220 research outputs found
Enfermedad y daño. Etiología y tratamiento de la viruela entre las sociedades nativas de Araucanía (fines del siglo XVIII)
In the year of 1791, a smallpox epidemic which affected the Indian populations of the Arauco frontier –south of Bío-Bío river in Chile– worried the colonial authorities of Concepción, due to the fear that the Spanish inhabitants of that region could also get infected. Acting according to the contagion paradigm, they imposed a cordon sanitaire in order to isolate them from the Natives, and suggested these do the same. Also, conscious that the plague was commonly attributed to Spanish witchcraft, they hurried to offer medicine and medical advice, in order to show there was no will to cause damage. The responses of the different Indian groups demonstrated the co-existence of a wide variety of perspectives regarding the etiology of smallpox and the possible paths of action: from a personalist conception which attributed it to witches’ activities, to the admission of their own inability to find proper treatment, which led to the acceptance of Spanish medicines. The general picture shows a native model of the illness that is both conservative and innovative, complex and dynamic at the same time. The description of those events, found in a folder which was later sent to Spain, and the references contained in other colonial documents, allow the examination of the epidemiologic event using as a comparative context the conceptualizations now current among the Mapuche. They also allow the analysis of dominant conceptions concerning illness among the Spaniards in the late eighteenth century.En el año 1791, una epidemia de viruelas que afectaba a las poblaciones indígenas de la frontera de Arauco –situadas al sur del río Bío-Bío en Chile– se constituyó en seria preocupación para las autoridades coloniales de Concepción, debido al temor de que los habitantes hispano-criollos de la región pudieran verse infestados. Actuando de acuerdo con el paradigma del contagio, impusieron un cordón sanitario que los aislara de los nativos y sugirieron a éstos que hicieran otro tanto. Conscientes además de que la peste era atribuida a la hechicería hispana, se apresuraron a ofrecer remedios y asesoramiento médico, con la finalidad de demostrar que no mediaba voluntad de provocar daño. Las respuestas de las distintas agrupaciones evidenciaron la coexistencia de una variedad de perspectivas con respecto a la etiología de la viruela y a los posibles cursos de acción: desde una concepción personalista que la atribuía a la actividad de los brujos, hasta una llana admisión de la propia incapacidad para tratarla que derivaba en la aceptación de las medicinas españolas. El cuadro general muestra un modelo nativo de la enfermedad, a la vez conservador e innovador, complejo y dinámico. La descripción de los eventos en un expediente que luego se envió a España y las referencias contenidas en otras fuentes coloniales permiten el examen del episodio epidemiológico utilizando como contexto comparativo las conceptualizaciones actualmente vigentes entre los mapuche, pero también el análisis de las concepciones dominantes al respecto entre los propios españoles a fines del siglo XVIII
Close similarities between Cherry chlorotic rusty spot disease from Italy and Cherry leaf scorch from Spain
Cherry chlorotic rusty spot (CCRS), a disease affecting sweet and sour cherry in Southern Italy was regularly found associated with an unidentified fungus and with a complex pattern of viral-like double-stranded RNAs as well as with two small circular RNAs (cherry small circular RNAs, cscRNAs). Further studies revealed that i) the ds-RNAs correspond to the genome of different mycoviruses belonging to the genera Chrysovirus, Partitivirus and Totivirus and ii) the two viroid-like RNAs consist of two groups of variants with similar sequences but differing in size (394–415 and 372–377 nt for cscRNA1 and cscRNA2, respectively). Here we report that the dsRNAs of Chrysovirus and Partitivirus have been detected by RT-PCR analysis with CCRS specific primers in nucleic acid preparations from cherry leaves affected by cherry leaf scorch (CLS) in Spain, a disease whose etiological agent is the ascomycetes Apiognomonia erythrostoma, order Diaporthales. Moreover, Northern-blot hybridization assays showed that a viroid-like RNA comigrating and sharing high sequence similarity with the cscRNA1 previously reported in Italy, accumulate in leaves from CLS affected trees in Spain. These data, together with other evidence showing similar symptoms, disease cycle and fungal fructifications in CCRS and CLS affected trees, suggest a close relationship between the two cherry disorders.Keywords: dsRNAs, cscRNAs, Apiognomonia erythrostoma, Diaporthale
Genomic Organization and Evolution of the Vomeronasal Type 2 Receptor-Like (OlfC) Gene Clusters in Atlantic Salmon, Salmo salar
There are three major multigene superfamilies of olfactory receptors (OR, V1R, and V2R) in mammals. The ORs are expressed in the main olfactory organ, whereas the V1Rs and V2Rs are located in the vomeronasal organ. Fish only possess one olfactory organ in each nasal cavity, the olfactory rosette; therefore, it has been proposed that their V2R-like genes be classified as olfactory C family G protein-coupled receptors (OlfC). There are large variations in the sizes of OR gene repertoires. Previous studies have shown that fish have between 12 and 46 functional V2R-like genes, whereas humans have lost all functional V2Rs, and frog sp. have more than 240. Pseudogenization of V2R genes is a prevalent event across species. In the mouse and frog genomes, there are approximately double the number of pseudogenes compared with functional genes. An oligonucleotide probe was designed from a conserved sequence from four Atlantic salmon OlfC genes and used to screen the Atlantic salmon bacterial artificial chromosome (BAC) library. Hybridization-positive BACs were matched to fingerprint contigs, and representative BACs were shotgun cloned and sequenced. We identified 55 OlfC genes. Twenty-nine of the OlfC genes are classified as putatively functional genes and 26 as pseudogenes. The OlfC genes are found in two genomic clusters on chromosomes 9 and 20. Phylogenetic analysis revealed that the OlfC genes could be divided into 10 subfamilies, with nine of these subfamilies corresponding to subfamilies found in other teleosts and one being salmon specific. There is also a large expansion in the number of OlfC genes in one subfamily in Atlantic salmon. Subfamily gene expansions have been identified in other teleosts, and these differences in gene number reflect species-specific evolutionary requirements for olfaction. Total RNA was isolated from the olfactory epithelium and other tissues from a presmolt to examine the expression of the odorant genes. Several of the putative OlfC genes that we identified are expressed only in the olfactory epithelium, consistent with these genes encoding odorant receptors
Rapid production of pure recombinant actin isoforms in Pichia pastoris
Actins are major eukaryotic cytoskeletal proteins, which perform many important cell functions, including cell division, cell polarity, wound healing, and muscle contraction. Despite obvious drawbacks, muscle actin, which is easily purified, is used extensively presently for biochemical studies of actin cytoskeleton from other organisms / cell types. Here we report a rapid and cost-effective method to purify heterologous actins expressed in the yeast Pichia pastoris. Actin is expressed as a fusion with the actin-binding protein thymosin β4 and purified using an affinity tag introduced in the fusion. Following cleavage of thymosin β4 and the affinity tag, highly purified functional full-length actin is liberated. We purify actins from S. cerevisiae, S. pombe, and the β- and γ- isoforms of human actin. We also report a modification of the method that facilitates expression and purification of arginylated actin, a form of actin thought to regulate actin dendritic networks in mammalian cells. The methods we describe can be performed in all laboratories equipped for molecular biology, and should greatly facilitate biochemical and cell biological studies of the actin cytoskeleton
Expression of Odorant Receptor Family, Type 2 OR in the Aquatic Olfactory Cavity of Amphibian Frog Xenopus tropicalis
Recent genome wide in silico analyses discovered a new family (type 2 or family H) of odorant receptors (ORs) in teleost fish and frogs. However, since there is no evidence of the expression of these novel OR genes in olfactory sensory neurons (OSN), it remains unknown if type 2 ORs (OR2) function as odorant receptors. In this study, we examined expression of OR2 genes in the frog Xenopus tropicalis. The overall gene expression pattern is highly complex and differs depending on the gene and developmental stage. RT-PCR analysis in larvae showed that all of the OR2η genes we identified were expressed in the peripheral olfactory system and some were detected in the brain and skin. Whole mount in situ hybridization of the larval olfactory cavity confirmed that at least two OR2η genes so far tested are expressed in the OSN. Because tadpoles are aquatic animals, OR2η genes are probably involved in aquatic olfaction. In adults, OR2η genes are expressed in the nose, brain, and testes to different degrees depending on the genes. OR2η expression in the olfactory system is restricted to the medium cavity, which participates in the detection of water-soluble odorants, suggesting that OR2ηs function as receptors for water-soluble odorants. Moreover, the fact that several OR2ηs are significantly expressed in non-olfactory organs suggests unknown roles in a range of biological processes other than putative odorant receptor functions
Transposons played a major role in the diversification between the closely related almond and peach genomes: Results from the almond genome sequence
We sequenced the genome of the highly heterozygous almond Prunus dulcis cv. Texas combining short and long‐read sequencing. We obtained a genome assembly totaling 227.6 Mb of the estimated 238 Mb almond genome size, of which 91% is anchored to eight pseudomolecules corresponding to its haploid chromosome complement, and annotated 27,969 protein‐coding genes and 6,747 non‐coding transcripts. By phylogenomic comparison with the genomes of 16 additional close and distant species we estimated that almond and peach (P. persica) diverged around 5.88 Mya. These two genomes are highly syntenic and show a high degree of sequence conservation (20 nucleotide substitutions/kb). However, they also exhibit a high number of presence/absence variants, many attributable to the movement of transposable elements (TEs). TEs have generated an important number of presence/absence variants between almond and peach, and we show that the recent history of TE movement seems markedly different between them. TEs may also be at the origin of important phenotypic differences between both species, and in particular, for the sweet kernel phenotype, a key agronomic and domestication character for almond. Here we show that in sweet almond cultivars, highly methylated TE insertions surround a gene involved in the biosynthesis of amygdalin, whose reduced expression has been correlated with the sweet almond phenotype. Altogether, our results suggest a key role of TEs in the recent history and diversification of almond and its close relative peach.info:eu-repo/semantics/publishedVersio
A chromosome-level genome assembly enables the identification of the follicule stimulating hormone receptor as the master sex determining gene in the flatfish Solea senegalensis
Sex determination (SD) shows huge variation among fish and a high evolutionary rate, as illustrated by the Pleuronectiformes (flatfishes). This order is characterized by its adaptation to demersal life, compact genomes and diversity of SD mechanisms. Here, we assembled the Solea senegalensis genome, a flatfish of great commercial value, into 82 contigs (614 Mb) combining long- and short-read sequencing, which were next scaffolded using a highly dense genetic map (28,838 markers, 21 linkage groups), representing 98.9% of the assembly. Further, we established the correspondence between the assembly and the 21 chromosomes by using BAC-FISH. Whole genome resequencing of six males and six females enabled the identification of 41 SNP variants in the follicle stimulating hormone receptor (fshr) consistent with an XX / XY SD system. The observed sex association was validated in a broader independent sample, providing a novel molecular sexing tool. Fshr displayed differential gene expression between male and female gonads from 86 days post-fertilization, when the gonad is still an undifferentiated primordium, concomitant with the activation of amh and cyp19a1a, testis and ovary marker genes, respectively, in males and females. The Y-linked fshr allele, which included 24 non-synonymous variants and showed a highly divergent 3D protein structure, was overexpressed in males compared to the X-linked allele at all stages of gonadal differentiation. We hypothesize a mechanism hampering the action of the follicle stimulating hormone driving the undifferentiated gonad toward testis.info:eu-repo/semantics/acceptedVersio
Intersect-then-combine approach: improving the performance of somatic variant calling in whole exome sequencing data using multiple aligners and callers
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