Streptomyces Coelicolor'daki metabolik değişiklikler üzerine bir araştırma

Tez (doktora) - Anadolu ÜniversitesiAnadolu Üniversitesi, Fen Bilimleri Enstitüsü, Biyoloji Anabilim DalıKayıt no: 450179Streptomisetler antibiyotikleri de içeren sekonder metabolitleri üretme yeteneğine sahip olmalarıyla bilinen başlıca toprak bakterileridir. Bu grubun üyeleri aynı zamanda sporulasyon olarak bilinen düzenli bölünme işlemi geçiren havasal hiflerin ereksiyonunu içeren çok kompleks morfolojik farklılıklar göstermektedirler. Streptomyces coelicolor Streptomiset genetik çalışmaları için model organizmadır ve genom dizisi belirlenmiştir. SCO2836 ve SCO2837'nin açık okuma çerçeveleri Streptomyces coelicolor A3(2) genomunun temel hücresel fonksiyonlar için gerekli genleri içeren korunmuş merkez çekirdek bölge içerisinde bulunmaktadır. SCO2836 ve SCO2837 genleri sırasıyla glikozil transferaz ve galaktoz oksidaz domaini içerdigi sanılan proteinleri kodlar. Bu çalışmada SCO2836 ve SCO2837 genleri in vitro olarak Tn5062 transpozonu ile mutasyona uğratıldı ve bu mutasyonların fenotipik etkileri farklı ortamlarda araştırıldı. Her iki mutantta da ortam koşullarına bağlı olarak havasal gelişmede gecikme gösterdi. Bu mutasyonlar Southern Blot ile doğrulandı. Ayrıca bu iki genin promotor bölgesinin oldugu kısım pRLux87 plazmitine aktarılarak farklı besiyerlerinde lusiferaz aktivitesine de bakıldı

ASSESSMENT OF CYTOTOXICITY OF A CAFFEINATED SOFT DRINK USING ALLIUM ASSAY

One of the most consumed caffeinated soft drinks by millions of people globally is Coca-Cola. For healthy adults, caffeine consumption is relatively safe, but for some vulnerable populations, caffeine consumption could be harmful. Therefore, we considered this cytogenetic study to be appropriate for assessment of cytotoxicity effects of Coca-Cola in meristematic cells of plants, through Allium test. A. cepa has assayed to be one of the best model plants for standard use in cytological analysis of different toxins for their cytotoxicity and genotoxicity to plants and animals. The meristematic roots were treated with various concentrations of Coca-Cola (3, 5 and 10ml/cl) for 8 hours, at room temperature, along to an untreated control. It was found that Coca-Cola induced a strong cytogenotoxic effect in meristematic cells of A. cepa as the concentration of Coca-Cola was increased. The clastogenic and aneugenic effect of the tested product was manifested by the decrease of mitotic index (12.5-3.5%) and the occurrence of several types of chromosomal and nuclear abnormalities (12.6-23.2%): bridges, laggards, stickiness and disrupted nucleus. These results suggest that the caffeinated soft drinks can be harmful to health and their regular intake must be avoided. The problem can arises when the consumption is regularized in everyday life, as, unfortunately, many people do

THE INFLUENCE OF ORANGE JUICE ON MITOSIS AND IN VITRO GROWTH TO HIBISCUS ESCULENTUS

The regeneration capacity of the cells of an explant depends on several factors: the nature and origin of the explants, their type, structure and degree of juvenility, cell maturity and physiological state, endogenous phytohormone content, composition of culture medium and culture conditions, etc. Among them, the culture medium is an essential factor for the success of in vitro culture. In its composition, in addition to macro and microelements, vitamins, sucrose, etc., can be added some natural nutritional extracts, such as deproteinated coconut milk or various vegetable and fruit juices, to improve the complexity of the culture medium. This paper presents the results obtained in the laboratory from the in vitro culture of okra (Hibiscus esculentus), on modified Murashige-Skoog culture medium (MS) by adding natural orange juice in three different concentrations: 5, 10 and 20%. It was observed that at the 10% concentration of orange juice were registered the highest values, both in terms of germination, explant growth and mitotic activity. The lowest values from this point of view were obtained at a concentration of 20%. These results suggest the nutritional potential of orange juice added to the MS culture medium to increase the growth rate and in vitro survival of okra via cells competence improvement

GENETIC BIOENGINEERING IN AGRICULTURE - A MODEL SYSTEM FOR STUDY OF THE MECHANISM OF PROGRAMMED CELL DEATH

The behaviour of in vitro cell cultures is different from that of in vivo cells, when they are integrated into the organism. The selective death of cells, tissues and organs is a feature of plant development and survival. The process is called programmed cell death due to the organism's involvement in controlling of the initiation and execution of this process. The programmed cell death is an active, genetically controlled process that leads to the selective elimination of damaged cells. This complex process is present throughout the life of plants, from the seed germination to the maturation and senescence of plants. Cell death in plants has specific features due to the cell wall in particular but also of the presence of some specific structures of the plant cell, such as chloroplasts and vacuole. Exposure of plants to various stressors can induce oxidative stress and can be followed by cell death. However, cell death under abiotic stress conditions can also be a regulated process, meant to ensure the survival of plants. The programmed cell elimination plays an essential role in the desired modelling of plants, and this goal is the prerogative of genetic bioengineering, via cell cultures. The fascinating field of genetic bioengineering has a huge potential for the programmed modelling of the plants and obtaining new genotypes, with superior properties and high capacity to adapt to different environmental conditions, corresponding to the requirements of a sustainable management of modern agriculture

Evaluation of genotoxic and mutagenic effects of aqueous extract from aerial parts of Linaria genistifolia subsp. genistifolia

Genotoxic and mutagenic effects of aqueous extract from aerial parts Linaria genistifolia (L.) Mill. subsp. genistifolia, Plantaginaceae (Lg-ext) were investigated by using both Allium cepa root meristematic cells and bacterial reverse mutation assay in Salmonella typhimurium TA98 and TA100 with or without metabolic activation system (S9), respectively. In Allium root growth inhibition test, EC50 value was determined approximately 15 g/L and 0.5xEC50, EC50 and 2xEC50 concentrations of Lg-ext were introduced to onion tuber roots and distilled water and methyl methane sulfonate (MMS, 10 ppm) used as a negative and positive control, respectively. The characteristic effect caused by tested preparations was an increase of mitotic index (MI) in 7.5 g/L and 15 g/L (except 24 and 96 h) and simultaneous decrease of MI in 30 g/L and in MMS. While stickiness, bridges, chromosome laggards and disturbed anaphase-telophase were observed in anaphase-telophase cells, c-metaphase, pro-metaphase, polyploidy and binuclear cells were observed in other cells. Lg-ext was not found to be mutagenic on S. typhimurium TA 98 and TA100 with or without S9. The results were also analyzed statistically by using SPSS for Windows, and Duncan's multiple range tests were performed respectively. These results indicate that Lg-ext exhibits genotoxic activity in A. cepa root meristematic cells but not mutagenic activity in Ames test syste

In silico analysis of DEL-1 and inflammation-related genes in lung squamous cell carcinoma

Aim: Twenty to thirty percent of non-small cell lung cancers (NSCLC) are caused by lung squamous cell carcinoma (LUSC), especially in smokers and there has been limited study previously evaluating the situation in terms of the genome and gene expression profile, which demonstrates the relationship among DEL-1, leucocyte recruitment, and pro-inflammatory cytokines in LUSC. Material and methods: In the current study, the m-RNA expression patterns and mutation profiles of our target genes, such as, pro-inflammatory cytokines, chemoattractant molecules, and DEL-1 genes, in 511 LUSC patients. To find the harmful mutations, the PolyPhen-2 and SNAP programs were employed. Not only gene expression was detected, but also survival analysis and correlation between DEL-1 and other target genes' expression levels were explored too. Results: Target genes such as, DEL-1, TNF, IL-18, IL-1, CXCL8, CXCL13, and IL-6 were found to have a total genetic anomaly carrying rate of 16.4%. Seven mutations were found, and two of those mutations have a pathogenic aspect. Deep deletion and gene amplification of the genetic anomalies were also observed. According to gene expression analysis results in the LUSC patient group; DEL-1 and IL-6 levels were significantly lower than those of the control group, whereas the CXCL13 level was found to be higher. Conclusion: Findings of the current study revealed that, there is a significant role of DEL-1 in LUSC pathogenesis. Since present study is an in silico-centered study, this approach can give more insight on experimental studies. These events may support that one of the cancer improvement mechanisms depending on DEL-1 gene at the molecular level.The data used in present study are obtained from public database the TCGA Research Network: https:// www.cancer.gov/tcga. We thank the TCGA and GEPIA databases for the availability of the data

Mutagenicity and genotoxicity of dicapthon insecticide

Mutagenic and genotoxic effects of dicapthon were investigated by using the bacterial reverse mutation assay in Salmonella typhimurium TA97, TA98, TA100 and TA102 strains with or without metabolic activation system (S9 mix), and chromosome aberrations (CAs), sister chromatid exchanges (SCEs), and micronucleus (MN) tests in human peripheral blood lymphocytes in vitro. Dicapthon was dissolved in dimethyl sulfoxide for all test systems. 0.1, 1, 10 and 100 ?g/plate doses of dicapthon were found to be weakly mutagenic on S. typhimurium TA 98 without S9 mix. The human peripheral lymphocytes were treated with four experimental concentrations of dicapthon (25, 50, 100, and 200 ?g/mL) for 24 and 48 h. Dicapthon increased the frequency of SCE only at the 100 ?g/mL concentration for the 24 and 48 h applications. Dicapthon also induced abnormal cell frequency, CA/cell ratio and frequency of MN dose dependently for 24 and 48 h. Dicapthon showed a statistically significant cytotoxic effect by decreasing the mitotic index in all concentrations and a cytostatic effect by decreasing nuclear division index in 100 and 200 ?g/mL concentrations for both treatment periods when compared with both untreated and solvent controls. These values decreased also in a dose dependent manner. © 2014, Springer Science+Business Media Dordrecht

Genotoxic effects of bismuth (III) oxide nanoparticles by allium and comet assay

PubMed ID: 23790828Genotoxic effects of Bismuth (III) oxide nanoparticles (BONPs) were investigated on the root cells of Allium cepa by Allium and Comet assay. A. cepa roots were treated with the aqueous dispersions of BONPs at five different concentrations (12.5, 25, 50, 75, and 100. ppm) for 4. h. Exposure of BONPs significantly increased mitotic index (MI) except 12.5. ppm, total chromosomal aberrations (CAs) in Allium test. While stickiness chromosome laggards, disturbed anaphase-telophase and anaphase bridges were observed in anaphase-telophase cells, pro-metaphase and c-metaphase in other cells. A significant increase in DNA damage was also observed at all concentrations of BONPs except 12.5. ppm by Comet assay. The results were also analyzed statistically by using SPSS for Windows; Duncan's multiple range test was performed. These results indicate that BONPs exhibit genotoxic activity in A. cepa root meristematic cells. © 2013 Elsevier Ltd

Cytotoxic and Genotoxic Effects of Primite 20 WP Containing 20% Pyridaben on Allium cepa Root Meristematic Cells

%20 Pyridaben içeren Primite 20 WP (PİP) akarisit ve insektisit olarak kullanılmaktadır. Bu çalışmadaPİP’in sitotoksik ve genotoksik etkileri Allium cepa kök meristematik hücrelerinde kök büyümesi, mitotikindeks (Mİ), kromozomal anormallik (KA)’ler ve DNA hasarı üzerindeki etkileri Allium ana-telofaz veKomet testleri kullanılarak araştırılmıştır. Allium kök büyüme engelleme testi ile PİP’in kök uçlarınınbüyümesini negatif kontrol grubuna göre %50 oranında düşüren konsantrasyon (EC50) değeri, 50 ppmolarak bulunmuştur. A. cepa kökleri PİP’in üç farklı konsantrasyonu (25, 50 ve 100 ppm), distile su(negatif kontrol) ve metil metan sülfonata (MMS, 10 ppm, pozitif kontrol) 24, 48, 72 ve 96 saat maruzbırakılmıştır. PİP; kök büyümesini ve Mİ’yi istatistiksel olarak azaltarak sitotoksik etki, KA’ları (bozulmuşana-telofaz, kalgın kromozom, yapışıklık, köprü ve poliploidi) ve DNA hasarını istatistitiksel olarakartırarak genotoksik etki göstermiştir. PİP kullanımına dikkat edilmeli ve sito-genotoksik etkileri diğertoksisite test sistemleri ile araştırılmalıdır.Primite 20 WP containing 20% pyridaben (PCP) is used as an acaricide and insecticide. In this study,cytotoxic and genotoxic effects of PCP were investigated on the root meristem cells of Allium cepa forits effects on root growth, mitotic index (MI), mitotic phases, chromosomal abnormalities (CAs) andDNA damage by using Allium ana-telophase and Comet assays. The amount of PCP concentration thatreduces the growth of root tips by 50% compared to the negative control group (EC50)value wasdetermined as 50 ppm by Allium root growth inhibition test. A. cepa roots were treated with threeconcentrations of PCP (25, 50 and 100 ppm), distilled water (negative control) and methyl methanesulphonate (MMS, 10 ppm, positive control) for 24, 48, 72 and 96 h. PCPshowed a cytotoxic effect byreducing root growth and MI, but also showed genotoxic effect by increasing CAs (disturbed anatelophase,chromosome laggards, stickiness, bridges and polyploidy) and DNA damage at significantlevels. PCPshould be used carefully and investigated its cyto-genotoxic effects with other toxicology testsystems