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51.
Changku Kang Jong‐Yeol Moon Sang‐Im Lee Piotr G. Jablonski 《Biological journal of the Linnean Society. Linnean Society of London》2014,111(4):900-904
Camouflage conceals animals from predators and depends on the interplay between the morphology and behaviour of animals. Behavioural elements of animals, such as the choice of a resting spot or posture, are important for effective camouflage, as well as the animals’ cryptic appearance. To date, the type of sensory input that mediates resting site choice remains poorly understood. Previously, we showed that bark‐like moths perceive and rely on bark structure to seek out cryptic resting positions and body orientations on tree trunks. In the present study, we investigated the sensory organs through which moths perceive the structure of bark when positioning their bodies in adaptive resting orientations. We amputated (or blocked) each one of the hypothetical sensory organs in moths (antennae, forelegs, wings, and eyes) and tested whether they were still able to perceive bark structure properly and adopt adaptive resting orientations. We found that visual information or stimulation is crucial for adaptively orienting their bodies when resting and tactile information from wings may play an additional role. The present study reveals multimodal information use by moths to achieve visual camouflage and highlights the sensory mechanism that is responsible for the adaptive behaviour of cryptic insects. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111 , 900–904. 相似文献
52.
Min Seok Cho Sang Yeol Kim Ki Tae Suk Byung-Yong Kim 《Journal of microbiology (Seoul, Korea)》2018,56(12):855-867
Nonalcoholic fatty liver disease (NAFLD) is one of the most common types of liver diseases worldwide and its incidence continues to increase. NAFLD occurs when the body can no longer effectively store excess energy in the adipose tissue. Despite the increasing prevalence of NAFLD, making lifestyle changes, including increased exercise, is often an elusive goal for patients with NAFLD. The liver directly connects to the gut-gastrointestinal milieu via the portal vein, which are all part of the gut-liver axis. Therefore, the gut-microbiome and microbial products have been actively studied as likely key factors in NAFLD pathophysiology. Hence, dysbiosis of the gut microbiome and therapeutic manipulation of the gut-liver axis are being investigated. Novel therapeutic approaches for modulating gut microbiota through the administration of probiotics, prebiotics, synbiotics, and antibiotics have been proposed with numerous promising initial reports on the effectiveness and clinical applications of these approaches. This review delves into the current evidence on novel therapies that modulate gut microbiota and discusses ongoing clinical trials targeting the gut-liver axis for the management and prevention of NAFLD. 相似文献
53.
Gyoo Yeol Jung Jung Rae Kim Hyun Ok Jung Ji-Young Park Sunghoon Park 《Biotechnology letters》1999,21(10):869-873
A new bacterium, Citrobacter sp. Y19, catalyzing the water-gas shift reaction was isolated from an anaerobic wastewater sludge digester. It grew aerobically with a high specific growth rate of 0.7 h–1 in a mineral salt medium supplemented with yeast extract and Bacto-tryptone, and produced H2 under anaerobic conditions after the cells were transferred to tryptone-deleted medium. The maximum H2 production rate was 33 mmol H2 g–1 cell h, which was maintained for about 200 h. This is the first report on a chemoheterotrophic bacterium which utilizes CO with the production of H2 and CO2. 相似文献
54.
Sang Hyeon Kang Sang Taek Jung Taek Jin Kang Ryang Guk Kim Sang Hyuk Suh Ji Hyoung Woo Eun Yeol Lee Cha Yong Choi 《Biotechnology Techniques》1999,13(11):761-764
Each of the four nucleotides (A, C, G and T) was introduced as the base following the stop codon to investigate the effect of this fourth base on translational termination efficiency during the heterologous expression of human erythropoietin (hEPO) in E. coli. The efficiency of peptide chain termination in E. coli was markedly dependent on the fourth base. The choice of the fourth base was crucial to prevent the expression of undesirable proteins due to the translational infidelity such as frameshifting and stop codon read-through, and translational termination efficiency could be improved with adenosine as the fourth base. 相似文献
55.
Seungha Hwang Cha Yong Choi Eun Yeol Lee 《Biotechnology and Bioprocess Engineering》2008,13(4):453-457
An enantioconvergent biotransformation of racemic styrene oxide by using two recombinant microbial epoxide hydrolases (EHs)
in one pot has been investigated to prepare enantiopure vicinal diols. The recombinant whole cell possessing EH gene from
Aspergillus niger LK or Rhodotorula glutinis exhibited a complementary enantioselectivity and regioselectivity, compared to the recombinant cell containing Caulobacter crescentus EH gene. When two recombinant microbial EHs were used in combination, 1.3 g of enantiopure (R)-1,2-phenylethandiol with more than 90% enantiopurity and 95% overall yield was obtained from 1.2 g of racemic styrene oxide
in a preparative-scale batch enantioconvergent biotransformation. 相似文献
56.
Park H Hwang KY Kim YH Oh KH Lee JY Kim K 《Bioorganic & medicinal chemistry letters》2008,18(13):3711-3715
Discovery of alpha-glucosidase inhibitors has been actively pursued with the aim to develop therapeutics for the treatment of diabetes and the other carbohydrate-mediated diseases. We have identified four novel alpha-glucosidase inhibitors by means of a drug design protocol involving the structure-based virtual screening under consideration of the effects of ligand solvation in the scoring function and in vitro enzyme assay. Because the newly identified inhibitors reveal in vivo antidiabetic activity as well as a significant potency with more than 70% inhibition of the catalytic activity of alpha-glucosidase at 50 microM, all of them seem to deserve further development to discover new drugs for diabetes. Structural features relevant to the interactions of the newly identified inhibitors with the active site residues of alpha-glucosidase are discussed in detail. 相似文献
57.
Translational efficiency in Escherichia coli is known to be strongly influenced by the secondary structure around the ribosome‐binding site and the initiation codon in the translational‐initiation region of the mRNA. Several quantitative studies have reported that translational efficiency is attributable to effects on ribosome accessibility predominantly caused by the secondary structure surrounding the ribosome‐binding site. However, the influence of mRNA secondary structure around regions downstream of the initiation codon on translational efficiency after ribosome‐binding step has not been quantitatively studied. Here, we quantitatively analyzed the relationship between secondary structure of mRNA surrounding the region downstream of the initiation codon, referred to as the downstream region (DR), and protein expression levels. Modified hairpin structures containing the initiation codon were constructed by site‐directed mutagenesis, and their effects on expression were analyzed in vivo. The minimal folding free energy (ΔG) of a local hairpin structure was found to be linearly correlated with the relative expression level over a range of fourfold change. These results demonstrate that expression level can be quantitatively controlled by changing the stability of the secondary structure surrounding the DR. Biotechnol. Bioeng. 2009; 104: 611–616 © 2009 Wiley Periodicals, Inc. 相似文献
58.
Effects of human amniotic membrane grafts combined with marrow mesenchymal stem cells on healing of full-thickness skin defects in rabbits 总被引:1,自引:0,他引:1
Sung Soo Kim Chang Keun Song Sung Keun Shon Kyu Yeol Lee Chul Hong Kim Myung Jin Lee Lih Wang 《Cell and tissue research》2009,336(1):59-66
We have investigated the wound-healing effects of mesenchymal stem cells (MSCs) in combination with human amniotic membrane
(HAM) when grafted into full-thickness skin defects of rabbits. Five defects in each of four groups were respectively treated
with HAM loaded with autologous MSCs (group A), HAM loaded with allologous MSCs (group B), HAM with injected autologous MSCs
(group C), and HAM with injected allologous MSCs (group D). The size of the wounds was calculated for each group at 7, 12,
and 15 days after grafting. The wounds were subsequently harvested at 25 days after grafting. Sections stained with hematoxylin
and eosin were used to determine the quality of wound healing, as based on the characteristics and amount of granulated tissue
in the epidermal and dermal layers. Groups A and B showed the most pronounced effect on wound closure, with statistically
significant improvement in wound healing being seen on post-operative days 7, 12, and 15. Although a slight trend toward improved
wound healing was seen in group A compared with group B, no statistically significant difference was found at any time point
between the two groups. Histological examination of healed wounds from groups A and B showed a thin epidermis with mature
differentiation and collagen bundle deposition plus recovered skin appendages in the dermal layer. In contrast, groups C and
D showed thickened epidermis with immature epithelial cells and increased fibroblast proliferation with only partially recovered
skin appendages in the dermal layer. Thus, the graft of HAM loaded with MSCs played an effective role during the healing of
skin defects in rabbits, with no significant difference being observed in wound healing between autologous and allologous
MSC transplantation.
This study was supported by research funds from Dong-A University. 相似文献
59.
Jung Eun Hwang Joon Ki Hong Ji Hyun Je Kyun Oh Lee Dool Yi Kim Sang Yeol Lee Chae Oh Lim 《Plant cell reports》2009,28(11):1623-1632
Phytocystatins are cysteine proteinase inhibitors in plants that are implicated in the endogenous regulation of protein turnover
and defense mechanisms against insects and pathogens. A cDNA encoding a phytocystatin called AtCYS6 (Arabidopsis thaliana phytocystatin6) has been isolated. We show that AtCYS6 is highly expressed in dry seeds and seedlings and that it also accumulates
in flowers. The persistence of AtCYS6 protein expression in seedlings was promoted by abscisic acid (ABA), a seed germination
and post-germination inhibitory phytohormone. This finding was made in transgenic plants bearing an AtCYS6 promoter–β-glucuronidase (GUS) reporter construct, where we found that expression from the AtCYS6 promoter persisted after ABA treatment but was reduced under control conditions and by gibberellin4+7 (GA4+7) treatment during the germination and post-germinative periods. In addition, constitutive over-expression of AtCYS6 retarded germination and seedling growth, whereas these were enhanced in an AtCYS6 knock-out mutant (cys6-2). Additionally, cysteine proteinase activities stored in seeds were inhibited by AtCYS6 in transgenic Arabidopsis. From these data, we propose that AtCYS6 expression is enhanced by the germination inhibitory phytohormone ABA and that it participates in the control of germination
rate and seedling growth by inhibiting the activity of stored cysteine proteinases. 相似文献
60.
Kim MG Geng X Lee SY Mackey D 《The Plant journal : for cell and molecular biology》2009,57(4):645-653
Plant disease resistance (R) proteins recognize potential pathogens expressing corresponding avirulence (Avr) proteins through 'gene-for-gene' interactions. RPM1 is an Arabidopsis R-protein that triggers a robust defense response upon recognizing the Pseudomonas syringae effector AvrRpm1. Avr-proteins of phytopathogenic bacteria include type III effector proteins that are often capable of enhancing virulence when not recognized by an R-protein. In rpm1 plants, AvrRpm1 suppresses basal defenses induced by microbe-associated molecular patterns. Here, we show that expression of AvrRpm1 in rpm1 plants induced PR-1, a classical defense marker, and symptoms including chlorosis and necrosis. PR-1 expression and symptoms were reduced in plants with mutations in defense signaling genes ( pad4 , sid2 , npr1 , rar1 , and ndr1 ) and were strongly reduced in rpm1 rps2 plants, indicating that AvrRpm1 elicits defense signaling through the Arabidopsis R-protein, RPS2. Bacteria expressing AvrRpm1 grew more on rpm1 rps2 than on rpm1 plants. Thus, independent of its classical 'gene-for-gene' activation of RPM1, AvrRpm1 also induces functionally relevant defenses that are dependent on RPS2. Finally, AvrRpm1 suppressed host defenses and promoted the growth of type III secretion mutant bacteria equally well in rps2 and RPS2 plants, indicating that virulence activity of over-expressed AvrRpm1 predominates over defenses induced by weak activation of RPS2. 相似文献