Evolution of hydrogenosomes in anaerobic ciliates

Phd ThesisWithin ciliates (protozoa of the phylum Ciliophora), anaerobic species are widespread and typically possess organelles which produce H2 and ATP, called hydrogenosomes. Hydrogenosomes are mitochondrial homologues and are a product of evolutionary convergence, having been found in wide-ranging and diverse anaerobic eukaryotes. Ciliates seem to have evolved hydrogenosomes on multiple occasions from the mitochondria of their aerobic ancestors. The hydrogenosomes of the ciliate Nyctotherus ovalis were studied in detail previously but little is known about the hydrogenosomes from other ciliate species. In the present study seven species of ciliate, Cyclidium porcatum, Metopus contortus, Metopus es, Metopus striatus, Nyctotherus ovalis, Plagiopyla frontata and Trimyema sp. were cultured and their hydrogenosomes were investigated using genomic and transcriptomic sequencing from whole genome amplifications from single and small numbers of isolated cells. The data were then used to reconstruct putative hydrogenosome metabolic pathways. Components of these pathways are typically encoded by the ciliate nuclear genomes but Nyctotherus ovalis, Metopus contortus, Metopus es, Metopus striatus and Cyclidium porcatum have also retained mitochondrial (now hydrogenosomal) genomes which were sequenced for the first time. The most complete of these genomes were from Nyctotherus ovalis and Metopus contortus. These have both retained genes for proton-pumping subunits of the electron transport chain Complex I and ribosomal subunits needed for their synthesis. The ciliates Plagiopyla frontata and Trimyema sp. appear to have completely lost the organelle genome during the conversion of mitochondria into hydrogenosomes. The ciliate hydrogenosomes for which the most data was obtained appear to have retained some of the enzymes needed to produce energy by substrate-level phosphorylation but some species have also retained a partial electron transport chain and Cyclidium porcatum has retained nuclear encoded subunits of the mitochondrial F1F0 ATP synthase complex. Nuclear genes encoding enzymes that play a key role in H2 production, FeFe-hydrogenase, pyruvate: ferredoxin oxidoreductase and pyruvate: NADPH+ oxidoreductase, were also sequenced from the sampled ciliates and their evolutionary origins were investigated using phylogenies. These suggest that ciliate FeFe-hydrogenases are monophyletic and iii have a separate bacterial origin from FeFe-hydrogenases in other eukaryotes. No evidence was found to support an alpha-proteobacteria or mitochondrial ancestry of these enzymes as predicted by the Hydrogen Hypothesis (Martin and Müller, 1998). Each of the ciliates investigated contained methanogenic Archaea endosymbionts, which can consume the H2 produced by the hydrogenosomes. Some of these endosymbionts were identified to the species-level. The associations they have formed with their hosts appear to be stable over short time-scales but not over longer evolutionary periods, as closely related ciliates like Nyctotherus ovalis and Metopus contortus do not have closely related endosymbionts, providing no evidence for long-term co-speciation

Monoclonal antibodies for copper-64 PET dosimetry and radioimmunotherapy

BACKGROUND: We previously described a two-antibody model of (64)Cu radioimmunotherapy to evaluate low-dose, solid-tumor response. This model was designed to test the hypothesis that cellular internalization is critical in causing tumor cell death by mechanisms in addition to radiation damage. The purpose of the present study was to estimate radiation dosimetry for both antibodies (mAbs) using positron emission tomography (PET) imaging and evaluate the effect of internalization on tumor growth. RESULTS: Dosimetry was similar between therapy groups. Median time to tumor progression to 1 g ranged from 7–12 days for control groups and was 32 days for both treatment groups (p < 0.0001). No statistically significant difference existed between any control group or between the treatment groups. MATERIAL AND METHODS: In female nude mice bearing LS174T colon carcinoma xenografts, tumor dosimetry was calculated using serial PET images of three mice in each group of either internalizing (64)Cu-labeled DOTA-cBR96 (DOTA = 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) or non-internalizing (64)Cu-labeled DOTA-cT84.66 from 3 to 48 h. For the therapy study, controls (n = 10) received saline, DOTA-cBR96 or DOTA-cT84.66. Treatment animals (n = 9) received 0.890 mCi of (64)Cu-labeled DOTA-cBR96 or 0.710 mCi of (64)Cu-labeled DOTA-cT84.66. Tumors were measured daily. CONCLUSIONS: PET imaging allows the use of (64)Cu for pre-therapy calculation of tumor dosimetry. In spite of highly similar tumor dosimetry, an internalizing antibody did not improve the outcome of (64)Cu radioimmunotherapy. Radio-resistance of this tumor cell line and copper efflux may have confounded the study. Further investigations of the therapeutic efficacy of (64)Cu-labeled mAbs will focus on interaction between (64)Cu and tumor suppressor genes and copper chaperones

Ernst Freund as Precursor of the Rational Study of Corporate Law

Gindis, David, Ernst Freund as Precursor of the Rational Study of Corporate Law (October 27, 2017). Journal of Institutional Economics, Forthcoming. Available at SSRN: https://ssrn.com/abstract=2905547, doi: https://dx.doi.org/10.2139/ssrn.2905547The rise of large business corporations in the late 19th century compelled many American observers to admit that the nature of the corporation had yet to be understood. Published in this context, Ernst Freund's little-known The Legal Nature of Corporations (1897) was an original attempt to come to terms with a new legal and economic reality. But it can also be described, to paraphrase Oliver Wendell Holmes, as the earliest example of the rational study of corporate law. The paper shows that Freund had the intuitions of an institutional economist, and engaged in what today would be called comparative institutional analysis. Remarkably, his argument that the corporate form secures property against insider defection and against outsiders anticipated recent work on entity shielding and capital lock-in, and can be read as an early contribution to what today would be called the theory of the firm.Peer reviewe

Supplement I to Bulletin 21

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Supplement II to Bulletin 21

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Investigations of chemical reactions involved in water purification, 1920-1925

At head of title: State of Illinois. Department of registration and education. Division of the state water survey. A.M. Buswell, chief ...Bibliography: p. 128-133.Enumeration continues from preceding title

The Impact of Climate Change on Virginia\u27s Coastal Areas

As part of HJ47/SJ47 (2020), the Virginia General Assembly directed the Joint Commission on Technology and Science (JCOTS) to study the “safety, quality of life, and economic consequences of weather and climate-related events on coastal areas in Virginia.” In pursuit of this goal, the commission was to “accept any scientific and technical assistance provided by the nonpartisan, volunteer Virginia Academy of Science, Engineering, and Medicine (VASEM). VASEM convened an expert study board with representation from the Office of the Governor, planning district commissions in coastal Virginia, The Port of Virginia, the Virginia Economic Development Partnership, state universities, private industry, and law firms. In producing the report, the board followed methods similar to those used by the National Academies of Science, Engineering, and Medicine by convening an expert committee tasked with studying and reporting on the topic. As a result, the report represents the views and perspectives of the study board members but was not submitted for public review or comment. This report is the product of those efforts. It finds that climate change will have an increasingly disruptive effect on people living in Virginia’s coastal areas during the 21st century — and that these disruptions will have repercussions across the Commonwealth. It includes an explanation of the physical forces driving climate change, an analysis of the current and projected effects of climate change on the Commonwealth, perspectives that legislators might consider as they face these challenges, and recommendations that could help Virginia implement more productive and effective strategies to address them

Killer-cell immunoglobulin-like receptor genotyping and HLA killer-cell immunoglobulin-like receptor-ligand identification by real-time polymerase chain reaction.

The effector function of natural killer (NK) cells is modulated by surface expression of a range of killer-cell immunoglobulin-like receptors (KIRs) that interact with human leukocyte antigen (HLA) class I ligands. We describe the use of real-time polymerase chain reaction (PCR) assays that allow easy and quick detection of 16 KIR genes and the presence/absence of KIR-ligands based on allelic discrimination at codon 80 in the HLA-A/B Bw4 and HLA-C C1/C2 genes. These methods overcome the tedious and expensive nature of conventional KIR genotyping and HLA class I typing using sequence-specific primer (SSP) PCR, sequence-specific oligonucleotide (SSO) hybridization or sequence-based typing (SBT). Using these two cost-effective assays, we measured the frequencies of KIRs, KIR-ligands and KIR/KIR-ligand pairs in a cohort of Black women recruited in South Africa