Units for Promoter Measurement in Mammalian Cells

The purpose of this RFC is to provide units for the characterization of promoter strength for use in mammalian cells. RMPU is mRNA based and directly proportional to PoPS, whereas REU is protein based and not proportional to PoPS

Large-Scale Intentional Interventions into the Climate System? Assessing the Climate Engineering Debate

Scoping report conducted on behalf of the German Federal Ministry of Education and Research (BMBF), Kiel Earth Institute, Kiel

Comparative de novo assembly and annotation of mantle tissue transcriptomes from the Mytilus edulis species complex (M. edulis, M. galloprovincialis, M. trossulus)

Mytilus mussels (Mytilus edulis (ME), M. trossulus (MT), and M. galloprovincialis (MG)) are of interest in many fields of marine science and have been used as model in evolutionary research. For instance, they form mosaic hybrid zones or hybrid swarms in areas of secondary contact and hence are suited to address questions related to the evolution of reproductive barriers, adaptive hybridization or speciation. While existing genomic information mostly focuses on single species (ME, MG), this project generated RNA seq data of all three species from allopatric populations, i.e. samples representing genetically pure specimens. We investigated adult mantle tissue (four specimens per species), which is functionally involved in processes such as reproduction or biomineralization. The project provides three assembled transcriptomes (post filtering total transcript numbers for ME: 353339, MT: 437827, MG: 290267) representing genes annotated to at least 40 level 2 GO-terms (number (percentage) of annotated transcripts for ME: 44434 (12.6%), MT: 43960 (10%), MG: 60064 (20.7%)). Annotation showed that the most abundant 40 GO-terms are equally well covered by contigs of the three Mytilus transcriptomes. Therefore, this project lays a basis for evolutionary research by providing candidate genes representing various molecular functions such as reproduction, cellular processes or immune response. The potential of the new transcriptomes to address evolutionary questions is further exemplified by a pilot study on ME and MT transcriptomes that used reciprocal blast to identify 7652 one-to-one orthologue pairs of transcript

Preference for attractiveness and thinness in a partner: Influence of internalization of the thin ideal and shape/weight dissatisfaction in heterosexual women, heterosexual men, lesbians, and gay men

This study assesses whether characteristics of one’s own body image influences preferences of attractiveness in a partner. The role of gender and sexual orientation is also considered. Heterosexual women (n = 67), lesbian women (n = 73), heterosexual men (n = 61) and gay men (n = 82) participated in an internet survey assessing attitudes towards the body and preferences of attractiveness in a partner. Men in particular were found to prefer attractive partners, regardless of sexual orientation. Weight/shape dissatisfaction was found to be a negative predictor for heterosexual men and women. For gay men, preferences were better explained by internalization and weight/shape dissatisfaction. No such associations were found in the lesbian group. Levels of weight/shape dissatisfaction and internalization of socio-cultural slenderness ideals influence expectations of thinness and attractiveness in a partner with this effect being modified by gender and sexual orientation

Cytosolic Peroxidases Protect the Lysosome of Bloodstream African Trypanosomes from Iron-Mediated Membrane Damage

<div><p>African trypanosomes express three virtually identical non-selenium glutathione peroxidase (Px)-type enzymes which preferably detoxify lipid-derived hydroperoxides. As shown previously, bloodstream <i>Trypanosoma brucei</i> lacking the mitochondrial Px III display only a weak and transient proliferation defect whereas parasites that lack the cytosolic Px I and Px II undergo extremely fast lipid peroxidation and cell lysis. The phenotype can completely be rescued by supplementing the medium with the α-tocopherol derivative Trolox. The mechanism underlying the rapid cell death remained however elusive. Here we show that the lysosome is the origin of the cellular injury. Feeding the <i>px I–II</i> knockout parasites with Alexa Fluor-conjugated dextran or LysoTracker in the presence of Trolox yielded a discrete lysosomal staining. Yet upon withdrawal of the antioxidant, the signal became progressively spread over the whole cell body and was completely lost, respectively. <i>T. brucei</i> acquire iron by endocytosis of host transferrin. Supplementing the medium with iron or transferrin induced, whereas the iron chelator deferoxamine and apo-transferrin attenuated lysis of the <i>px I–II</i> knockout cells. Immunofluorescence microscopy with MitoTracker and antibodies against the lysosomal marker protein p67 revealed that disintegration of the lysosome precedes mitochondrial damage. <i>In vivo</i> experiments confirmed the negligible role of the mitochondrial peroxidase: Mice infected with <i>px III</i> knockout cells displayed only a slightly delayed disease development compared to wild-type parasites. Our data demonstrate that in bloodstream African trypanosomes, the lysosome, not the mitochondrion, is the primary site of oxidative damage and cytosolic trypanothione/tryparedoxin-dependent peroxidases protect the lysosome from iron-induced membrane peroxidation. This process appears to be closely linked to the high endocytic rate and distinct iron acquisition mechanisms of the infective stage of <i>T. brucei</i>. The respective knockout of the cytosolic <i>px I–II</i> in the procyclic insect form resulted in cells that were fully viable in Trolox-free medium.</p></div

Lysosomal disintegration precedes damage of the mitochondrion.

<p>The <i>px I–II</i>^−/− BS cells were kept for the indicated times at 37°C in medium ± Trolox and then subjected to immunofluorescence analysis. <b>A.</b> MitoTracker staining (left), overlay of the signals for MitoTracker (red), p67 (green), and DAPI (blue) (middle), and phase contrast images (right). <b>B.</b> Quantitative analysis of the staining pattern of the cells (for details, see text). The phenotypes visible in the respective pictures in (<b>A</b>) are highlighted by bold numbers. For each time point, at least 194 cells were inspected. The data are representative of two independent sets of experiments giving very similar results. (Scale bar: 10 µm).</p

Withdrawal of Trolox results in morphological changes of the <i>px I–II</i>^−/− BS cells.

<p><b>A.</b> Living parasites were fed at 37°C with Alexa Fluor-488 conjugated dextran and then kept at RT in medium with (+) or without (−) 100 µM Trolox as outlined under <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004075#s4" target="_blank">Materials and Methods</a>. On the left site, representative cells for the three different phenotypes observed in the remaining intact and fluorescent parasites are shown. The pictures were taken from cells incubated (1) 1 h, + Trolox, (2) 1 and 2 h, - Trolox, and (3) 2 h, - Trolox. On the right site, the quantitative analysis is provided. At each time point, ≥60 parasites were analyzed in three independent experiments and the mean ± SD was calculated. <b>B.</b> LysoTracker Green staining of living parasites incubated for the indicated times at 37°C in the presence or absence of Trolox. <b>C.</b> Immunofluorescence analysis of cells stained with antibodies against p67 (green) and DAPI (blue) to visualize nuclear (large dot) and kinetoplast (small dot) DNA (upper panel) and the corresponding phase contrast pictures (lower panel). At each time point, the p67 signal of at least 130 parasites was analyzed in each of three independent experiments and the mean ± SD was calculated (below). (Scale bar: 10 µm).</p

Lysis of the <i>px I–II</i>^−/− BS cells is temperature-dependent.

<p>The <i>px I–II^−/−</i> parasites were seeded at a density of 5–9×10⁵ cells/ml in standard HMI-9 medium (which contains 10% FCS) supplemented ±100 µM Trolox. The cells were incubated at 37°C, 21°C, and 9°C, respectively. At the indicated time points, living cells were counted. The values represent the mean ± SD of three independent experiments.</p

Infectivity of <i>px III</i>^−/− and WT <i>T. brucei</i>.

<p><b>A.</b> and <b>B.</b> Female BALB/cJ mice (n = 6/group) were infected intraperitoneally with 10⁴ WT parasites or <i>px III</i>^−/− cells that, prior to infection, had been cultivated in medium supplemented with 100 µM Trolox, and <b>C.</b> and <b>D.</b> in medium without Trolox. <b>E.</b> and <b>F.</b> Mice (n = 3/group) were inoculated with <i>px III</i>^−/− and WT parasites isolated from infected animals (for details see <a href="http://www.plospathogens.org/article/info:doi/10.1371/journal.ppat.1004075#s4" target="_blank">Materials and Methods</a>). <b>A.</b>, <b>C.</b>, and <b>E.</b> Kaplan-Meyer plots for animal survival, <b>B.</b>, <b>D.</b>, and <b>F.</b> Average parasite load in blood samples taken from the animals at the indicated times. All data are the mean value ± SD.</p