/L 2,4-D. The average number of secondary embryos per explant was 25.74 in cotyledon and 24.92 in hypocotyl. When the cotyledon and hypocotyl segments from somatic embryos at different developmental stages were cultured on MS medium with 1.0 mg/L 2,4-D, the highest frequency of secondary embryogenesis was obtained from late cotyledonary secondary embryos. Somatic embryos were transferred to MS basal medium and then they germinated within 2 to 4 weeks of culture. Germinated somatic embryos grew normally into plantlets on WPM medium, producing new shoots. The converted plantlets were acclimatized on artificial soil mixture. These results indicate that the repetitive secondary somatic embryogenesis in T amurensis can offer the possibility to use in vitro culture system for the micropropagation.

• Journal of Plant Biotechnology
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• 제37권4호
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• pp.343-356
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• 2010

Plant micropropagation techniques include bud cultures using apical or axillary buds, organogenesis through callus culture or adventitious bud induction, and somatic embryogenesis. In Korea Forest Research Institute (KFRI), the first tissue culture trial in woody plant was initiated from the bud culture of hybrid poplars (Populus alba x P. glandulosa) in 1978. Since then several mass propagation techniques have developed from conifer and hardwood species, resulting in allowing practical application to Poplars, Birches and some oak species. In addition, useful micropropagation and genetic resources conservation techniques were established in some rare and endangered tree species including Abeliophyllum distichum. Among various in vitro propagation techniques, somatic embryogenesis is known to be the most efficient plant regeneration system. Since the first somatic embryo induction was reported in Tilia amurensis by KFRI in 1986, various protocols for direct or indirect somatic embryogenesis systems have developed in conifer and hardwood species including Larix leptolepis, Pinus rigida x P. taeda F1, Kalopanax septemlobus and Liliodendron tulipifera, etc. However, most of these technologies have been developed using juvenile tissues, i.e. immature zygotic embryos or mature embryos. Therefore it has been difficult to directly application to tree breeding program due to their unproven genetic background. Recently remarkable progresses and new approaches have been achieved in mature tree somatic embryogenesis. In this article we reviewed several micropropagation techniques, which have been mainly developed by KFRI and recent international progresses.

• 한국산림과학회지
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• 제103권1호
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• pp.72-79
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• 2014

낙엽송의 성숙배로부터 최대 부정아 유도는 LP배지에 1.0 mg/L zeatin이 첨가된 처리구(76.1%)였으며, 2 mm 이상의 신초생장을 위한 효과적인 처리구는 Litvay(LM)배지에 0.5 mg/L zeatin(75.2%)을 첨가하거나, 혹은 Quoirin & Lepoivre(LP)배지에 2.0 mg/L zeatin(70.2%)에서 각각 나타났다. 배지의 염류함량을 반으로 줄인 부정아 유도 시험에서는 1/2LP배지에 1.0(83.3%) 혹은 2.0 mg/L(81.7%) zeatin을 첨가한 처리구에서 높은 유도율을 보였으나, 2 mm 이상의 신초생장을 위한 효과적인 처리구는 1/2LM배지에 1.0 mg/L zeatin(66.7%)에서였다. 배지의 염류함량을 반으로 줄인 부정아 유도 시험에서는 1/2LP배지에 1.0(83.3%) 혹은 2.0 mg/L(81.7%) zeatin을 첨가한 처리구에서 높은 유도율을 보였으나, 2 mm 이상의 신초생장을 위한 효과적인 처리구는 1/2LM배지에 1.0 mg/L zeatin(66.7%)에서였다. 그리고 1.0 mg/L zeatin처리구에서 2주배양 후 1.0 mg/L thidiazuron(TDZ) 처리구로 2주간 배양할 때 가장 높은 52.9%의 부정아 유도율을 보였으나 평균 부정아 유도수는 낮게 나타났다. 부정아유도를 위한 에틸렌활성제 혹은 억제제 첨가시험에서는 최대 부정아 유도율은 1.0 mg/L zeatin+2.0 mg/L MGBG(methylglyoxal bis-[guanylhydrazone])가 첨가된 처리구(34.6%) 였으며, 평균 최대 부정아 유도수는 1.5개를 보인 1.0 mg/L zeatin+2.0 mg/L $CoCl_2$ 처리구에서 나타났다.

• 식물조직배양학회지
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• 제24권2호
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• pp.107-112
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• 1997

본 연구는 미나리의 배발생 캘러스를 배양하여 정상적이고 균일한 형태의 체세포 배를 대량 생산할 수 있는 조건을 구명하고, 생산된 체세포배를 종묘로 이용하기 위한 기초연구로 실시하였다. 배발생 캘러스를 생장조절제, 당, 질소원등을 농도별로 첨가한 MS배지에 현탁배양한 결과는 아래와 같다. 배발생 캘러스를 생장조절제가 첨가되지 않은 액체배지에 현탁배양하면 배발생 세포괴 및 체세포 배가 왕성하게 증식되었다. 구형단계의 배를 IBA와 NAA를 첨가한 배지에 현탁배양하면 배발생 세포괴의 증식과 함께 배의 발달도 진행됐으나, 2,4-D가 첨가된 배지에서 배양하면 배발생 세포괴 및 세포만 증식하고 배의 발달은 진행되지 많았다. 질소원의 종류에 따른 배발생 세포괴의 생장 발육상태에서 $\textrm{KNO}_3$와 $\textrm{NH}_4\textrm{NO}_3$가 각각 20mM 첨가되었을 때 가장 좋았다. 유아 발달에는 $\textrm{NH}_4\textrm{NO}_3$가, 유근발달에는 $\textrm{KNO}_3$가 효과적이었다. 구형단계의 배를 sucrose가 3-6 % 첨가된 배지에 배양하면 발육이 좋았다. 구형단계의 배를 ABA가 첨가되지 않은 배지에 배양하면 하배축의 이상신장 및 다배현상이 일어나지만 ABA가 $10\mu\textrm{M}$ 첨가된 배지에 배양하면 하배축의 길이가 단축되고 이차배 발생도 현저히 감소하였다. 고체배지에 배발생캘러스를 계속 배양하여 다양의 구형배를 얻을 수 있고 이들을 생장조절제가 첨가되지 않은 배지에서 배양하면 종자 유내 식물체와 유사한 유식물을 얻을 수 있었다.

• 식물조직배양학회지
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• 제27권6호
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• pp.423-428
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• 2000

In 1997 when cloned sheep Dolly and soon after Polly were born, it had become head-line news because in the former the nucleus that gave rise to the lamb came from cells of six-year-old adult sheep and in the latter case a foreign gene was inserted into the donor nucleus to make the cloned sheep produce human protein, factor IX, in e milk. In the last few years, once the realm of science fiction, cloned mammals especially in livestock have become almost commonplace. What the press accounts often fail to convey, however, is that behind every success lie hundreds of failures. Many of the nuclear-transferred egg cells fail to undergo normal cell divisions. Even when an embryo does successfully implant in the womb, pregnancy often ends in miscarriage. A significant fraction of the animals that are born die shortly after birth and some of those that survived have serious developmental abnormalities. Efficiency remains at less than one % out of some hundred attempts to clone an animal. These facts show that something is fundamentally wrong and enormous hurdles must be overcome before cloning becomes practical. Cloning researchers now tent to put aside their effort to create live animals in order to probe the fundamental questions on cell biology including stem cells, the questions of whether the hereditary material in the nucleus of each cell remains intact throughout development, and how transferred nucleus is reprogrammed exactly like the zygotic nucleus. Stem cells are defined as those cells which can divide to produce a daughter cell like themselves (self-renewal) as well as a daughter cell that will give rise to specific differentiated cells (cell-differentiation). Multicellular organisms are formed from a single totipotent stem cell commonly called fertilized egg or zygote. As this cell and its progeny undergo cell divisions the potency of the stem cells in each tissue and organ become gradually restricted in the order of totipotent, pluripotent, and multipotent. The differentiation potential of multipotent stem cells in each tissue has been thought to be limited to cell lineages present in the organ from which they were derived. Recent studies, however, revealed that multipotent stem cells derived from adult tissues have much wider differentiation potential than was previously thought. These cells can differentiate into developmentally unrelated cell types, such as nerve stem cell into blood cells or muscle stem cell into brain cells. Neural stem cells isolated from the adult forebrain were recently shown to be capable of repopulating the hematopoietic system and produce blood cells in irradiated condition. In plants although the term$\boxDr$ stem cell$\boxUl$is not used, some cells in the second layer of tunica at the apical meristem of shoot, some nucellar cells surrounding the embryo sac, and initial cells of adventive buds are considered to be equivalent to the totipotent stem cells of mammals. The telomere ends of linear eukaryotic chromosomes cannot be replicated because the RNA primer at the end of a completed lagging strand cannot be replaced with DNA, causing 5' end gap. A chromosome would be shortened by the length of RNA primer with every cycle of DNA replication and cell division. Essential genes located near the ends of chromosomes would inevitably be deleted by end-shortening, thereby killing the descendants of the original cells. Telomeric DNA has an unusual sequence consisting of up to 1,000 or more tandem repeat of a simple sequence. For example, chromosome of mammal including human has the repeating telomeric sequence of TTAGGG and that of higher plant is TTTAGGG. This non-genic tandem repeat prevents the death of cell despite the continued shortening of chromosome length. In contrast with the somatic cells germ line cells have the mechanism to fill-up the 5' end gap of telomere, thus maintaining the original length of chromosome. Cem line cells exhibit active enzyme telomerase which functions to maintain the stable length of telomere. Some of the cloned animals are reported prematurely getting old. It has to be ascertained whether the multipotent stem cells in the tissues of adult mammals have the original telomeres or shortened telomeres.