Myocardial-specific R-spondin3 drives proliferation of the coronary stems primarily through the Leucine Rich Repeat G Protein coupled receptor LGR4

Coronary artery anomalies are common congenital disorders with serious consequences in adult life. Coronary circulation begins when the coronary stems form connections between the aorta and the developing vascular plexus. We recently identified the WNT signaling modulator R-spondin 3 (Rspo3), as a crucial regulator of coronary stem proliferation. Using expression analysis and tissue-specific deletion we now demonstrate that Rspo3 is primarily produced by cardiomyocytes. Moreover, we have employed CRISPR/Cas9 technology to generate novel Lgr4-null alleles that showed a significant decrease in coronary stem proliferation and thus phenocopied the coronary artery defects seen in Rspo3 mutants. Interestingly, Lgr4 mutants displayed slightly hypomorphic right ventricles, an observation also made after myocardial specific deletion of Rspo3. These results shed new light on the role of Rspo3 in heart development and demonstrate that LGR4 is the principal Rspondin 3 receptor in the heart

A Plasmodium falciparum FcB1-schizont-EST collection providing clues to schizont specific gene structure and polymorphism

<p>Abstract</p> <p>Background</p> <p>The <it>Plasmodium falciparum </it>genome (3D7 strain) published in 2002, revealed ~5,400 genes, mostly based on <it>in silico </it>predictions. Experimental data is therefore required for structural and functional assessments of <it>P. falciparum </it>genes and expression, and polymorphic data are further necessary to exploit genomic information to further qualify therapeutic target candidates. Here, we undertook a large scale analysis of a <it>P. falciparum </it>FcB1-schizont-EST library previously constructed by suppression subtractive hybridization (SSH) to study genes expressed during merozoite morphogenesis, with the aim of: 1) obtaining an exhaustive collection of schizont specific ESTs, 2) experimentally validating or correcting <it>P. falciparum </it>gene models and 3) pinpointing genes displaying protein polymorphism between the FcB1 and 3D7 strains.</p> <p>Results</p> <p>A total of 22,125 clones randomly picked from the SSH library were sequenced, yielding 21,805 usable ESTs that were then clustered on the <it>P. falciparum </it>genome. This allowed identification of 243 protein coding genes, including 121 previously annotated as hypothetical. Statistical analysis of GO terms, when available, indicated significant enrichment in genes involved in "entry into host-cells" and "actin cytoskeleton". Although most ESTs do not span full-length gene reading frames, detailed sequence comparison of FcB1-ESTs versus 3D7 genomic sequences allowed the confirmation of exon/intron boundaries in 29 genes, the detection of new boundaries in 14 genes and identification of protein polymorphism for 21 genes. In addition, a large number of non-protein coding ESTs were identified, mainly matching with the two A-type rRNA units (on chromosomes 5 and 7) and to a lower extent, two atypical rRNA loci (on chromosomes 1 and 8), TARE subtelomeric regions (several chromosomes) and the recently described telomerase RNA gene (chromosome 9).</p> <p>Conclusion</p> <p>This FcB1-schizont-EST analysis confirmed the actual expression of 243 protein coding genes, allowing the correction of structural annotations for a quarter of these sequences. In addition, this analysis demonstrated the actual transcription of several remarkable non-protein coding loci: 2 atypical rRNA, TARE region and telomerase RNA gene. Together with other collections of <it>P. falciparum </it>ESTs, usually generated from mixed parasite stages, this collection of FcB1-schizont-ESTs provides valuable data to gain further insight into the <it>P. falciparum </it>gene structure, polymorphism and expression.</p

Indicador general de calidad del suelo en diferentes sistemas de uso del suelo en el Sur de Brasil

Como la degradación de los ecosistemas está asociada con una pérdida importante de la biodiversidad del suelo, es necesario evaluar la calidad del mismo para identificar y desarrollar prácticas agrícolas sustentables. Velasquez et al. (2007) propusieron un Indicador General de la Calidad del Suelo (GISQ en inglés) que combina varios subindicadores. Estos también pueden ser considerados para la evaluación de varios servicios ecosistémicos (SE) como la biodiversidad, la estructura del suelo, la reserva hídrica y el ciclo de los nutrientes. El objetivo del trabajo fue evaluar el impacto de diferentes usos del suelo en una Reserva Natural en Brasil sobre la calidad del suelo. En cada sistema se midieron las variables asociadas a la diversidad del suelo, fertilidad, propiedades físicas y morfología de los agregados. En el bosque se obtuvieron los mayores valores para el GISQ (0,80) y para los subindicadores de macrofauna, química y física. El análisis ACP diferenció significativamente (p<0.001) el cultivo de Soja de los otros sistemas, basado en sus valores menores en los subindicadores. El GISQ reflejó la provisión de los SE, mostrando que a mayor calidad del suelo, mayor es la producción de SE. La metodología utilizada puede ser aplicada en cualquier lugar y permite el monitoreo de los cambios de usos de suelo. Además, podría ayudar en la implementación de tecnologías de restauración del suelo.Since the degradation of ecosystems is associated with an important loss of soil biodiversity, there is an urgent need for soil quality evaluation in order to identify and develop more sustainable practices. A General Indicator of Soil Quality (GISQ) has been proposed by Velasquez et al. (2007) which combines a set of subindicators. These subindicators may also be considered as indicators of the performance of different ecosystem services (ES) such as soil structure and nutrient cycling. This study aimed to evaluate the impact of different landuse systems on soil quality in a Natural Reserve of South Brazil. Variables associated with soil biodiversity, fertility, physical properties and aggregate morphology were measured for each system. The highest GISQ average value was calculated for the Forest (0.80), while this system also had the highest values for macrofauna, chemical and physical subindicators. PCA analysis showed a significant separation (p<0.001) of the Soybean crop from the others systems based on the lowest subindicators values. The GISQ reflected the provision of soil ES, showing that better soil quality produces more ES. The methodology used can be applied extensively and allows monitoring of land-use changes through time. It could therefore guide the implementation of soil restoration technologies.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Indicador general de calidad del suelo en diferentes sistemas de uso del suelo en el Sur de Brasil

Como la degradación de los ecosistemas está asociada con una pérdida importante de la biodiversidad del suelo, es necesario evaluar la calidad del mismo para identificar y desarrollar prácticas agrícolas sustentables. Velasquez et al. (2007) propusieron un Indicador General de la Calidad del Suelo (GISQ en inglés) que combina varios subindicadores. Estos también pueden ser considerados para la evaluación de varios servicios ecosistémicos (SE) como la biodiversidad, la estructura del suelo, la reserva hídrica y el ciclo de los nutrientes. El objetivo del trabajo fue evaluar el impacto de diferentes usos del suelo en una Reserva Natural en Brasil sobre la calidad del suelo. En cada sistema se midieron las variables asociadas a la diversidad del suelo, fertilidad, propiedades físicas y morfología de los agregados. En el bosque se obtuvieron los mayores valores para el GISQ (0,80) y para los subindicadores de macrofauna, química y física. El análisis ACP diferenció significativamente (p<0.001) el cultivo de Soja de los otros sistemas, basado en sus valores menores en los subindicadores. El GISQ reflejó la provisión de los SE, mostrando que a mayor calidad del suelo, mayor es la producción de SE. La metodología utilizada puede ser aplicada en cualquier lugar y permite el monitoreo de los cambios de usos de suelo. Además, podría ayudar en la implementación de tecnologías de restauración del suelo.Since the degradation of ecosystems is associated with an important loss of soil biodiversity, there is an urgent need for soil quality evaluation in order to identify and develop more sustainable practices. A General Indicator of Soil Quality (GISQ) has been proposed by Velasquez et al. (2007) which combines a set of subindicators. These subindicators may also be considered as indicators of the performance of different ecosystem services (ES) such as soil structure and nutrient cycling. This study aimed to evaluate the impact of different landuse systems on soil quality in a Natural Reserve of South Brazil. Variables associated with soil biodiversity, fertility, physical properties and aggregate morphology were measured for each system. The highest GISQ average value was calculated for the Forest (0.80), while this system also had the highest values for macrofauna, chemical and physical subindicators. PCA analysis showed a significant separation (p<0.001) of the Soybean crop from the others systems based on the lowest subindicators values. The GISQ reflected the provision of soil ES, showing that better soil quality produces more ES. The methodology used can be applied extensively and allows monitoring of land-use changes through time. It could therefore guide the implementation of soil restoration technologies.Eje A4: Ambiente, Naturaleza y AgroecologíaFacultad de Ciencias Agrarias y Forestale

Recomendações para avaliação de populações de minhocas em ecossistemas brasileiros

Earthworms are often related to fertile soils and are also frequently used as environmental quality indicators. However, to optimize their use as bioindicators, earthworm populations must be evaluated together with the environmental and anthropogenic variables regulating their communities. This review sought to identify the earthworm-sampling, soil chemical and physical, and environmental and anthropogenic attributes evaluated in 124 published studies that quantified earthworm abundance (>7,300 samples) in 765 sites with different types of climate, soils, land use, and management systems in Brazil. Soil chemical and physical attributes (except pH) were less reported (≤50% of studies) than other environmental variables such as sampling date, altitude, temperature, precipitation, climate and soil type, and land use (>50% of studies). Earthworms were rarely identified (24%) and few studies (31%) measured their biomass, although most provided adequate information on sampling protocol. Based on their importance in regulating earthworm populations, a set of variables is proposed to be evaluated when studying earthworm communities and other macrofauna groups. This should help guide future studies on earthworms in Brazil and other countries, optimize data collection and replicability, allow comparisons between different studies, and promote the use of earthworms as soil quality bioindicators.As minhocas são frequentemente relacionadas a solos férteis e, também, bastante usadas como indicadores da qualidade ambiental. No entanto, para otimizar seu uso como bioindicadores, as populações de minhocas devem ser avaliadas juntamente com as variáveis ambientais e antropogênicas que regulam as suas comunidades. Esta revisão buscou identificar os atributos relacionados à amostragem de minhocas, físicos e químicos dos solos, e ambientais e antropogênicos avaliados em 124 estudos publicados que quantificaram a abundância de minhocas (>7.300 amostras) em 765 locais com diferentes tipos de clima, solos, uso da terra e sistemas de manejo no Brasil. Os atributos químicos e físicos do solo (exceto pH) foram menos relatados (≤50% dos estudos) do que outras variáveis ambientais, como data de coleta, altitude, temperatura, precipitação, tipo de solo e de clima, e uso do solo (>50% dos estudos). As minhocas foram raramente identificadas (24%) e poucos estudos (31%) mediram sua biomassa, embora a maioria tenha fornecido informações adequadas sobre o protocolo de amostragem. Com base na sua importância para a regulação das populações de minhocas, propõe-se um conjunto de variáveis que devem ser avaliadas no estudo de comunidades de minhocas e outros grupos da macrofauna do solo. Isso deve ajudar a guiar futuros estudos sobre minhocas no Brasil e em outros países, otimizar a coleta e a replicabilidade de dados, permitir comparações entre diferentes estudos e promover o uso de minhocas como bioindicadores da qualidade do solo

Comparative Gene Expression Analysis throughout the Life Cycle of Leishmania braziliensis: Diversity of Expression Profiles among Clinical Isolates

Leishmania is a group of parasites (Protozoa, Trypanosomatidae) responsible for a wide spectrum of clinical forms. Among the factors explaining this phenotypic polymorphism, parasite features are important contributors. One approach to identify them consists in characterizing the gene expression profiles throughout the life cycle. In a recent study, the transcriptome of 3 Leishmania species was compared and this revealed species-specific differences, albeit in a low number. A key issue, however, is to ensure that the observed differences are indeed species-specific and not specific of the strains selected for representing the species. In order to illustrate the relevance of this concern, we analyzed here the gene expression profiles of 5 clinical isolates of L. braziliensis at seven time points of the life cycle. Our results clearly illustrate the unique character of each isolate in terms of gene expression dynamics: one Leishmania strain is not necessarily representative of a given species

A“Dirty” Footprint: Macroinvertebrate diversity in Amazonian Anthropic Soils

International audienceAmazonian rainforests, once thought to be pristine wilderness, are increasingly known to have been widely inhabited, modified, and managed prior to European arrival, by human populations with diverse cultural backgrounds. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by pre-Columbian societies with sedentary habits. Much is known about the chemistry of these soils, yet their zoology has been neglected. Hence, we characterized soil fertility, macroinvertebrate communities, and their activity at nine archeological sites in three Amazonian regions in ADEs and adjacent reference soils under native forest (young and old) and agricultural systems. We found 673 morphospecies and, despite similar richness in ADEs (385 spp.) and reference soils (399 spp.), we identified a tenacious pre-Columbian footprint, with 49% of morphospecies found exclusively in ADEs. Termite and total macroinvertebrate abundance were higher in reference soils, while soil fertility and macroinvertebrate activity were higher in the ADEs, and associated with larger earthworm quantities and biomass. We show that ADE habitats have a unique pool of species, but that modern land use of ADEs decreases their populations, diversity, and contributions to soil functioning. These findings support the idea that humans created and sustained high-fertility ecosystems that persist today, altering biodiversity patterns in Amazonia