Insights into Transgenerational Epigenetics from Studies of Ciliates

Epigenetics, a term with many meanings, can be broadly defined as the study of dynamic states of the genome. Ciliates, a clade of unicellular eukaryotes, can teach us about the intersection of epigenetics and evolution due to the advantages of working with cultivable ciliate lineages, plus their tendency to express extreme phenotypes such as heritable doublet morphology. Moreover, ciliates provide a powerful model for studying epigenetics given the presence of dimorphic nuclei – a somatic macronucleus and germline micronucleus – within each cell. Here, we exemplify the power of studying ciliates to learn about epigenetic phenomena. We highlight “classical” examples from morphology and physiology including cortical inheritance, mating type determination, and serotype expression. In addition, we detail molecular studies of epigenetic phenomena, including: DNA elimination; alternative processing and unscrambling; and copy number determination. Based on the implications of these studies, we discuss epigenetics as a possible functional mechanism for rapid speciation in ciliates

Seed Bank and Seasonal Patterns of the Eukaryotic SAR (Stramenopila, Alveolata and Rhizaria) Clade in a New England Vernal Pool

Vernal pools are dynamic freshwater ecosystems that dry during the summer. These unique habitats are vital to a number of well-studied animal species but there is little documentation of the diversity of the SAR—Stramenopila, Alveolata and Rhizaria—clade in vernal pools. Here, we characterize the protist community over a portion of the hydroperiod as the vernal pool transitions from its winter stage through its drying out in late summer. Our study focuses on the SAR clade, which encompasses a broad range of morphological diversity and a variety of trophic modes within the microbial food web. Using high-throughput sequencing, we investigate the total community (DNA) and the active (RNA) members on a temporal scale. These molecular data reveal seasonality within microbial communities, suggesting a larger community of autotrophs in the winter followed by an increase in heterotrophs in the summer. Our analysis also suggests the presence of a microbial seed bank, a collection of encysted protists, in the sediments below the pool. We hypothesize the seed bank allows for community turnover: taxa encyst in the sediment in poor environmental conditions and exit their cysts when favorable conditions occur. We also observe seasonal preference and partitioning of the environment within clades of close relatives, including taxa closely related to the ciliate Halteria and the oomycete Haptoglossa. These data provide insights into the seasonal patterns of a frequently overlooked group of organisms in this unusual environment

The repeat structure of two paralogous genes, Yersinia ruckeri invasin (yrInv) and a "Y. ruckeri invasin-like molecule", (yrIlm) sheds light on the evolution of adhesive capacities of a fish pathogen

Inverse autotransporters comprise the recently identified type Ve secretion system and are exemplified by intimin from enterohaemorrhagic Escherichia coli and invasin from enteropathogenic Yersiniae. These proteins share a common domain architecture and promote bacterial adhesion to host cells. Here, we identified and characterized two putative inverse autotransporter genes in the fish pathogen Yersinia ruckeri NVH_3758, namely yrInv (for Y. ruckeri invasin) and yrIlm (for Y. ruckeri invasin-like molecule). When trying to clone the highly repetitive genes for structural and functional studies, we experienced problems in obtaining PCR products. PCR failures and the highly repetitive nature of inverse autotransporters prompted us to sequence the genome of Y. ruckeri NVH_3758 using PacBio sequencing, which produces some of the longest average read lengths available in the industry at this moment. According to our sequencing data, YrIlm is composed of 2603 amino acids (7812 bp) and has a molecular mass of 256.4 kDa. Based on the new genome information, we performed PCR analysis on four non-sequenced Y. ruckeri strains as well as the sequenced. Y. ruckeri type strain. We found that the genes are variably present in the strains, and that the length of yrIlm, when present, also varies. In addition, the length of the gene product for all strains, including the type strain, was much longer than expected based on deposited sequences. The internal repeats of the yrInv gene product are highly diverged, but represent the same bacterial immunoglobulin-like domains as in yrIlm. Using qRT-PCR, we found that yrIlm and yrInv are differentially expressed under conditions relevant for pathogenesis. In addition, we compared the genomic context of both genes in the newly sequenced Y. ruckeri strain to all available PacBio-sequenced Y. ruckeri genomes, and found indications of recent events of horizontal gene transfer. Taken together, this study demonstrates and highlights the power of Single Molecule Real-Time technology for sequencing highly repetitive proteins, and sheds light on the genetic events that gave rise to these highly repetitive genes in a commercially important fish pathogen

An evaluation of the prevalence of vancomycin-resistant enterococci (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) in hospital food

Los artículos que componen este libro ilustran desde múltiples puntos de vista el concepto de patrimonio biocultural. El contenido de la publicación se estructura en tres espacios sintetizados en las problemáticas asociadas al patrimonio biológico y cultural, el territorio y las disputas territoriales, la construcción identitaria y los problema de carácter socio-históricos de las comunidades afro indoamericanas. Ello permite, por un lado, obtener una aproximación contrastante, holística y compleja de la realidad latinoamericana y por otra lado sumar aportes a un concepto en construcción que no esconde su intencionalidad emancipadora.Agradecimientos; Introducción; PATRIMONIO BIOCULTURAL: Juan Pohlenz Córdova / La disputa por el patrimonio biocultural. Un acercamiento desde Mesoamérica; León Enrique Ávila Romero / La disputa por el patrimonio biocultural, la economía verde y sus impactos en los pueblos indígenas; Bernardo Javier Tobar / Lugares de vida y registros de la memoria biocultural en el Pacífico sur-colombiano; Iskra García Vázquez, Rocío Becerra Montané y Gimena Pérez Ortega / Uso, aprovechamiento social y conservación de las plantas medicinales en México; Kelly Giovanna Muñoz Balcázar / Transformaciones del territorio y el patrimonio biocultural a partir del proceso de industrialización. Recuperación de la finca tradicional en el municipio de Corinto, vereda La Paila; TERRITORIO: Johnny L. Ledezma Rivera / Reflexiones sobre las concepciones y visiones de lo que se entiende por territorio; Sindy Hernández Bonilla / ¿Justicia o legalidad para los q’eqchi’es? Agustín Ávila Romero / Turismo y pueblos indígenas de México: despojo y veredas de apropiación comunitaria; SOCIEDADES AFROINDOAMERICANAS EN MOVIMIENTO Johnny L. Ledezma Rivera / Construcción e implementación de las autonomías indígenas en Bolivia: avances y retrocesos; Stefano Claudio Sartorello / Educar para el arraigo sociocultural. El perfil de egreso de alumn@s indígenas en una propuesta educativa intercultural y bilingüe en Chiapas; Elena Pareja y Virginia Cornalino / La cultura afrodescendiente en la constitución del Estado-nación (1870-1900). La reconstrucción de los mapas de identidad en la frontera uruguayo-brasileña; Karla Chagas y Natalia Stalla / Mano de obra negra en el Estado Oriental: una mirada del trabajo esclavo y libre a través del análisis de casos; Diego E. Piñeiro y Joaquín Cardeillac / Los afro-descendientes en el campo uruguayo; Soledad Figueredo y Matías Carámbula Pareja / Puntos en el mapa: ensayo sobre identidad, inmovilidad y cultura de la población afrodescendiente en el medio rural uruguayo

Development of a biosensor for urea assay based on amidase inhibition, using an ion-selective electrode

A biosensor for urea has been developed based on the observation that urea is a powerful active-site inhibitor of amidase, which catalyzes the hydrolysis of amides such as acetamide to produce ammonia and the corresponding organic acid. Cell-free extract from Pseudomonas aeruginosa was the source of amidase (acylamide hydrolase, EC 3.5.1.4) which was immobilized on a polyethersulfone membrane in the presence of glutaraldehyde; anion-selective electrode for ammonium ions was used for biosensor development. Analysis of variance was used for optimization of the biosensorresponse and showed that 30 mu L of cell-free extract containing 7.47 mg protein mL(-1), 2 mu L of glutaraldehyde (5%, v/v) and 10 mu L of gelatin (15%, w/v) exhibited the highest response. Optimization of other parameters showed that pH 7.2 and 30 min incubation time were optimum for incubation ofmembranes in urea. The biosensor exhibited a linear response in the range of 4.0-10.0 mu M urea, a detection limit of 2.0 mu M for urea, a response timeof 20 s, a sensitivity of 58.245 % per mu M urea and a storage stability of over 4 months. It was successfully used for quantification of urea in samples such as wine and milk; recovery experiments were carried out which revealed an average substrate recovery of 94.9%. The urea analogs hydroxyurea, methylurea and thiourea inhibited amidase activity by about 90%, 10% and 0%, respectively, compared with urea inhibition

Revista de Ciencias Sociales (Vol. 27 no. 34 ene-jun 2014)

Políticas públicas y representaciones sociales/ Verónica Filardo Problemas de integridad en programas de tratamiento. El caso del Centro Nacional de Rehabilitación/ Emiliano Rojido, Ana Vigna y Nicolás Trajtenberg ¿Por qué los adolescentes no son el problema de la delincuencia uruguaya? Análisis comparativo en doble sentido: infracción-delito y Uruguay-México/ Gabriel Tenenbaum Ewig Población rural en Uruguay. Aportes para su reconceptualización/ Diego E. Piñeiro y Joaquín Cardeillac Discurso experto en el cuidado de personas mayores. Un análisis de género/ Karina Batthyány, Natalia Genta y Valentina Perrotta Percepciones de desigualdad socioeconómica. Un estudio exploratorio para el caso argentino/ Santiago Andrés Rodríguez Reseñas bibliográficas Ciencias Sociales en América Latina: de los inicios de la Sociología a la teoría de la dependencia, Hélgio Trindade(coord.)/Gerónimo de Sierra y Gabriel E. Vitullo. Por Alberto Riella Regionalización cultural del Uruguay,Felipe Arocena (comp.)Por Mónica Olaz

Effects of MASP-1 of the Complement System on Activation of Coagulation Factors and Plasma Clot Formation

BACKGROUND: Numerous interactions between the coagulation and complement systems have been shown. Recently, links between coagulation and mannan-binding lectin-associated serine protease-1 (MASP-1) of the complement lectin pathway have been proposed. Our aim was to investigate MASP-1 activation of factor XIII (FXIII), fibrinogen, prothrombin, and thrombin-activatable fibrinolysis inhibitor (TAFI) in plasma-based systems, and to analyse effects of MASP-1 on plasma clot formation, structure and lysis. METHODOLOGY/PRINCIPAL FINDINGS: We used a FXIII incorporation assay and specific assays to measure the activation products prothrombin fragment F1+2, fibrinopeptide A (FPA), and activated TAFI (TAFIa). Clot formation and lysis were assessed by turbidimetric assay. Clot structure was studied by scanning electron microscopy. MASP-1 activated FXIII and, contrary to thrombin, induced FXIII activity faster in the Val34 than the Leu34 variant. MASP-1-dependent generation of F1+2, FPA and TAFIa showed a dose-dependent response in normal citrated plasma (NCP), albeit MASP-1 was much less efficient than FXa or thrombin. MASP-1 activation of prothrombin and TAFI cleavage were confirmed in purified systems. No FPA generation was observed in prothrombin-depleted plasma. MASP-1 induced clot formation in NCP, affected clot structure, and prolonged clot lysis. CONCLUSIONS/SIGNIFICANCE: We show that MASP-1 interacts with plasma clot formation on different levels and influences fibrin structure. Although MASP-1-induced fibrin formation is thrombin-dependent, MASP-1 directly activates prothrombin, FXIII and TAFI. We suggest that MASP-1, in concerted action with other complement and coagulation proteins, may play a role in fibrin clot formation

Cleavage of Kininogen and Subsequent Bradykinin Release by the Complement Component: Mannose-Binding Lectin-Associated Serine Protease (MASP)-1

Bradykinin (BK), generated from high-molecular-weight kininogen (HK) is the major mediator of swelling attacks in hereditary angioedema (HAE), a disease associated with C1-inhibitor deficiency. Plasma kallikrein, activated by factor XIIa, is responsible for most of HK cleavage. However other proteases, which activate during episodes of angioedema, might also contribute to BK production. The lectin pathway of the complement system activates after infection and oxidative stress on endothelial cells generating active serine proteases: MASP-1 and MASP-2. Our aim was to study whether activated MASPs are able to digest HK to release BK. Initially we were trying to find potential new substrates of MASP-1 in human plasma by differential gel electrophoresis, and we identified kininogen cleavage products by this proteomic approach. As a control, MASP-2 was included in the study in addition to MASP-1 and kallikrein. The proteolytic cleavage of HK by MASPs was followed by SDS-PAGE, and BK release was detected by HPLC. We showed that MASP-1 was able to cleave HK resulting in BK production. MASP-2 could also cleave HK but could not release BK. The cleavage pattern of MASPs is similar but not strictly identical to that of kallikrein. The catalytic efficiency of HK cleavage by a recombinant version of MASP-1 and MASP-2 was about 4.0×102 and 2.7×102 M−1s−1, respectively. C1-inhibitor, the major inhibitor of factor XIIa and kallikrein, also prevented the cleavage of HK by MASPs. In all, a new factor XII- and kallikrein-independent mechanism of bradykinin production by MASP-1 was demonstrated, which may contribute to the pro-inflammatory effect of the lectin pathway of complement and to the elevated bradykinin levels in HAE patients

The Role of Humoral Innate Immunity in Hepatitis C Virus Infection

Infection with Hepatitis C Virus (HCV) causes chronic disease in approximately 80% of cases, resulting in chronic inflammation and cirrhosis. Current treatments are not completely effective, and a vaccine has yet to be developed. Spontaneous resolution of infection is associated with effective host adaptive immunity to HCV, including production of both HCV-specific T cells and neutralizing antibodies. However, the supporting role of soluble innate factors in protection against HCV is less well understood. The innate immune system provides an immediate line of defense against infections, triggering inflammation and playing a critical role in activating adaptive immunity. Innate immunity comprises both cellular and humoral components, the humoral arm consisting of pattern recognition molecules such as complement C1q, collectins and ficolins. These molecules activate the complement cascade, neutralize pathogens, and recruit antigen presenting cells. Here we review the current understanding of anti-viral components of the humoral innate immune system that play a similar role to antibodies, describing their role in immunity to HCV and their potential contribution to HCV pathogenesis