감태 (Ecklonia cava)는 다년생 대형갈조류로써 활용성이 매우 높은 것으로 알려졌다. 이 연구는 감태의 대량 생산을 위한 실내 배양 조건 확립을 위해서 계절과 질소원 종류에 따른 감태 포자체의 생장과 생화학적 반응을 조사하였다. 제주도 서귀포 해역에 생육하는 감태를 계절별로 채집하여 계절별 수온조건 (봄 17°C, 여름 25°C, 가을 21°C 와 겨울 15°C)과 4가지 영양염 조건 [대조구 (control), 100 μM NH4 +를 넣은 실험구 (NH), 100 μM NO3 -를 추가한 실험구 (NO), 50 μM NH4 +와 50 μM NO3 -를 함께 넣은 실험구 (NHNO)]에서 배양하여 엽체의 생체량과 면적 변화에 따른 생장률, 질산환원효소 활성도와 광합성 색소 함량을 조사하였다. 감태의 생장은 뚜렷한 계절 변화를 나타냈고, 무게와 면적과의 상관성은 계절별로 차이를 보였다. 무게와 면적의 일일생장률은 겨울에 최고 값 (5.8±0.5와 6.6± 0.5% day-1)을 보였고, 여름에 최저값 (2.2±0.2와 3.0± 0.3% day-1)을 나타냈다. 엽체의 일일생장률은 NH와 NO 실험구에서 가장 높았으며 NHNO 실험구에서 중간 값 그리고 대조구에서 가장 낮은 값을 보였다. 감태의 질산환원 효소 활성도는 계절적으로 유의한 차이를 나타났으며, 대조구에서 가장 높고 (1.32±0.10 μmol NO2 - g-1 dry weight h-1), NH 실험구에서 가장 낮았다 (0.25±0.02 μmol NO2 - g-1 dry weight h-1). 엽체 내 광합성 색소의 함량은 대조구에서 가장 낮고 NHNO 실험구에서 가장 높았다. 본 연구 결과는 감태 배양을 위한 배양액을 제작 시, 단일 종류의 질소원으로 제작하는 것이 생장률을 향상시킨다는 것을 보여주었으며, 실내배양에 따른 최적 질소원 종류를 결정하는 데 중요한 기초자료를 제공할 것이다.

Seagrasses, sea flowering plants, comprise approximately 60 species globally and are often called ‘ecosystem engineers’ because they create their own habitats by modifying the surrounding environments, which provide coastal zones with a number of crucial ecosystem services. Zostera marina (the common name ‘eelgrass’) is one of the seagrass beds-forming species distributed widely in northern hemisphere including the Korean coast, which plays a pivotal role in ecosystem as a primary producer and a nursery habitat or refuge for other marine organisms. However, due to global climate change and anthropogenic activities such as reclamation and dredging, there has recently been a drastic decline in population sizes of Z. marina in Korea. In order to develop effective conservation and restoration management programs of Z. marina populations, it would be helpful to consider all biological aspects of this species such as genetic characteristics as well as ecological and physiological features. This study first provides information on genetic diversity and genetic structure of Jeju Island and Namhae populations of Z. marina, which will contribute to the establishment of appropriate conservation and restoration management plans for future persistence of this species. Using six microsatellite markers, we investigated the level of genetic diversity and genetic structure among 10 geographic populations of Z. marina inhabiting Jeju Island (Hamdeok, Tokki-seom, Sungsan, Woljeong, Ojo) and Namhae (Gamak bay, Jindong bay, Nampo, Anggang bay, Geoje) on the southern coast of Korea. The level of genetic diversity within Jeju populations (mean allelic richness [AR]: 1.57 ~ 3.09) was found to be significantly lower than Namhae populations (AR: 3.09 ~ 4.29) (Mann-Whitney U-test, P < 0.05). These findings suggest that effective population sizes (Ne) of Jeju populations are generally smaller than those of Namehae populations. Within Jeju Island, Hamdeok population had the smallest population size (coverage: 138 m2) and the lowest genetic diversity (AR: 1.57), while Ojo population had the largest population size (coverage: 275,736 m2) and the greatest level of genetic diversity (AR: 3.09). Hamdeok population showed evidence of genetic bottleneck. These results again suggest that Ne of Jeju populations is generally low (except Ojo population). Among Jeju populations, all pair-wise comparisons of FST values (i.e., degree of genetic differentiation) were highly significant (FST = 0.0612 ~ 0.7168, P < 0.001) despite Jeju populations that were geographically closely located, indicating that these local populations are genetically divergent, probably due to a lack of gene flow among the populations. The observed strong population structure was substantiated by evidence that five genetic clusters are most likely, based on population assignment test (STRUCTURE). The Mantel test showed a positive relationship between genetic distance (FST) and geographic distance (km) across all the populations sampled (R2 = 0.4118, P < 0.05), suggesting that our data follow Isolation By Distance (IBD) model. Woljeong population revealed the highest level of FST values compared to other populations within Jeju Island in IBD. STRUCTURE and factorial correspondence analysis (FCA) further showed that some Woljeong individuals included genotypes of Namhae populations. Population size of Woljeong (coverage: 310m2) was approximately 50 % smaller than that of Sungsan (coverage: 841m2); however, extent of its genetic diversity (AR: 2.39) was even higher than that of Sungsan population (AR: 1.77). We speculated that Woljeong population underwent a transplantation from Namhae populations with relatively higher level of genetic diversity. FST values within Namhae populations were relatively lower (compared to within Jeju Island) despite the populations that were geographically more distant. It means that level of gene flow is higher among Namhae populations than among Jeju populations. Z. marina is known to have different life histories by water depth. In subtidal zone (deep water depth) populations predominantly undertake sexual reproduction through seeds such as annual life history, whereas those of intertidal zone (shallow water depth) undertake both sexual and asexual reproductions through horizontal rhizomes i.e., perennial life history. STRUCTURE analysis showed no clear differences between shallow and deep populations at Namhae, but some FST values were statistically significantly different despite their low values. For Geoje population sampled in 2005, intertidal and subtidal populations were not significantly different (FST = 0.0045, P = 0.033), but these populations sampled in 2015 showed a significant difference (FST = 0.0328, P < 0.001). It means that genetic structure of Geoje has been changed over the 10 year period between shallow and deep populations. Overall, the Jeju and Namehae populations analyzed in the current study have relatively low levels of genetic diversity and distinct genetic compositions, which warns the message that this ecologically important species should be conserved separately in the local populations and with high priority. We propose that future conservation and restoration plans for seagrasses should consider genetic characteristics particularly because a close relationship between genetic diversity and ecological performance in marine species has been well documented.

It has been reported that light-emitting diodes(LED) can be used in the treatment of oral diseases. Although bio-stimulatory effects of LED irradiation such as promotes stimulation of wound healing have been well known, there are few reports about molecular mechanism associated with cell cycle by LED irradiation. The purpose of present study was to examine the molecular event in cell cycle of LED irradiation on primary human gingival fibroblast(hGF) in vitro. The source of light for irradiation was a continuous-wave LED emitting at a wavelength of 635nm, and manufactured that energy density was 5mW/cm2 on sample surface. The hGF were irradiated for 1 hour at 37℃ in 5% CO2 humidified chamber. Experimental samples were acquired at 0 (right after irradiation), 8 and 24 hour after irradiation. To investigate the molecular mechanisms associated with cell cycle, growth phase was determined by flow cytometry and mRNA expression of cyclin A, cyclin B, cyclin D1, cyclin E, cdc2, PCNA, p18, p27, p21, and p53 were determined by real time RT-PCR. Flow cytometric analysis demonstrated the percentage of cells in the G1 and S phase were decreased, but the G2 phase increased, which showed cells irradiated by LED were transitioned from S to G2 phase. For mRNA expression, cyclin B, cdc2, PCNA and p53 were increased at 0 hour after irradiation, and most of cell cycle molecules were increased at 8 hour after irradiation. At 24 hour after irradiation, cyclin A, cyclin E, PCNA and p18 were increased. Taken together, LED irradiation induced proliferation of hGF cells through transition from S to G2 phase.

The purpose 01' pl'esent study was to examine the molecular events in apoptosis by CoCl2, mimicking hypoxic cond ition and recovering effects by LED ir l'adiation on Human SH-SY5Y neuroblastoma cells The SOUl'ce 0 1' light for ir l'adiation was a continuous-wave LED emitting at a wavelenl양h of 590 nm, and manufactured that ene rgy density was 5 mW!cm2 on sample surface, After ir l'adiation, cell viabi lity was measured with BrdU , cell morphol ogy was examined with Diff- Quik staining, cell signaling was monitored with various apoptosis-related molecules using RNase Pl'otection Assay(RPA) , W11en treated with CoC12, apoptotic induction was found in the SH-SY5Y cells in a concentration-dependent and time-dependent manner , Diff-Quik s taining was revealed that DNA fragmentation re presented apoptosis was examined in CoC12-tl'eated group, Moreover, RPA assay of SH-SY5Y cclls lIs ing val'iolls apoptosis-related molecllles showed that the apoptotic cell population was mcreased J-loweve. there was sorne signifïcant change in LED irradiatied cells aftel' treatement of CoC12 The main mechanism for Lhese a poptosis appearecl to be mito c hondriεt - m ecliated pathway, such as cytochrome- c‘ caspase-9, caspase-3, pro-apototic protein ßax, anti-apototic protein Bcl-2, and death receptor• mediated pathway, such as Fas, cas pase- 8, a ncl TNFRl These results demonstrate that CoCI2 induce apoptosis in SH-SY5Y via different dual apop tosis pathway through death receptor pathway as well as mitochondria- dependent pathway and LED irradiation can recl llces the CoCl2-induced apoptosis by blocking their internal signaling pathway