• Title/Summary/Keyword: Lethality

Search Result 260, Processing Time 0.024 seconds

Misexpression of AtTX12 encoding a Toll/interleukin-1 receptor domain induces growth defects and expression of defense-related genes partially independently of EDS1 in Arabidopsis

  • Song, Sang-Kee
    • BMB Reports
    • /
    • v.49 no.12
    • /
    • pp.693-698
    • /
    • 2016
  • In this study, a tissue-specific GAL4/UAS activation tagging system was used for the characterization of genes which could induce lethality when ubiquitously expressed. A dominant mutant exhibiting stunted growth was isolated and named defective root development 1-D (drd1-D). The T-DNA tag was located within the promoter region of AtTX12, which is predicted to encode a truncated nucleotide-binding leucine-rich repeat (NLR) protein, containing a Toll/interleukin-1 receptor (TIR) domain. The transcript levels of AtTX12 and defense-related genes were elevated in drd1-D, and the misexpression of AtTX12 recapitulated the drd1-D phenotypes. In the presence of ENHANCED DISEASE SUSCEPTIBILITY 1 (EDS1), a key transducer of signals triggered by TIR-type NLRs, a low-level of AtTX12 misexpression induced strong defective phenotypes including seedling lethality whereas, in the absence of EDS1, a high-level of AtTX12 misexpression induced weak growth defects like dwarfism, suggesting that AtTX12 might function mainly in an EDS1-dependent and partially in an EDS1-independent manner.

The roles of FADD in extrinsic apoptosis and necroptosis

  • Lee, Eun-Woo;Seo, Jin-Ho;Jeong, Man-Hyung;Lee, Sang-Sik;Song, Jae-Whan
    • BMB Reports
    • /
    • v.45 no.9
    • /
    • pp.496-508
    • /
    • 2012
  • Fas-associated protein with death domain (FADD), an adaptor that bridges death receptor signaling to the caspase cascade, is indispensible for the induction of extrinsic apoptotic cell death. Interest in the non-apoptotic function of FADD has greatly increased due to evidence that FADD-deficient mice or dominant-negative FADD transgenic mice result in embryonic lethality and an immune defect without showing apoptotic features. Numerous studies have suggested that FADD regulates cell cycle progression, proliferation, and autophagy, affecting these phenomena. Recently, programmed necrosis, also called necroptosis, was shown to be a key mechanism that induces embryonic lethality and an immune defect. Supporting these findings, FADD was shown to be involved in various necroptosis models. In this review, we summarize the mechanism of extrinsic apoptosis and necroptosis, and discuss the in vivo and in vitro roles of FADD in necroptosis induced by various stimuli.

A Study on the Accuracy Analysis for Air-to-Ground Weapon Delivery (공대지 무장투하정확도 해석에 대한 연구)

  • Jo, Han-Sang;Song, Chae-Il;Lee, Sang-Chul
    • Journal of the Korean Society for Aeronautical & Space Sciences
    • /
    • v.35 no.8
    • /
    • pp.741-746
    • /
    • 2007
  • In this paper, we propose an accuracy analysis method for air-to-ground weapon delivery. The lethality, which is one of the most important factor to evaluate combat effectiveness of a fighter, depends on the capability to improve the accuracy of the conventional weapon delivery. We present error elements which affect the error analysis for air-to-ground weapon delivery from the initial design phase to the final validation phase. And we introduce an accuracy analysis method to reflect the error elements and to evaluate them quantitatively. We assume zero bias-error and consider random error for the weapon delivery accuracy analysis.

Pharmacological profiles of Holarhena antidysenterica (L.) Wall bark

  • Rahman, Shafiur;Ali, Eunus;Haque, Rubyat
    • Advances in Traditional Medicine
    • /
    • v.7 no.2
    • /
    • pp.157-161
    • /
    • 2007
  • We undertook the present study to evaluate different pharmacological as antioxidant, antibacterial and cytotoxic activities of the crude ethanolic extract of the stem bark of Holarhena antidysenterica (Family: Apocynaceae). The antioxidant property of the extract was assessed by 1,1-diphenyl-2-picryl hydrazyl free radical scavenging assay. The extract showed antioxidant activity ($IC_{50}$ about ${\sim}08$ ${\mu}g/ml$), which was comparable to standard drug ascorbic acid ($IC_{50}$ about ${\sim}10$ ${\mu}g/ml$). The extract showed a broad spectrum of antibacterial activity against all tested gram positive and gram negative bacteria most prominent against Enterococci, Staphylococcus pyogenase and Shigella sonnie. And the zones of inhibitions were ranging from 10 - 21 mm for all the tested bacteria. Its cytotoxic property was evaluated by brine shrimp lethality bioassay. The extract showed significant lethality and the $LC_{50}$, $LC_{90}$ values were 80 ${\mu}g/ml$, 320 ${\mu}g/ml$ respectively. The results tend to suggest that the extract might possess chemical constituent(s) that are responsible for antioxidant, antibacterial and cytotoxic activities.

Brca2 Deficiency Leads to T Cell Loss and Immune Dysfunction

  • Jeong, Jun-Hyeon;Jo, Areum;Park, Pilgu;Lee, Hyunsook;Lee, Hae-Ock
    • Molecules and Cells
    • /
    • v.38 no.3
    • /
    • pp.251-258
    • /
    • 2015
  • Germline mutations in the breast cancer type 2 susceptibility gene (BRCA2) are linked to familial breast cancer and the progressive bone marrow failure syndrome Fanconi anaemia. Established Brca2 mouse knockout models show embryonic lethality, but those with a truncating mutation at the C-terminus survive to birth and develop thymic lymphoma at an early age. To overcome early lethality and investigate the function of BRCA2, we used T cell-specific conditional Brca2 knockout mice, which were previously shown to develop thymic lymphoma at a low penetrance. In the current study we showed that the number of peripheral T cells, particularly na$\ddot{i}$ve pools, drastically declined with age. This decline was primarily ascribed to improper peripheral maintenance. Furthermore, heterozygous mice with one wild-type Brca2 allele manifested reduced T cell numbers, suggesting that Brca2 haploinsufficiency might also result in T cell loss. Our study reveals molecular events occurring in Brca2-deficient T cells and suggests that both heterozygous and homozygous Brca2 mutation may lead to dysfunction in T cell populations.

Cochlodinium Red Tide Effects on the Respiration of Abalone, Haliotis discus hannai Ino

  • Seo, Kyung-Suk;Lee, Chang-Kyu
    • ALGAE
    • /
    • v.22 no.3
    • /
    • pp.241-246
    • /
    • 2007
  • Cochtodinium votykrikoides -related red tide is the most notorious tidal bloom, resulting in mass mortality to marineanimals. This study aimed to test the effect of C. polyknkoides on the lethality to Haliotis discus hannai under con-trolled conditions. The oxygen demand of C. polykrikoides increases to reach its peak duhng the night, while the oxy-gen usage by H. discus hannai was continuously decreased with a threshold of 2 mg L U. The addition of C.polykrikoides did not effect the respiration of the H. discus hannai. However, the usage of oxygen by C. polykrikoidesduhng the night may lead to anoxia in the animal. With aeration, the level of dissolved oxygen (D.O.) was between6.06 and 7.28 mg LU; 90% of abalones survived even with a high concentration of C. potykrikoides (9000 cells mL U).Without aeration (3 mg LU of D.O.), however, the H. discus hannai suffocated immediately. Once 20 hours hadelapsed, all of the abalones were dead. The density of the H. discus hannai population contributed to their mortality.Therefore, aeration during the night and maintaining lower abalone densities is the best way to promote the sur-vivorship of H. discus hannai during a C. polykrikoides red tide.

Adaptive Responses on Survival and Mutagenesis during MNNG Pretreatmeat and Lethality to UV MNNG at Different Cell Stages in Aspergillus nidulans (Aspergillus nidulans에서 MNNG 선 처리시의 생존도와 돌연변이 유발에 대한 Adaptive response 및 Cell stage 따른 UV와 MNNG에 대한 치사율 조사)

  • Chae, Suhn-Kee
    • The Journal of Natural Sciences
    • /
    • v.9 no.1
    • /
    • pp.45-52
    • /
    • 1997
  • We have examined the effects of low concentrations of MNNG, alkylating agent, in survival and mutagenesis in Aspergillus nidulans. Pretreatments of cells with nontoxic and submutagenic doses of MNNG did not reduce the cytotoxic and mutagenic effects of exposure to a high concentration of drug. The results imply that adaptive responses on survival and mutagenesis for MNNG treatments do not occur in Aspergillus nidulans. In the first mitotic cell cycle during germination, the sensitivity to MNNG has been investigated at hourly time interval, and compared with that for UV irradiation. In both UV and MNNG treatments, the sensitivity increased till S cell stage, and decreased while DNA replication continued. Different from that show for UV irradiation, lethality to MNNG reached to the maximum at G2 cell stage.

  • PDF

Antimicrobial activity and toxicity of Quisqualis indica

  • Jahan, Fatima N.;Rahman, Mohammad S.;Hossain, Mahboob;Rashid, Mohammad A.
    • Advances in Traditional Medicine
    • /
    • v.8 no.1
    • /
    • pp.53-58
    • /
    • 2008
  • The plant Quisqualis indica (Compositae) has ehnopharmcological reputation of being used as a healing agent in Bangladesh. In this study, preliminary screenings were conducted to look at the antimicrobial susceptibility and cytotoxicity of the plant extract. The extractives of the plant were subjected to screening for inhibition of microbial growth by the disc diffusion method. The zones of inhibition demonstrated by the n-hexane, carbon tetrachloride, chloroform and aqueous soluble partitionates of the methanolic extract ranged from 8 - 15 mm, 8 - 18 mm, 12 - 20 mm and 10 - 16 mm, respectively at a concentration of 400 ${\mu}g$/disc. All the extractives were also subjected to brine shrimp lethality bioassay for primary cytotoxicity evaluation. Here, the carbon tetrachloride soluble materials demonstrated the highest cytotoxicity with $LC_{50}$ of 0.826 ${\mu}g$/ml, while n-hexane, chloroform and aqueous soluble partitionates of the methanolic extract revealed the $LC_{50}$ of 1.254, 3.866 and 5.366 ${\mu}g$/ml, respectively. This is the first report of the antimicrobial activity and cytotoxicity Q. indica.

Deficiency of Bloom's Syndrome Protein Causes Hypersensitivity of C. elegans to Ionizing Radiation but Not to UV Radiation, and Induces p53-dependent Physiological Apoptosis

  • Kim, Yun Mi;Yang, Insil;Lee, Jiyeung;Koo, Hyeon-Sook
    • Molecules and Cells
    • /
    • v.20 no.2
    • /
    • pp.228-234
    • /
    • 2005
  • Caenorhabditis elegans him-6 mutants, which show a high incidence of males and partial embryonic lethality, are defective in the orthologue of human Bloom's syndrome protein (BLM). When strain him-6(e1104) containing a missense him-6 mutation was irradiated with ${\gamma}$-rays during germ cell development or embryogenesis, embryonic lethality was higher than in the wild type, suggesting a critical function of the wild type gene in mitotic and pachytene stage germ cells as well as in early embryos. Even in the absence of ${\gamma}$-irradiation, apoptosis was elevated in the germ cells of the him-6 strain and this increase was dependent on a functional p53 homologue (CEP-1), suggesting that spontaneous DNA damage accumulates due to him-6 deficiency. However, induction of germline apoptosis by ionizing radiation was not significantly affected by the deficiency, indicating that HIM-6 has no role in the induction of apoptosis by exogenous DNA damage. We conclude that the C. elegans BLM orthologue is involved in DNA repair in promeiotic cells undergoing homologous recombination, as well as in actively dividing germline and somatic cells.

Studies on the Development of the Bacillus thuringiensis - Lethality and safety tests of the endotoxin and the pesticide of B. thuringiensis serovar kurstaki - (Bacillus thuringiensis 살충제 개발에 관한 연구 - B. thuringiensis serovar kurstaki 살충제와 내독소의 치사성과 안전성 연구 -)

  • 이형환
    • Microbiology and Biotechnology Letters
    • /
    • v.14 no.4
    • /
    • pp.325-328
    • /
    • 1986
  • The lethality to Pieris raepi larvae and the safety tests to mice of the endotoxin crystals and the pesticide of B thuringiensis serovar kurstaki were carried out. The LD50 of the endotoxin (3.9$\times$10$^9$ spores/$m{\ell}$) appeared to be 1$\mu$g and that of the pesticide (2.6$\times$10$^9$ spores/$m{\ell}$) was about 9 $\mu$g. When the endotoxin solution and the pesticide were injected to the mice's intraperitoneal cavities, 10 to 20% of the mite were dead. Also in the case of intracerebral injection 20% of the mice were dead at the doses of 7.8$\times$10$^3$ spores and 100% of the mice were dead at the concentration of 7.8$\times$10$^8$ spores. but the mice in the oral, subcutaneous and inhalation treatment groups were safe and healthy. When the pesticide applied to the cabbage field for raepi larvae, 52 to 65% of the larvae in the field were killed in 4 days postapplication.

  • PDF