• Title/Summary/Keyword: biology major

Search Result 2,061, Processing Time 0.027 seconds

Micromorphology and development of the epicuticular structure on the epidermal cell of ginseng leaves

  • Lee, Kyounghwan;Nah, Seung-Yeol;Kim, Eun-Soo
    • Journal of Ginseng Research
    • /
    • v.39 no.2
    • /
    • pp.135-140
    • /
    • 2015
  • Background: A leaf cuticle has different structures and functions as a barrier to water loss and as protection from various environmental stressors. Methods: Leaves of Panax ginseng were examined by scanning electron microscopy and transmission electron microscopy to investigate the characteristics and development of the epicuticular structure. Results: Along the epidermal wall surface, the uniformly protuberant fine structure was on the adaxial surface of the cuticle. This epicuticular structure was highly wrinkled and radially extended to the marginal region of epidermal cells. The cuticle at the protuberant positions maintained the same thickness. The density of the wall matrix under the structures was also similar to that of the other wall region. By contrast, none of this structure was distributed on the abaxial surface, except in the region of the stoma. During the early developmental phase of the epicuticular structure, small vesicles appeared on wallecuticle interface in the peripheral wall of epidermal cells. Some electron-opaque vesicles adjacent to the cuticle were fused and formed the cuticle layer, whereas electron-translucent vesicles contacted each other and progressively increased in size within the epidermal wall. Conclusion: The outwardly projected cuticle and epidermal cell wall (i.e., an epicuticular wrinkle) acts as a major barrier to block out sunlight in ginseng leaves. The small vesicles in the peripheral region of epidermal cells may suppress the cuticle and parts of epidermal wall, push it upward, and consequently contribute to the formation of the epicuticular structure.

Molecular Phylogeny and Distribution of Far Eastern Oryzias latipes Based on Mitochondrial Cytochrome b Gene Sequence (미토콘드리아 cytochrome b 유전자 염기서열 분석에 의한 극동지역 송사리의 계통과 지리적 분포의 상관관계)

  • Eah, Jae-Yong;Yoo, Jeong-Ha;Kang, Tae-Wook;Kim, Moo-Sang;Kim, Chang-Bae
    • Korean Journal of Ichthyology
    • /
    • v.18 no.1
    • /
    • pp.12-19
    • /
    • 2006
  • To examine the relationship of geological distribution and phylogenetic tree of O. latipes in the Far East, we analyzed cytochrome b (cyt b) gene in the mitochondrial genome. In this study we employed the entire sequence of cyt b of 53 samples collected from nine Korean locations and 117 cyt b data retrieved from the GenBank. From 170 Oryzias latipes cyt b sequence data, 142 different haplotypes were identified and phylogenetic relationship was reconstructed based on the dataset. According to the phylogeny, haplotypes were divided into three major haplogroups A, B and C, and their relationships were well correlated to their distributional patterns. Haplogroup A which is widely distribute in the southern part of Korea is separated in the geographical distribution from the haplogroup B which is found from China to the western part of Korea. Haplogroup C is only found in Japan.

Seeing is Believing: Illuminating the Source of In Vivo Interleukin-7

  • Kim, Grace Yoon-Hee;Hong, Chang-Wan;Park, Jung-Hyun
    • IMMUNE NETWORK
    • /
    • v.11 no.1
    • /
    • pp.1-10
    • /
    • 2011
  • Interleukin-7 (IL-7) is an essential cytokine for T cells. However, IL-7 is not produced by T cells themselves such that T cells are dependent on extrinsic IL-7. In fact, in the absence of IL-7, T cell development in the thymus as well as survival of naive T cells in the periphery is severely impaired. Furthermore, modulating IL-7 availability in vivo either by genetic means or other experimental approaches determines the size, composition and function of the T cell pool. Consequently, understanding IL-7 expression is critical for understanding T cell immunity. Until most recently, however, the spatiotemporal expression of in vivo IL-7 has remained obscured. Shortage of such information was partly due to scarce expression of IL-7 itself but mainly due to the lack of adequate reagents to monitor IL-7 expression in vivo. This situation dramatically changed with a recent rush of four independent studies that describe the generation and characterization of IL-7 reporter mice, all utilizing bacterial artificial chromosome transgene technology. The emerging consensus of these studies confirmed thymic stromal cells as the major producers of IL-7 but also identified IL-7 reporter activities in various peripheral tissues including skin, intestine and lymph nodes. Strikingly, developmental and environmental cues actively modulated IL-7 reporter activities in vivo suggesting that IL-7 regulation might be a new mechanism of shaping T cell development and homeostasis. Collectively, the availability of these new tools opens up new venues to assess unanswered questions in IL-7 biology in T cells and beyond.

The Role of MicroRNAs in Regulatory T Cells and in the Immune Response

  • Ha, Tai-You
    • IMMUNE NETWORK
    • /
    • v.11 no.1
    • /
    • pp.11-41
    • /
    • 2011
  • The discovery of microRNA (miRNA) is one of the major scientific breakthroughs in recent years and has revolutionized current cell biology and medical science. miRNAs are small (19~25nt) noncoding RNA molecules that post-transcriptionally regulate gene expression by targeting the 3' untranslated region (3'UTR) of specific messenger RNAs (mRNAs) for degradation of translation repression. Genetic ablation of the miRNA machinery, as well as loss or degradation of certain individual miRNAs, severely compromises immune development and response, and can lead to immune disorders. Several sophisticated regulatory mechanisms are used to maintain immune homeostasis. Regulatory T (Treg) cells are essential for maintaining peripheral tolerance, preventing autoimmune diseases and limiting chronic inflammatory diseases. Recent publications have provided compelling evidence that miRNAs are highly expressed in Treg cells, that the expression of Foxp3 is controlled by miRNAs and that a range of miRNAs are involved in the regulation of immunity. A large number of studies have reported links between alterations of miRNA homeostasis and pathological conditions such as cancer, cardiovascular disease and diabetes, as well as psychiatric and neurological diseases. Although it is still unclear how miRNA controls Treg cell development and function, recent studies certainly indicate that this topic will be the subject of further research. The specific circulating miRNA species may also be useful for the diagnosis, classification, prognosis of diseases and prediction of the therapeutic response. An explosive literature has focussed on the role of miRNA. In this review, I briefly summarize the current studies about the role of miRNAs in Treg cells and in the regulation of the innate and adaptive immune response. I also review the explosive current studies about clinical application of miRNA.

Synthesis and Characterization of Catechol-Containing Biomimetic Mucoadhesive Polymers (카테콜 함유 생체모방 점막접착형 고분자의 합성 및 특성 연구)

  • Park, Dong Jin;Lee, Sang Jin;Lee, Sang Cheon
    • Polymer(Korea)
    • /
    • v.37 no.5
    • /
    • pp.625-631
    • /
    • 2013
  • Mucoadhesive property is the major function as an adhesive for medical devices, and therefore, these days many researches have conducted to develop polymers having this property. Recently, biomimetic technology has been used for developing mucoadhesive polymers. Among many technologies, mussel-inspired approaches have received noticeable attention because of its thread's strong adhesive characteristics. In this study, we synthesized mucoadhesive biomimetic polymers employing catechol structures which are abundant in mussel adhesive proteins, and their structures and molecular weights were characterized by using nuclear magnetic resonance spectroscopy and gel permeation chromatography. To evaluate in vitro mucoadhesive strength, the sheet type of the small intestinal porcine submucosa was prepared. Compared to commercial fibrin glue adhesives, catechol-containing mucoadhesive polymers showed enhanced adhesive strength. The study of adhesive strength with considering diverse factors, such as temperature, pressure, and oxidant amount indicated that mussel-inspired mucoadhesive polymer could be a promising candidate for an adhesive in various biomedical applications.

A Study on the Gymnodinium nagasakiense Red-Tide in Jinhae Bay of Korea (진해만의 Gymnodinium nagasakiense 적조에 관한 연구)

  • Lee, Jin-Hwan;Kwak, Hi-Sang
    • The Korean Journal of Ecology
    • /
    • v.9 no.3
    • /
    • pp.149-160
    • /
    • 1986
  • Relationship between the causative organi는 of red-tide and environmental factors had been ecologically dealt wtih. The surveys were conducted at seven station in Jinhae Bay from July to September 1981. The water temperature and salinity had wide range, i.e. 23.3~29.3$^{\circ}C$ and 19G.78~31.29$\textperthousand$, but several chemical factors remarkably fluctuated; dissolved oxygen 102.9~210.4%, COD 2.10~8.96mg$O_2$/l, pH 8.1~9.4, $NO_3$-N trace~1, 052$\mu$g/l, $PO_4$-P 0.6~58.9$\mu$g/l and chlorophyll-a 2.18~290.5mg/$m^3$ in the observed area. The red-tide was mainly caused by two dinoflagellata taxa throughout major outbreaks occurred in July through September. Leading species of red-tide were Gymnodinium nagasakiense belong to the ajor species. During the surveyed period, cell nubers of the causative organisms of the red-tide extensively varied from 3${\times} /10^4$ cells/l to $1.5\times10^7 $cells/l with moths and stations; Prorocentrum spp. 0.3~12.5$\times\10^5$ cells/l in July; Gymnodinium nagasakiense 0.2~5.9$\times10^6 cells/l, 1.1~4.7$\times10^6$ cells/l, and 0.2~15.1$\times10^6$ cells/l in July, August, and September, respectively. Gymnodinium nagasakiense red-tide seemed to be caused by the high water temperature in summer, unusually low salinity due to heavy rains, and the concentrated nutrients for phytoplankton supplied with the municipal sewages from the urban areas and the wastewaters from the industrial complexes.

  • PDF

Degradation of Raw Starch Granules by α-Amylase Purified from Culture of Aspergillus awamori KT-11

  • Matsubara, Takayoshi;Ammar, Youssef Ben;Anindyawati, Trisanti;Yamamoto, Satoru;Ito, Kazuo;Iizuka, Masaru;Minamiura, Noshi
    • BMB Reports
    • /
    • v.37 no.4
    • /
    • pp.422-428
    • /
    • 2004
  • Raw-starch-digesting $\alpha$-amylase (Amyl III) was purified to an electrophoretically pure state from the extract of a koji culture of Aspergillus awamori KT-11 using wheat bran in the medium. The purified Amyl III digested not only soluble starch but also raw corn starch. The major products from the raw starch using Amyl III were maltotriose and maltose, although a small amount of glucose was produced. Amyl III acted on all raw starch granules that it has been tested on. However, it was considered that the action mode of the Amyl III on starch granules was different from that of glucoamylase judging from the observation of granules under a scanning electron microscope before and after enzyme reaction, and also from the reaction products. Glucoamylase (GA I) was also isolated and it was purified to an electrophoretically pure state from the extract. It was found that the electron micrographic features of the granules after treatment with the enzymes were quite different. A synergistic effect of Amyl III and GA I was observed for the digestion of raw starch granules.

Cobalt Chloride-induced Apoptosis and Extracellular Signal-regulated Protein Kinase 1/2 Activation in Rat C6 Glioma Cells

  • Yang, Seung-Ju;Pyen, Jhin-Soo;Lee, In-Soo;Lee, Hye-Young;Kim, Young-Kwon;Kim, Tae-Ue
    • BMB Reports
    • /
    • v.37 no.4
    • /
    • pp.480-486
    • /
    • 2004
  • Brain ischemia brings about hypoxic insults. Hypoxia is one of the major pathological factors inducing neuronal injury and central nervous system infection. We studied the involvement of mitogen-activated protein (MAP) kinase in hypoxia-induced apoptosis using cobalt chloride in C6 glioma cells. In vitro cytotoxicity of cobalt chloride was tested by MTT assay. Its $IC_{50}$ value was $400\;{\mu}M$. The DNA fragment became evident after incubation of the cells with $300\;{\mu}M$ cobalt chloride for 24 h. We also evidenced nuclear cleavage with morphological changes of the cells undergoing apoptosis with electron microscopy. Next, we examined the signal pathway of cobalt chloride-induced apoptosis in C6 cells. The activation of extracellular signal-regulated protein kinase 1/2 (ERK 1/2) started to increase at 1 h and was activated further at 6 h after treatment of 400 M cobalt chloride. In addition, pretreatment of PD98059 inhibited cobalt chloride-induced apoptotic cell morphology in Electron Microscopy. These results suggest that cobalt chloride is able to induce the apoptotic activity in C6 glioma cells, and its apoptotic mechanism may be associated with signal transduction via MAP kinase (ERK 1/2).

Identification, Characterization and Phylogenic Analysis of Conserved Genes within the odvp-6e/odv-e56 Gene Region of Choristoneura fumiferana Granulovirus

  • Rashidan, Kianoush Khajeh;Nassoury, Nasha;Giannopoulos, Paresa N.;Mauffette, Yves;Guertin, Claude
    • BMB Reports
    • /
    • v.37 no.2
    • /
    • pp.206-212
    • /
    • 2004
  • The genes that are located within the odvp-6e/odv-e56 region of the Choristoneura fumiferana granulovirus (ChfuGV) were identified by sequencing the 11 kb BamHI restriction fragment on the ChfuGV genome. The global GC content that was calculated from the data obtained from this genomic region was 34.96%. The open-reading frames (ORFs), located within the odvp-6e/odv-e56 region, are presented and compared to the equivalent ORFs that are located at the same region in other GVs. This region is composed of 14 ORFs, including three ORFs that are unique to ChfuGV with no obvious homologues in other baculoviruses as well as eleven ORFs with homologues to granuloviral ORFs, such as granulin, CfORF2, pk-1, ie-1, odv-e18, p49, and odvp-6e/odv-e56. In this study, the conceptual products of seven major conserved ORFs (granulin, CfORF2, IE-1, ODV-E18, p49 and ODVP-6E/ODV-E56) were used in order to construct phylogenetic trees. Our results show that granuloviruses can be grouped in 2 distinct groups as follows: Group I; Choristoneura fumiferana granulovirus (ChfuGV), Cydia pomonella granulovirus (CpGV), Phthorimaea operculella granulovirus (PhopGV), and Adoxophyes orana granulovirus (AoGV). Group II; Xestia c-nigrum granulovirus (XcGV), Plutella xylostella granulovirus (PxGV), and Trichoplusia ni granulovirus (TnGV). The ChfuGV conserved proteins are most closely related to those of CpGV, PhopGV, and AoGV. Comparative studies, performed on gene arrangements within this region of genomes, demonstrated that three GVs from group I maintain similar gene arrangements.

Alternative Splicing of Breast Cancer Associated Gene BRCA1 from Breast Cancer Cell Line

  • Lixia, Miao;Zhijian, Cao;Chao, Shen;Chaojiang, Gu;Congyi, Zheng
    • BMB Reports
    • /
    • v.40 no.1
    • /
    • pp.15-21
    • /
    • 2007
  • Breast cancer is the most common malignancy among women, and mutations in the BRCA1 gene produce increased susceptibility to these malignancies in certain families. In this study, the forward 1-13 exons of breast cancer associated gene BRCA1 were cloned from breast cancer cell line ZR-75-30 by RT-PCR method. Sequence analysis showed that nine BRCA1 splice forms were isolated and characterized, compared with wild-type BRCA1 gene, five splice forms of which were novel. These splice isoforms were produced from the molecular mechanism of 5' and 3' alternative splicing. All these splice forms deleting exon 11b and the locations of alternative splicing were focused on two parts:one was exons 2 and 3, and the other was exons 9 and 10. These splice forms accorded with GT-AG rule. Most these BRCA1 splice variants still kept the original reading frame. Western blot analysis indicated that some BRCA1 splice variants were expressed in ZR-75-30 cell line at the protein level. In addition, we confirmed the presence of these new transcripts of BRCA1 gene in MDA-MB-435S, K562, Hela, HLA, HIC, H9, Jurkat and human fetus samples by RT-PCR analysis. These results suggested that breast cancer associated gene BRCA1 may have unexpectedly a large number of splice variants. We hypothesized that alternative splicing of BRCA1 possibly plays a major role in the tumorigenesis of breast and/or ovarian cancer. Thus, the identification of cancer-specific splice forms will provide a novel source for the discovery of diagnostic or prognostic biomarkers and tumor antigens suitable as targets for therapeutic intervention.