25 research outputs found
Nuevos registros de Moluchia strigata (Blanchard, 1851) (Blattodea: Ectobiidae) en el Matorral MediterrĂĄneo de Chile Central
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The Helicobacter pylori Genome Project : insights into H. pylori population structure from analysis of a worldwide collection of complete genomes
Helicobacter pylori, a dominant member of the gastric microbiota, shares co-evolutionary history with humans. This has led to the development of genetically distinct H. pylori subpopulations associated with the geographic origin of the host and with differential gastric disease risk. Here, we provide insights into H. pylori population structure as a part of the Helicobacter pylori Genome Project (HpGP), a multi-disciplinary initiative aimed at elucidating H. pylori pathogenesis and identifying new therapeutic targets. We collected 1011 well-characterized clinical strains from 50 countries and generated high-quality genome sequences. We analysed core genome diversity and population structure of the HpGP dataset and 255 worldwide reference genomes to outline the ancestral contribution to Eurasian, African, and American populations. We found evidence of substantial contribution of population hpNorthAsia and subpopulation hspUral in Northern European H. pylori. The genomes of H. pylori isolated from northern and southern Indigenous Americans differed in that bacteria isolated in northern Indigenous communities were more similar to North Asian H. pylori while the southern had higher relatedness to hpEastAsia. Notably, we also found a highly clonal yet geographically dispersed North American subpopulation, which is negative for the cag pathogenicity island, and present in 7% of sequenced US genomes. We expect the HpGP dataset and the corresponding strains to become a major asset for H. pylori genomics
New records of Moluchia strigata (Blanchard, 1851) (Blattodea: Ectobiidae) in Mediterranean Matorral, Central Chile
A new genus and species of Lasiopteridi (Diptera, Cecidomyiidae) on Haplopappus foliosus (Asteraceae) from Chile
A new genus and species of gall midge, Haplopappusmyia gregaria, is described and illustrated (larva, pupa, male, and female). This species induces apical galls on Haplopappus foliosus (Asteraceae), an endemic shrub from central Chile. The specimens were collected at La Ligua Municipality, Petorca Province, Valparaiso region, Chile, during spring of 2011â2014. This area corresponds to one of the fifth Mediterranean Matorral biome, considered among Earth's biodiversity hotspots. The new genus is characterized by presenting lateral margin of antennal scape with a mesal reentrance; four-segmented palpus, one-toothed tarsal claws, R5 straight, reaching C anterior to wing apex; male seventh and eighth tergites lacking sclerotization mesally, beyond proximal margin; presence of trichoid sensilla on the abdominal terga and sterna of both sexes, protrusible ovipositor with elongate fused cerci, and larva with 4 pairs of setose terminal papillae. Keywords: Gall midge, Morphology, Neotropical, Taxonom
The Importance of ncRNAs as Epigenetic Mechanisms in Phenotypic Variation and Organic Evolution
Neo-Darwinian explanations of organic evolution have settled on mutation as the principal factor in producing evolutionary novelty. Mechanistic characterizations have been also biased by the classic dogma of molecular biology, where only proteins regulate gene expression. This together with the rearrangement of genetic information, in terms of genes and chromosomes, was considered the cornerstone of evolution at the level of natural populations. This predominant view excluded both alternative explanations and phenomenologies that did not fit its paradigm. With the discovery of non-coding RNAs (ncRNAs) and their role in the control of genetic expression, new mechanisms arose providing heuristic power to complementary explanations to evolutionary processes overwhelmed by mainstream genocentric views. Viruses, epimutation, paramutation, splicing, and RNA editing have been revealed as paramount functions in genetic variations, phenotypic plasticity, and diversity. This article discusses how current epigenetic advances on ncRNAs have changed the vision of the mechanisms that generate variation, how organism-environment interaction can no longer be underestimated as a driver of organic evolution, and how it is now part of the transgenerational inheritance and evolution of species
The effect of larval and early adult experience on behavioural plasticity of the aphid parasitoid Aphidius ervi (Hymenoptera, Braconidae, Aphidiinae)
Abstract The relevance of the integration of preimaginal and eclosion experiences on the subsequent habitat preferences and mate finding by the adult has been rarely tested in holometabolous insects. In this work, the effect of larval and early adult experiences on the behavioural responses of adult males of the aphid parasitoid, Aphidius ervi, towards volatiles from the host-plant complex (HPC) and from conspecific females were evaluated. Two experience factors were considered: host diet (normal diet = ND; artificial diet = AD), and eclosion, i.e. extraction or non-extraction of the parasitoid larva from the parasitised aphid (extracted = EX; non-extracted = NE). Thus, four treatments were set up: ND/NE, ND/EX, AD/NE and AD/EX. Glass Y-tube olfactometers were used to investigate the responses of adult A. ervi males to the odour sources used. Males from the ND/NE treatment showed a shorter latency to the first choice of olfactometer arms, displayed a marked preference towards the HPC olfactometer arm, and spent more time in the HPC arm than males from the other treatments. Only the interaction of host diet and eclosion experiences proved to be relevant in explaining the differences in latency to first choice, time spent in olfactometers arms, and behaviours displayed in the olfactometer arms. These results show the importance of the integration of larval and eclosion experiences in the development of stereotyped responses of the adults. This process may involve memory retention from the preimaginal and emergence period, but further research is needed to disentangle the contribution of each stage. The response to conspecific females was much less affected by the treatments in relation to first arm choice and times in olfactometer arms, suggesting a pheromonemediated behaviour, even though a prompter and more intense wing fanning courtship behaviour was registered in the ND/NE males compared to males from the AD/NE treatment. These results show that sexual behaviours are less affected by early experiences than behaviours related with finding a HPC for foraging or oviposition. Taken together, our results demonstrate for first time that larval and eclosion experiences affect in a differential way the early responses of the adult towards environment-derived cues and mate related cues
Differences in arthropods found in flowers versus trapped in plant resins on Haplopappus platylepis Phil. (Asteraceae): Can the plant discriminate between pollinators and herbivores?
© 2014, Springer Science+Business Media Dordrecht. Plants produce secondary metabolites related to ecologically relevant processes. These compounds include surface secretions such as latex, mucilage and resins that help plants face abiotic and biotic environmental threats such as drought, nutrient deficiency, extreme temperatures and UV radiation, as well as herbivory, pathogenic microorganisms and other natural enemies. We studied the resinous coating found on involucral bracts of Haplopappus platylepis Phil. (Asteraceae). This plant belongs to a speciose genus widely distributed in South America (Lane and Hartman in Am J Bot 83:356, 1996). H.platylepis is characterized by resinous fragrant leaves. In this species, resins cover the involucral bracts as well as young leaves and are also secreted on reproductive stalks in smaller amounts. We carried out chemical analysis and natural history observations in order to identify whether arthropods caught in inflorescence resin differed fro
The effect of larval and early adult experience on behavioural plasticity of the aphid parasitoid Aphidius ervi (Hymenoptera, Braconidae, Aphidiinae)
The relevance of the integration of preimaginal and eclosion experiences on the subsequent habitat preferences and mate finding by the adult has been rarely tested in holometabolous insects. In this work, the effect of larval and early adult experiences on the behavioural responses of adult males of the aphid parasitoid, Aphidius ervi, towards volatiles from the host-plant complex (HPC) and from conspecific females were evaluated. Two experience factors were considered: host diet (normal diet=ND; artificial diet=AD), and eclosion, i.e. extraction or non-extraction of the parasitoid larva from the parasitised aphid (extracted=EX; non-extracted=NE). Thus, four treatments were set up: ND/NE, ND/EX, AD/NE and AD/EX. Glass Y-tube olfactometers were used to investigate the responses of adult A. ervi males to the odour sources used. Males from the ND/NE treatment showed a shorter latency to the first choice of olfactometer arms, displayed a marked preference towards the HPC olfactometer arm
Antipredator responses of aphids to parasitoids change as a function of aphid physiological state
Under predation risk, prey may prioritize antipredator behaviours and sacrifice feeding. However, energetically constrained animals may choose to sacrifice or change antipredator responses and accept relatively greater risk in order to secure food. In this last case, the antipredator tactics chosen must balance safety and feeding in such a way that costs are minimized and benefits maximized. We studied the antipredator behaviour of pea aphid, Acyrthosiphon pisum (Harris) (Hemiptera: Aphididae) subjected to different periods of food deprivation, against the parasitoid Aphidius ervi (Hymenoptera: Braconidae). As the energetic internal stress of aphids increased, the predominant antipredator response changed from walking away and dropping to kicking behaviour, and parasitization avoidance decreased. Parasitoids did not show preference between food-deprived and nonfood-deprived aphids. Dropping and walking away reduced parasitization from 50 to 33%. These results support the hypothesis th
Stress in the Educational System as a Potential Source of Epigenetic Influences on Childrens Development and Behavior
Despite current advances on the relevance of environmental cues and epigenetic mechanisms in biological processes, including behavior, little attention has been paid to the potential link between epigenetic influences and educational sciences. For instance, could the learning environment and stress determine epigenetic marking, affecting students behavior development? Could this have consequences on educational outcomes? So far, it has been shown that environmental stress influences neurological processes and behavior both in humans and rats. Through epigenetic mechanisms, offspring from stressed individuals develop altered behavior without any exposure to traumatizing experiences. Methylated DNA and noncoding RNAs regulate neurological processes such as synaptic plasticity and brain cortex development in children. The malfunctioning of these processes is associated with several neurological disorders, and these findings open up new avenues for the design of enriched environments for education and therapy. In this article, we discuss current cases of stress and behavioral disorders found in youngsters, and highlight the importance of considering epigenetic processes affecting the development of cognitive abilities and learning within the educational environment and for the development of teaching methodologies.Funding Agencies|Universidad Metropolitana de Ciencias de la Educacion [FIF 04-14 DIUMCE]; ERC Genewell grant [322206]; Escher Fund for Autism; Research Direction of Metropolitan University of Educational Sciences (DIUMCE)</p