Proteome-wide analysis of Trypanosoma cruzi exponential and stationary growth phases reveals a subcellular compartment-specific regulation

Trypanosoma cruzi, the etiologic agent of Chagas disease, cycles through different life stages characterized by defined molecular traits associated with the proliferative or differentiation state. In particular, T. cruzi epimastigotes are the replicative forms that colonize the intestine of the Triatomine insect vector before entering the stationary phase that is crucial for differentiation into metacyclic trypomastigotes, which are the infective forms of mammalian hosts. The transition from proliferative exponential phase to quiescent stationary phase represents an important step that recapitulates the early molecular events of metacyclogenesis, opening new possibilities for understanding this process. In this study, we report a quantitative shotgun proteomic analysis of the T. cruzi epimastigote in the exponential and stationary growth phases. More than 3000 proteins were detected and quantified, highlighting the regulation of proteins involved in different subcellular compartments. Ribosomal proteins were upregulated in the exponential phase, supporting the higher replication rate of this growth phase. Autophagy-related proteins were upregulated in the stationary growth phase, indicating the onset of the metacyclogenesis process. Moreover, this study reports the regulation of N-terminally acetylated proteins during growth phase transitioning, adding a new layer of regulation to this process. Taken together, this study reports a proteome-wide rewiring during T. cruzi transit from the replicative exponential phase to the stationary growth phase, which is the preparatory phase for differentiation

Salivary α-Amylase of Stem Borer Hosts Determines Host Recognition and Acceptance for Oviposition by Cotesia spp. (Hymenoptera, Braconidae)

Foraging insect parasitoids use specific chemical cues to discriminate between host and non-host species. Several compounds have been identified in “host location and acceptance.” However, nothing is known about the molecular variations in these compounds that could account for host-range differences between parasitoid species. In a previous study, it was shown that during the host-finding process, contact between the braconid Cotesia flavipes and its host is crucial, and that α-amylase of oral secretions from the host plays a key role for host acceptance and oviposition by the parasitoid. The present study sought to establish whether the variations in this enzyme could explain specific host recognition in different host-parasitoid associations. Different species and populations of the C. flavipes complex specialized on graminaceous lepidopteran stemborers were used. Electrophoresis of α-amylase revealed different isoforms that mediate the parasitoid's oviposition acceptance and preference for a specific host. This discovery opens up new avenues for investigating the evolutionary processes at play in chemically-mediated host specialization in the species-rich Cotesia genus

The seventh national communication of Malta under the United Nations framework convention on climate change

This is the fourth time that Malta is submitting a National Communication under the United Nations Framework Convention on Climate Change (UNFCCC), following the submission of a First National Communication in 2004 and a Second National Communication in 2010. This is also the second time that Malta is submitting such a Communication since its accession to Annex I status under the Convention, the first two submissions having been made as a non-Annex I Party. Emission reduction or limitation commitments applicable to Malta Malta’s status under the Convention up to the time it applied for accession to Annex I, and with that accession being conditional to not taking on quantified emission limitation or reduction targets for the first commitment period of the Kyoto Protocol, meant that until 2012 Malta was not subject to an economy-wide greenhouse gas related obligation under the Protocol. This however did not mean that Malta had no obligations to limit or reduce emissions from anthropogenic activities taking place in the country. In line with, Malta will be contributing its fair share of the EU’s unconditional commitment under the Convention to reduce emissions by 20% below 1990 levels by 2020. This is in line with the target inscribed in the amendments to the Kyoto Protocol (the Doha Amendments), that will be jointly fulfilling the second commitment period with the other Union member states; therefore, emissions from the aforementioned power plants remain subject to compliance with EU Emissions Trading Scheme provisions, while the Effort-Sharing Decision target is the principal emissions mitigation obligation that the country has until 2020, for all other greenhouse gas emissions. The major point sources of greenhouse gas emissions in Malta, namely the electricity generation plants have been, since of 2005, subject to the EU Emissions Trading Scheme, whereby they are required to surrender allowances in respect of emissions of carbon dioxide. Emissions of greenhouse gases not covered by the EU Emissions Trading Scheme, are subject to an overall limit under the so-called Effort-Sharing Decision. Under this decision, Malta must limit such greenhouse gases to not more than 5% over emission levels in 2005, by 2020. The EU is already looking towards the longer-term future, with the 2030 climate and energy framework providing for a 40% domestic reduction target for 2030. Legislative implementation of this goal is currently under discussion at EU level.peer-reviewe

Comprehensive transcriptome of the maize stalk borer, Busseola fusca, from multiple tissue types, developmental stages, and parasitoid wasp exposures

International audienc

Echinoderms from the Museum of Zoology from the Universidad de Costa Rica

El Museo de Zoología de la Universidad de Costa Rica (MZUCR) se funda en 1966 y alberga la colección de organismos vertebrados e invertebrados más completa de Costa Rica. El MZUCR cuenta actualmente con 24 colec-ciones que contienen más de cinco millones de especíme-nes, y más de 13 000 especies identificadas. Las primeras colecciones datan 1960 e incluyen peces, reptiles, anfibios, poliquetos, crustáceos y equinodermos. Para este último grupo, el MZUCR posee un total de 157 especies, en 1 173 lotes y 4 316 ejemplares. Estas 157 especies representan el 54% del total de especies de equinodermos que posee Costa Rica (293 especies). El resto de especies están repar-tidas en las siguientes instituciones: Academia de la Cien-cias de California (CAS) (4.8%), Instituto Oceanográfico Scripps (SIO) (5.2%), en la Colección Nacional de equino-dermos “Dra. Ma. Elena Caso” de la Universidad Nacional Autónoma de México (ICML-UNAM) (12.7%), Museo de Zoología Comparada de Harvard (MZC) (19.2%), y en el Museo Nacional de Historia Natural del Instituto Smithso-niano (USNM) (35.1%). Es posible que haya material de Costa Rica en el Museo de Historia Natural de Dinamarca (NCD) y en el Museo de Historia Natural de los Ángeles (LACM), sin embargo, no hubo acceso a dichas coleccio-nes. A su vez hay 9.6% de especies que no aparecen en ningún museo, pero están reportadas en la literatura. Con base en esta revisión de colecciones se actualizó el listado taxonómico de equinodermos para Costa Rica que consta de 293 especies, 152 géneros, 75 familias, 30 órdenes y cinco clases. La costa Pacífica de Costa Rica posee 153 especies, seguida por la isla del Coco con 134 y la costa Caribe con 65. Holothuria resultó ser el género más rico con 25 especies.The Museum of Zoology, Universidad de Costa Rica (MZUCR) was founded in 1966 and houses the most complete collection of vertebrates and invertebrates in Costa Rica. The MZUCR currently has 24 collections containing more than five million specimens, and more than 13 000 species. The earliest collections date back to 1960 and include fishes, reptiles, amphibians, polychaetes, crustaceans and echinoderms. For the latter group, the MZUCR has a total of 157 species, in 1 173 lots and 4 316 specimens. These 157 species represent 54% of the total species of echino-derms from Costa Rica. The remaining species are distributed in the following institutions: California Academy of Sciences (CAS) (4.8%), Scripps Oceanographic Institute (SIO) (5.2%), National Echinoderm Collection “Dr. Ma. Elena Caso” from the National Autonomous University of Mexico (ICML-UNAM) (12.7%), the National Museum of Natural History, Smithsonian Institute (USNM) (35.1%), and the Harvard Museum of Comparative Zoology (19.2%). There may be material from Costa Rica in the Natural History Museum of Denmark (NCD) and the Natural History Museum of Los Angeles (LACM), however, there was no access to such collections. There are 9.6% that do not appear in museums, but are reported in the literature. Based on this revision, the taxonomic list of echinoderms for Costa Rica is updated to 293 species, 152 genera, 75 families, 30 orders and 5 classes. The Pacific coast of Costa Rica has 153 species, followed by the Isla del Coco with 134 and the Caribbean coast with 65. Holothuria is the most diverse genus with 25 species.UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de BiologíaUCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Ciencias del Mar y Limnología (CIMAR)UCR::Vicerrectoría de Investigación::Unidades de Investigación::Artes y Letras::Museo de la Universidad de Costa Ric

The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Dissecting the pathogenesis of Chagas disease by deep glycomics and glycoproteomics approaches.

Trypanosoma cruzi é um protozoário unicelular responsável pela doença tropical negligenciada (DTN) denominada doença de Chagas (tripanossomíase americana), uma doença endêmica em 21 países da América do Sul e Central. A doença de Chagas também se apresenta como uma preocupação emergente de saúde global com casos reportados na América do Norte, Europa, Japão e Austrália. A doença pode apresentar diferentes formas clínicas e as opções de tratamentos disponíveis, Benznidazol e Nifurtimox, são limitadas devido à alta toxicidade, efeitos colaterais e reduzida eficácia do tratamento devido à resistência apresentada pelos parasitas. As cepas de T. cruzi são geneticamente diversas com implicações na patogenicidade e virulência, progressão e desfecho da doença, além da susceptibilidade/resistência a drogas. Nesta tese, será apresentada a aplicação da espectrometria de massas para elucidar os principais aspectos moleculares de T. cruzi, incluindo: 1) modulação sistemática do proteoma entre estágios e entre diferentes cepas e espécies de parasitas e 2) modulação de modificações pós-traducionais (PTMs) de T. cruzi. Relativo à parte proteômica, será apresentado A) A modulação de proteínas de membrana da cepa CL14 de T. cruzi durante a progressão da fase exponencial para a fase estacionária a fim de elucidar as mudanças moleculares durante os estágios iniciais de metaciclogênese e B) análise global de perfis de expressão de proteínas entre cepas de T. cruzi e espécies de tripanossomas intimamente relacionadas. A análise de PTMs por espectrometria de massas dará enfoque A) na modulação da S-nitrosilação de proteínas em tripomastigotas seguida pela incubação com a matriz extracelular do hospedeiro, B) na análise global das mudanças conformacionais de glicoproteínas e C) no mapeamento do glicoproteoma (N- e O-ligados), glicoma (N- e O-glicanos) e suas respectivas expressões diferenciais entre as cepas de T. cruzi e espécies de tripanossomas intimamente relacionadas. Considerando todos os achados, esta tese mostra a importância da proteômica no estudo das mudanças moleculares na expressão de proteínas e modificações pós-traducionais durante a interação patógeno-hospedeiro. Especificamente, os métodos desenvolvidos e implementados neste estudo serão úteis para a comunidade científica para estudar, além de infecções pelo T. cruzi, outros sistemas biológicos. Finalmente, este trabalho elucida o papel de proteínas específicas e modificações pós-traducionais, alvos para o diagnóstico e terapia da doença de Chagas.Trypanosoma cruzi is a unicellular protozoan parasite responsible for the neglected tropical disease (NTD) termed Chagas disease (American Trypanosomiasis), a disease endemic in 21 South and Central American countries. Chagas disease is also an emerging global health concern with cases reported in Northern America, Europe, Japan, and Australia. The disease presents in variable clinical forms, and the treatment options available, Benznidazole and Nifurtimox are limited by high toxicities, side effects and decreasing treatment efficiency due to resistance by T. cruzi parasites. T. cruzi strains are genetically diverse, with implications on pathogenicity and virulence, disease progression and outcome, and drug susceptibility/resistance. In this thesis, the application of mass spectrometry to elucidate key T. cruzi molecular aspects will be presented, including: 1) system-wide modulation of the proteome between growth stages and between different parasite strains and species, and 2) modulation of T. cruzi posttranslational modifications (PTMs). For the proteomics part, A) the modulation of membrane proteins of T. cruzi CL14 strain during progression from exponential to stationary growth phases to elucidate the molecular changes during the early stages of metacyclogenesis, and B) the systems-wide protein expression profiles between T. cruzi strains and closely related trypanosome species will be presented. Analysis of PTMs by mass spectrometry will focus on: A) the modulation of T. cruzi trypomastigote protein S-nitrosylation following incubation with host extracellular matrix, B) the systems-wide analysis of glycoprotein conformational changes, and C) the mapping of intact N- and O-linked glycoproteomes and N- and O-glycomes, and their differential expression between T. cruzi strains and closely related trypanosome species. Taken together, this thesis shows the importance of proteomics in studying the molecular changes in protein expression and PTMs during host-pathogen interaction. Specifically, the methods developed and implemented in this thesis will be useful for the scientific community to study not only T. cruzi infections but also other biological systems. Finally, this thesis sheds new lights on the role of specific protein and PTMs targets for Chagas disease diagnostic and therapy