Life Sciences Commons^™

The Mtt Viability Assay Yields Strikingly False-Positive Viabilities Although The Cells Are Killed By Some Plant Extracts, Di̇dem Karakaş, Ferda Ari, Engi̇n Ulukaya

Turkish Journal of Biology

The MTT assay is one of the often used cell viability/cytotoxicity assays. However, when the methanol extracts of plants are used to test their cytotoxic potential, interference may occur, resulting in false-positive viability results. Therefore, in this study, the reliability of the MTT assay was investigated in the case of plant use. The methanol extracts of three different plants (Hypericum adenotrichum, Salvia kronenburgii, and Pelargonium quercetorum) were tested in breast cancer cell lines (MCF-7 and MDA-MB-231) using the MTT assay and the results were compared to the ATP assay, which is a much more sensitive and reliable assay due to …

Efficient Polyhydroxybutyrate Production From Bacillus Thuringiensis Using Sugarcane Juice Substrate, Anon Thammasittirong, Sudarat Saechow, Sutticha Na-Ranong Thammasittirong

Turkish Journal of Biology

The present study focused on the screening and optimization of biopolymer polyhydroxybutyrate (PHB) production by Bacillus spp. using cost-effective substrates. Among 602 local Bacillus isolates, Bacillus thuringiensis B417-5 produced the highest amount of PHB (2.278 g/L, 60.07% of dry cell weight, DCW). 1H NMR and FTIR analyses of the extracted polymer revealed the characteristic peaks of PHB. The optimization results showed that the highest PHB accumulation (2.768 g/L, 72.08% of DCW) was achieved when culturing B. thuringiensis B417-5 in a nitrogen-deficient medium containing 1% total sugar from sugarcane juice and 0.5% yeast extract, with a pH of 7.0 and an …

Assessment Of The Function And Expression Pattern Of Auxin Response Factor B3 In The Model Legume Plant Medicago Truncatula, Miglena Revalska, Valya Vassileva, Grigor Zehirov, Sofie Goormachtig, Anelia Iantcheva

Turkish Journal of Biology

The phytohormone auxin is a critical signal molecule, regulating fundamental processes in plant growth and development, such as shaping the root and shoot architecture, organ patterning, and nodulation. Auxin regulates plant gene expression mainly through auxin response factors (ARFs), which bind to auxin response elements in the promoter, upstream of auxin-activated genes. Here we examine and assess the function and expression pattern of a gene described as an auxin response factor, containing a DNA-binding pseudobarrel and B3 DNA-binding domains, from Medicago truncatula (MtARF-B3). For the model legume species M. truncatula, stable transgenic plants with MtARF-B3 overexpression, downregulation, and transcriptional reporters …

Combination Of Esomeprazole With Chemotherapeutics Results In More Pronounced Cytotoxic Effect Via Apoptosis On A549 Nonsmall-Cell Lung Cancer Cell Line, Arzu Yilmaztepe Oral, Haluk Barbaros Oral, Mehmet Sarimahmut, Buse Cevatemre, Güven Özkaya, Şeni̇z Korkmaz, Engi̇n Ulukaya

Turkish Journal of Biology

The vacuolar (H+)-ATPases that pump H+ from the cytoplasm to extracellular compartments can alter the pH of the tumor microenvironment. Esomeprazole can effectively inhibit vacuolar (H+)-ATPases and may increase the effectiveness of chemotherapeutics. Therefore, we used esomeprazole in combination with cisplatin, carboplatin, paclitaxel, docetaxel, gemcitabine, and vinorelbine on the A549 nonsmall-cell lung cancer cell line. Cisplatin and carboplatin combinations with esomeprazole exhibited superior cytotoxicity compared to the other selected chemotherapeutics. Low-dose combinations of esomeprazole with either cisplatin or carboplatin resulted in synergistic interaction. We examined cytotoxic activity of these combinations with the xCELLigence real-time cytotoxicity assay and detected that esomeprazole …

Cryopreservation Of Citrus Seed Via Dehydration Followedby Immersion In Liquid Nitrogen, Ergun Kaya, Fernanda Souza, Emel Yilmaz Gökdoğan, Muammer Ceylan, Maria Jenderek

Turkish Journal of Biology

An important method for plant germplasm conservation is offered by a biotechnology-based approach of cryopreservation. Cryopreservation refers to the storage of plant material at ultralow temperatures in liquid nitrogen. A procedure for cryopreservation of polyembryonic seeds was improved for selected citrus cultivars from Turkey. Seed dehydration was performed at different exposure times, in sterile conditions of a laminar flow-hood. The tested cultivars showed the highest tolerance to low temperature storage when the seeds were first dehydrated to a moisture content of 21.8% for Poncirus trifoliata Raf. x Citrus sinensis Osb. and to 17.6% for Citrus limonia Osbeck. The postcryopreservation germinability …

Heterologous Expression And Characterization Of A High Redox Potential Laccase Fromcoriolopsis Polyzona Mucl 38443, Orkun Pi̇nar, Candan Tamerler Behar, Ayten Karataş

Turkish Journal of Biology

In this study, a novel laccase gene, named as Cplcc1, and its corresponding cDNA were isolated and characterized from the Coriolopsis polyzona MUCL 38443 strain. The Cplcc1 gene consists of a 1563-bp open reading frame encoding a protein of 520 amino acids with a 20-residue putative signal peptide. The size of the Cplcc1 gene is 2106 bp and it contains ten introns and five potential N-glycosylation sites. Additionally, the isolated full-length Cplcc1 cDNA was successfully expressed in Pichia pastoris. The heterologous expression conditions were also optimized and the highest activity value increased to 800 U L-1 with 1.5% methanol, 0.8 …

Mismatch Tolerance During Homologous Recombination In Mammalian Cells, Shen Li

Theses and Dissertations

Homologous recombination (HR) serves critical roles in DNA repair to maintain genome stability, and the malfunction of HR contributes to carcinogenesis and cancer development. Current research focuses on the regulation against deleterious recombination between imperfectly matching sequences, which has been documented in certain myeloid leukemias, hereditary nonpolyposis colorectal cancers and other genetic diseases. Homology dependency of recombination was examined in cultured thymidine kinase-deficient mouse fibroblasts. Cells have chromosomal integration of DNA constructs harboring a herpes tk gene (the “recipient”) and a closely linked truncated “donor” tk sequence. The recipient was rendered non-functional by insertion of the recognition site for endonuclease …

Thermal And Behavioral Ecology Of The Mexican Beaded Lizard (Heloderma Horridum), Kerry Holcomb

All Master's Theses

Previous investigations in the field of biological thermoregulation have primarily focused on small organisms that inhabit ecosystems that are not as strongly seasonal as the tropical dry forests found along the Pacific Coast of Jalisco, Mexico. Small organisms have little or no appreciable thermal inertia, and thus, reach thermal equilibrium with their immediate surroundings relatively rapidly. In this investigation, we describe the behavioral and thermal ecology of the Mexican beaded lizard (Heloderma horridum), which commonly weighs more than 1kg. This large body size means that this species has significant thermal inertia, which, depending on the characteristics of the …

Distribution And Habitat Use Of The Golden Crab Chaceon Fenneri Off Eastern Florida Based On In Situ Submersible And Rov Observations And Potential For Impacts To Deep Water Coral/Sponge Habitat, John K. Reed, Stephanie Farrington, Charles Messing, Andrew David

Gulf and Caribbean Research

This study documents the distribution and habitat preferences of the golden crab, a commercially fished species, in relation to deep-sea coral/sponge ecosystems (DSCEs) at 200-900 m depths off eastern Florida. A total of 386 h of videotapes from 94 submersible and remotely operated vehicle (ROV) dives from 1999 to 2009, covering a total distance of 376 km, were reviewed and characterized for habitat type and presence of crabs. The DSCEs surveyed included Lophelia coral mounds, Miami Terrace, Pourtalès Terrace, and Tortugas Valleys. Video transect data also included environmental surveys of proposed deep-water routes for Liquid Natural Gas (LNG) pipelines, LNG …

The Effect Of Arginine Vasotocin On Cryoprotectant Production During Freezing In The Pacific Chorus Frog, Pseudacris Regilla, Ben Ingels

All Master's Theses

Freeze Tolerance is an adaptation seen amongst several species of amphibians as a way of surviving during wintering months. Use of cryoprotectants is seen in all freeze tolerant species (glucose/glycerol). Synthesis and transportation mechanisms that regulate this process are not yet fully understood. Arginine vasotocin is a neurohypophyseal peptide known to have glycogenolytic effects as well as regulate several key processes involved in fluid and solute transportation. Although one prior study suggested that AVT is not involved in responses to freezing, I measured AVT levels during freezing and injected an AVT antagonist to see if it would affect the production …

The Hero Organism: Advancing The Embodiment Of Heroism Thesis In The Twenty-First Century, Olivia Efthimiou

Scott T. Allison

Whole Genome Dna Methylation Sequencing Of The Chicken Retina, Cornea And Brain, Isac Lee, Bejan A. Rasoul, Ashton S. Holub, Alannah Lejeune, Raymond A. Enke, Winston Timp

Ray Enke Ph.D.

No abstract provided.

Genomics Rna-Seq Analysis Part 1-Cyverse De, Fastqc, Trimmomatic (Updated 11/17), Ray A. Enke, Melika Rahmani-Mofrad

Ray Enke Ph.D.

Cutting Edge: Promoting International Collaboration And Creativity In Doctoral Students, Christopher M. Groen, Cormac Mcgrath, Katherine A. Campbell, Cecilia Götherström, Anthony J. Windebank, Natalia Landázuri

Katherine Campbell, PhD

No abstract provided.