LIPID METABOLISM IN \u3ci\u3eTrypanosoma brucei\u3c/i\u3e: MOLECULAR CHARACTERIZATION OF FATTY ACID SYNTHESIS AND UPTAKE

My doctoral studies focused on the fatty acid metabolism of the deadly protozoan parasite, Trypanosoma brucei. Fatty acid metabolism in T. brucei can be broadly divided into two pathways, synthesis and uptake. In Chapters 2-4 I describe experiments investigating the parasite\u27s fatty acid synthesis pathway. Chapter 2 contains the initial characterization of acetyl-CoA carboxylase (ACC) in T. brucei. Knockdown of TbACC by RNA interference (RNAi) reduced parasite virulence in a mouse model, suggesting that TbACC has the potential to be utilized as a drug target. Chapters 3 and 4 explore the effects of two known ACC inhibitors, the aryloxyphenoxypropionate herbicide, haloxyfop and the green tea catechin, (−)-epigallocatechin-3-gallate (EGCG) on TbACC activity and parasite growth. Both compounds inhibited TbACC enzymatic activity and parasite growth in vitro. In Chapters 5 and 6 contain research that utilizes forward and reverse-genetic techniques to study T. brucei fatty acid uptake. In Chapter 5 I begin to characterize the role of the parasite\u27s acyl-CoA synthetase genes in fatty acid uptake and growth. Further, I demonstrate that fatty acid uptake is in part a protein mediated process. Chapter 6 describes an RNAi screen for genes involved in T. brucei fatty acid uptake. Together these studies build upon our knowledge of the unique fatty acid metabolism of T. brucei, bringing us one step closer to a potential cure for this horrible disease

Long-term balancing selection at the Phosphorus Starvation Tolerance 1 (PSTOL1) locus in wild, domesticated and weedy rice (Oryza)

Dry Shoot Weights of PSTOL1 genotypes grown in low and high phosphorus conditions. Plants were measured after 21 days in high phosphorus (black) and low phosphorus (grey) media. (PDF 72 kb

The genomics of domestication special issue editorial

Domestication has been of major interest to biologists for centuries, whether for creating new plants and animal types or more formally exploring the principles of evolution. Such studies have long used combinations of phenotypic and genetic evidence. Recently, the advent of a large number of genomes and genomic tools across a wide array of domesticated plant and animal species has reinvigorated the study of domestication. These genomic data, which can be easily generated for nearly any species, often provide great insight with or without a reference genome. The comparison of genome wide data from domestic and wild species has ignited a wave of insight into human, plant, and animal history with a new range of questions becoming accessible. With this in mind, this issue of Evolutionary Applications includes eleven papers covering a wide range of perspectives and methodologies relevant to understanding genomic variation under domestication

Control of intestinal stem cell function and proliferation by mitochondrial pyruvate metabolism.

Most differentiated cells convert glucose to pyruvate in the cytosol through glycolysis, followed by pyruvate oxidation in the mitochondria. These processes are linked by the mitochondrial pyruvate carrier (MPC), which is required for efficient mitochondrial pyruvate uptake. In contrast, proliferative cells, including many cancer and stem cells, perform glycolysis robustly but limit fractional mitochondrial pyruvate oxidation. We sought to understand the role this transition from glycolysis to pyruvate oxidation plays in stem cell maintenance and differentiation. Loss of the MPC in Lgr5-EGFP-positive stem cells, or treatment of intestinal organoids with an MPC inhibitor, increases proliferation and expands the stem cell compartment. Similarly, genetic deletion of the MPC in Drosophila intestinal stem cells also increases proliferation, whereas MPC overexpression suppresses stem cell proliferation. These data demonstrate that limiting mitochondrial pyruvate metabolism is necessary and sufficient to maintain the proliferation of intestinal stem cells

Hubungan Kandidiasis Intertriginosa dan Diabetes Melitus Tipe 2 di Poliklinik Kulit dan Kelamin RSUD Dokter Soedarso Pontianak pada Tahun 2012

Background. Intertriginous candidiasis is a type of cutaneous candidiasiswhich is located at the axila, inguinal, intergluteal, inframammary,interdigitalis, glands penis, and umbilicus. One of the risk factors ofintertriginous candidiasis patient is people with diabetes mellitus (DM).The increase of glucose concentration makes more susceptible frominfection. Objective. Define the association between intertriginouscandidiasis and DM type 2. Method. This research was a case controlstudy which took place in Dermatovenereology Outpatient Clinic RSUD dr.Soedarso from June until November 2013. The minimum sample for thisresearch was 126 people and divided into two groups. The case groupconsisted of 63 people and the control group consisted of 63 people. Thesubjects were selected by using consecutive sampling and analyzed bychi-square test. Result. There was an association between intertriginouscandidiasis with DM type 2 (p= 0,01). Odds Ratio (OR) value of thisresearch was 2,621 (IK 95% : 1,246 5,516). Conclusion. Intertriginouscandidiasis is associated with DM type 2 and people with DM type 2 havea possibility of 2,621 times higher risk of acquiring intertriginouscandidiasis than people without diabetes mellitus

A PSTOL-like gene, TaPSTOL, controls a number of agronomically important traits in wheat

Background Phosphorus (P) is an essential macronutrient for plant growth, and is required in large quantities by elite varieties of crops to maintain yields. Approximately 70% of global cultivated land suffers from P deficiency, and it has recently been estimated that worldwide P resources will be exhausted by the end of this century, increasing the demand for crops more efficient in their P usage. A greater understanding of how plants are able to maintain yield with lower P inputs is, therefore, highly desirable to both breeders and farmers. Here, we clone the wheat (Triticum aestivum L.) homologue of the rice PSTOL gene (OsPSTOL), and characterize its role in phosphate nutrition plus other agronomically important traits. Results TaPSTOL is a single copy gene located on the short arm of chromosome 5A, encoding a putative kinase protein, and shares a high level of sequence similarity to OsPSTOL. We re-sequenced TaPSTOL from 24 different wheat accessions and (3) three T. durum varieties. No sequence differences were detected in 26 of the accessions, whereas two indels were identified in the promoter region of one of the durum wheats. We characterised the expression of TaPSTOL under different P concentrations and demonstrated that the promoter was induced in root tips and hairs under P limiting conditions. Overexpression and RNAi silencing of TaPSTOL in transgenic wheat lines showed that there was a significant effect upon root biomass, flowering time independent of P treatment, tiller number and seed yield, correlating with the expression of TaPSTOL. However this did not increase PUE as elevated P concentration in the grain did not correspond to increased yields. Conclusions Manipulation of TaPSTOL expression in wheat shows it is responsible for many of the previously described phenotypic advantages as OsPSTOL except yield. Furthermore, we show TaPSTOL contributes to additional agronomically important traits including flowering time and grain size. Analysis of TaPSTOL sequences from a broad selection of wheat varieties, encompassing 91% of the genetic diversity in UK bread wheat, showed that there is very little genetic variation in this gene, which would suggest that this locus may have been under high selection pressure

Validation of <i>N</i>-myristoyltransferase as Potential Chemotherapeutic Target in Mammal-Dwelling Stages of <i>Trypanosoma cruzi</i>

BACKGROUND:Trypanosoma cruzi causes Chagas disease, an endemic and debilitating illness in Latin America. Lately, owing to extensive population movements, this neglected tropical disease has become a global health concern. The two clinically available drugs for the chemotherapy of Chagas disease have rather high toxicity and limited efficacy in the chronic phase of the disease, and may induce parasite resistance. The development of new anti-T. cruzi agents is therefore imperative. The enzyme N-myristoyltransferase (NMT) has recently been biochemically characterized, shown to be essential in Leishmania major, Trypanosoma brucei, and T. cruzi¸ and proposed as promising chemotherapeutic target in these trypanosomatids. METHODOLOGY/PRINCIPAL FINDINGS:Here, using high-content imaging we assayed eight known trypanosomatid NMT inhibitors, against mammal-dwelling intracellular amastigote and trypomastigote stages and demonstrated that three of them (compounds 1, 5, and 8) have potent anti-proliferative effect at submicromolar concentrations against T. cruzi, with very low toxicity against human epithelial cells. Moreover, metabolic labeling using myristic acid, azide showed a considerable decrease in the myristoylation of proteins in parasites treated with NMT inhibitors, providing evidence of the on-target activity of the inhibitors. CONCLUSIONS/SIGNIFICANCE:Taken together, our data point out to the potential use of NMT inhibitors as anti-T. cruzi chemotherapy

Analytical methods applied to diverse types of Brazilian propolis

Propolis is a bee product, composed mainly of plant resins and beeswax, therefore its chemical composition varies due to the geographic and plant origins of these resins, as well as the species of bee. Brazil is an important supplier of propolis on the world market and, although green colored propolis from the southeast is the most known and studied, several other types of propolis from Apis mellifera and native stingless bees (also called cerumen) can be found. Propolis is usually consumed as an extract, so the type of solvent and extractive procedures employed further affect its composition. Methods used for the extraction; analysis the percentage of resins, wax and insoluble material in crude propolis; determination of phenolic, flavonoid, amino acid and heavy metal contents are reviewed herein. Different chromatographic methods applied to the separation, identification and quantification of Brazilian propolis components and their relative strengths are discussed; as well as direct insertion mass spectrometry fingerprinting