Biomarcadores evolutivos de cáncer gástrico en Nariño / Evolutionary biomarkers of gastric cancer in Nariño

Objetivo: Dilucidar el papel de la coevolución del genoma humano y de Helicobacter pylori en la patogenesis gástrica en población de Nariño-Colombia. Materiales y Métodos: Se aisló Helicobacter pylori de biopsias gástricas obtenidas de 292 pacientes con enfermedad gástrica de Nariño. El diagnóstico histológico se realizó por la clasificación de Sydney. Se incluyeron 252 cepas de H. pylori para el análisis MLST, que las asignó a poblaciones ancestrales (hpAfrica1, hpAfrica2, hpEurope, hpEAsia). Para los análisis evolutivos humanos se utilizó Immunochip y el software ESTRUCTURE para determinar proporciones de ascendencia por comparación con 712 secuencias globales de base MLST de H. pylori (http://pubmlst.org/helicobacter). Resultados: Las cepas de H. pylori en Nariño se derivan de cuatro poblaciones ancestrales: Africa (AA1), Europea (AE1 y AE2) y Asia Oriental (AEA). Los aislamientos contenían fracciones sustanciales de ancestría africana AA1 en la costa, y europea, AE2 en la región montañosa. Debido a que la población de montaña tenía un mínimo de ancestría africana del huésped, nos preguntamos si AA1 aumentaba la gravedad de las lesiones gástricas en los sujetos con baja ancestría africana. Tal escenario podría significar una coadaptación interrumpida: disrupción de la coevolución humano-H. pylori. Cuando consideramos a las 56 personas con menos del 17,6% de ancestria africana, encontramos que todas las personas que portaban H. pylori con >19,8% de ancestría africana AA1, n = 20 tenían lesiones severas. Conclusión: Las relaciones coevolutivas humano-H. pylori son biomarcadores importantes de enfermedad gástrica, y la interrupción de estas relaciones desenlazan lesiones gástricas mas avanzadas en Nariño.

Objective: To elucidate the role of the coevolution of the human genome and Helicobacter pylori in gastric pathogenesis in a population from Nariño-Colombia. Materials and Methods: Helicobacter pylori was isolated from gastric biopsies obtained from 292 patients with Nariño gastric disease. The histological diagnosis was made by the Sydney classification. 252 H. pylori isolates were included for MLST analysis, which assigned them to ancestral populations (hpAfrica1, hpAfrica2, hpEurope, hpEAsia). Immunochip was used for human evolutionary analyses. STRUCTURE software to determine ancestry proportions by comparison with 712 global H. pylori MLST base sequences (http://pubmlst.org/helicobacter). Results: The H. pylori strains in Nariño derive from four ancestral populations: African (AA1), European (AE1 and AE2), and East Asian (AEA). The isolates contained substantial fractions of AA1 African ancestry on the coast, and AE2 European ancestry in the mountains. Because the mountain population had minimal African ancestry of the host, we wondered if AA1 increased the severity of gastric lesions in subjects of low African ancestry. Such a scenario could signify disrupted coadaptation: disruption of human-H. pylori coevolution. When we considered the 56 individuals with less than 17.6% African ancestry, we found that all individuals carrying H. pylori with >19.8% AA1 African ancestry, (n = 20) had severe lesions. Conclusion: Human and H. pylori coevolutionary relationships are important biomarkers of gastric disease, and disruption of these relationships results in more advanced gastric lesions in Nariño-Colombia.

Helicobacter pylori: Microorganismo patógeno o mutualista en poblaciones colombianas / Helicobacter pylori: Pathogenic or mutualistic microorganism in Colombian populations / Helicobacter pylori: microrganismo patógeno ou mutualista em populações Colombianas

Introducción: El riesgo de desarrollar cáncer gástrico varía entre continentes, países y regiones. A pesar de que existe una alta prevalencia de Helicobacter pylori su rol como patógeno o mutualista define el riesgo de cáncer gástrico en las regiones de Colombia. Objetivo: Discutir el rol de Helicobacter pylori en el riesgo de cáncer gástrico en Colombia. Materiales y métodos: Revisión de literatura mediante la búsqueda, en las bases de datos LILACS, SciELO, PubMed. Resultados: La coevolución del humano y de Helicobacter pylori; la virulencia de genes cagA, vacA; el tipo de respuesta inmune inflamatoria a Helicobacter pylori (Th1) o antinflamatoria (Th2) y la susceptibilidad humana a cáncer gástrico (IL1β, IL10), junto a la dieta y factores ambientales explican el papel de Helicobacter pylori como patógeno o mutualista asociado al riesgo de cáncer gástrico en Colombia. Conclusiones: Helicobacter pylori tiene un rol mutualista principalmente en poblaciones de bajo riesgo de cáncer gástrico (costas), no obstante, en poblaciones con alto riesgo de cáncer gástrico (andes), su papel como patógeno amerita la erradicación; única estrategia para mitigar la alta incidencia de este cáncer en Colombia.

Introduction: The risk to develop gastric cancer varies between continents, countries and regions. Although there is a high prevalence of Helicobater pylori, its role as either pathogen or mutualistic bacteria defines the risk of gastric cancer in Colombian regions. Objective: To discuss the role of Helicobacter pylori in the risk of gastric cancer in Colombia. Materials and methods: A literature review based on searching LILACS, SciELO, and PubMed databases. Results: Helicobacter pylori role as either a pathogen or mutualistic microorganism associated with gastric cancer risk in Colombia can be explained by analyzing elements such as: human and Helicobacter pylori coevolution; cagA and vacA gene virulence; inflammatory (Th1) or anti-inflammatory (Th2) responses induced by Helicobacter pylori; human susceptibility to gastric cancer (IL1β, IL10); diet; and environmental factors. Conclusions: Even though Helicobacter pylori has a mutualistic role in populations at low gastric cancer risk (coastal regions), its role as a pathogen in populations at higher risk (Andean regions) justifies its eradication as a key strategy to mitigate the incidence of this cancer in Colombia.

Introdução: O risco de desenvolver câncer gástrico varia entre continentes, países e regiões. Embora haja uma alta prevalência de Helicobacter pylori, seu papel como patógeno ou mutualista define o risco de câncer gástrico nas regiões da Colômbia. Objetivo: Discutir o papel do Helicobacter pylori no risco de câncer gástrico na Colômbia. Materiais e métodos: Revisão da literatura por meio da busca, nas bases de dados LILACS, SciELO e PubMed. Resultados: A coevolução de humanos e Helicobacter pylori; a virulência dos genes cagA, vacA; o tipo de resposta imune inflamatória ao Helicobacter pylori (Th1) ou anti-inflamatório (Th2) e a suscetibilidade humana ao câncer gástrico (IL1β, IL10), juntamente com a dieta e fatores ambientais explicam o papel do Helicobacter pylori como patógeno ou mutualista associado ao risco de câncer gástrico na Colômbia. Conclusões: Helicobacter pylori tem um papel mutualista principalmente em populações de baixo risco de câncer gástrico (litoral), porém, em populações com alto risco de câncer gástrico (andes), seu papel como patógeno justifica a erradicação; única estratégia para mitigar a alta incidência deste câncer na Colômbia.

Geriatric infections: Decreased immunity or evolved opportunists?

In host–parasite co-evolution, parasites are assumed to have an advantage owing to their shorter generationtime. Evolution of pathogens within the lifetime of a host individual is implicated as a strong selective force inthe evolution of sex and aging in the host. However, this assumption or its testable predictions have not beenexamined empirically. We classified infectious bacteria and viruses into those that can have continued longterm existence on the host body (group 1) versus those that have only a short-term interaction during an activeinfection (group 2). We surveyed the literature for age-specific incidence data about infections from both thegroups. The age trends of the two groups show contrasting patterns. The incidence of infections by all group 1pathogens showed a 2.28- to 28-fold increase in older ages. In group 2, 6 out of the 9 pathogens showed asignificant declining trend in incidence with age. In both groups, there was greater mortality or morbidityamong the infected in the old-age classes. These patterns are better explained by pathogen evolution than byage-related decline in immunity

The coevolution between telson morphology and venom glands in scorpions (Arachnida)

As in previous contributions to the JVATiTD, the aim of this note is to bring some general information on a particular aspect of the scorpion biology. An attempt is made to explain the possible coevolution of telson morphology and venom glands, which took place during several hundred million years and in particular since scorpions migrated from aquatic to terrestrial environments. Three components can be directly associated with predation and defensive behaviours: (1) morphology of the chelae and structure of the chelae fingers granulations; (2) morphology of the metasoma and in particular of the telson; (3) evolution of tegumentary glands in the telson toward different types of venom glands. Since a number of recent contributions already treated some of these aspects, I will limit my comments to the possible evolution of the telson in relation to the evolution of venom glands. As in previous contributions, the content of this article is basically addressed to non-specialists on scorpions whose research embraces scorpions in several fields such as venom toxins and public health.(AU)

The development of transversal competence of health service managers / O desenvolvimento da competência transversal dos gestores de serviços de saúde

ABSTRACT In their pedagogical projects, health management courses focus on multidisciplinarity, interdisciplinarity, comprehensiveness and transversality, whose main merit is to question health issues from different theoretical perspectives. Analyzing these issues under many perspectives does not necessarily mean the development of transversal competences. The development and application of these competences suppose going beyond integrating curricular contents and theory/practice. They depend on how the knowledge will be articulated to changes at organizational, sectorial and institutional levels and on the coevolution between these competences and changes. It is understood that health services manager role is effectively transversal when he/she: (i) acts at organizational boundaries, fostering interaction between organizations and other actors in the system; (ii) provides (and receives) feedback to (and from) these actors; and (iii) these feedbacks help decision makers to undertake organizational changes to respond to the environment and shape it.

RESUMO Em seus projetos pedagógicos, os cursos de gestão de saúde privilegiam a multidisciplinaridade, interdisciplinaridade, integralidade e transversalidade, cujo principal mérito é problematizar as questões da saúde sob diferentes perspectivas teóricas. Analisar as questões da área da saúde a partir de diversos prismas não implica necessariamente no desenvolvimento de competências transversais. O desenvolvimento e a aplicação dessas competências pressupõem ir além da integração entre conteúdos curriculares e entre teoria e prática. Dependem de como os conhecimentos serão articulados às mudanças nos níveis organizacional, setorial e institucional e da coevolução entre essas competências e essas mudanças. Entende-se que a atuação do gestor de serviços de saúde é efetivamente transversal quando: (i) atua nas fronteiras organizacionais, fomentando a interação entre as organizações e outros atores do sistema; (ii) provê (e recebe) feedbacks para esses (desses) atores; e (iii) esses feedbacks auxiliam os tomadores de decisão a empreender mudanças organizacionais, de modo a responder ao ambiente e a moldá-lo.

Biting the hand that feeds you: wedge-billed hummingbird is a nectar robber of a sicklebill-adapted Andean bellflower / Muerde la mano que le da de comer: Colibrí pico cuña el ladrón de néctar de Centropogon granulosus (Campanulaceae)

Informo sobre el comportamiento de robo de néctar del colibrí pico cuña, Schistes geoffroyi (Trochilidae) en la flor campanulada neotropical, Centropogon granulosus (Campanulaceae). Muchas especies de Centropogon se caracterizan por tener una flor tubular curvada de distintas formas y probablemente especializadas para ser polinizadas por los colibríes de pico curvo (Eutoxeres), como es evidente a partir de la curvatura tanto de la flor como del pico. Debido a la exclusividad de este mutualismo, el robo de néctar ha sido ocasionalmente documentado en Centropogon. Aquí amplío el estudio de robo de néctar de Centropogon incluyendo a Schistes geoffroyi. Esta expansión puede ser un indicador de la alta especialización entre el mutualismo de Centropogon y el colibrí de pico curvo, siendo esta más susceptible al robo de néctar de lo que pensaba previamente. Esto genera preguntas acerca de la evolución de la especialización y parasitismo en este grupo tropical, tanto de las campanuladas como de los colibríes.

I report on nectar robbing behavior of the wedge-billed hummingbird, Schistes geoffroyi (Trochilidae) on the Andean bellflower, Centropogon granulosus (Campanulaceae). Many species of Centropogon are characterized by an abruptly curved corolla tube which is likely specialized for pollination by sicklebill hummingbirds (Eutoxeres), as evident from the matching curvature of flower and bill. Nectar robbing has been documented for some Centropogon spp., but not for sicklebill pollinated C. granulosus. Given recent developments and interest in the Centropogon-sicklebill mutualism, it is pertinent to document any natural history observations that may underlie the ecology and evolution of this pollination system. The establishment of wedge-billed hummingbird as a nectar robber of C. granulosus calls for a new assessment of the ecology and evolution of the highly specialized Centropogon-sicklebill mutualism.

Taxonomy of the Golovinomyces cynoglossi Complex (Erysiphales, Ascomycota) Disentangled by Phylogenetic Analyses and Reassessments of Morphological Traits

The name Golovinomyces cynoglossi s. lat. is traditionally applied to a complex of morphologically similar powdery mildews on hosts of the plant family Boraginaceae. The current species-level taxonomy within this complex is ambiguous due to the lack of phylogenetic examinations. The present study applied phylogenetic methods to clarify the taxonomy of G. cynoglossi s. lat. Phylogenetic analysis of rDNA ITS sequences retrieved from Asian, European and North American specimens revealed that G. cynoglossi s. lat. collections from different hosts involved several species in five clearly separated lineages. Clade I consists primarily of Golovinomyces cynoglossi s. str. on Cynoglossum. Clade III consists of Golovinomyces sequences retrieved from the host genera Symphytum and Pulmonaria. The taxa within clade III are now assigned to G. asperifoliorum comb. nov. Clade V encompasses G. cynoglossi s. lat. on the host genera Bothriospermum, Buglossoides, Echium, Myosotis, and Trigonotis. The taxa within clade V are now assigned to G. asperifolii comb. nov. The species concerned in this study were lecto- and epitypified to stabilize their nomenclature.

Sympatry influence in the interaction of Trypanosoma cruzi with triatomine

Abstract INTRODUCTION: Trypanosoma cruzi, the etiologic agent of Chagas disease, is widely distributed in nature, circulating between triatomine bugs and sylvatic mammals, and has large genetic diversity. Both the vector species and the genetic lineages of T. cruzi present a varied geographical distribution. This study aimed to verify the influence of sympatry in the interaction of T. cruzi with triatomines. Methods: The behavior of the strains PR2256 (T. cruzi II) and AM14 (T. cruzi IV) was studied in Triatoma sordida (TS) and Rhodnius robustus (RR). Eleven fifth-stage nymphs were fed by artificial xenodiagnosis with 5.6 × 103 blood trypomastigotes/0.1mL of each T. cruzi strain. Every 20 days, their excreta were examined for up to 100 days, and every 30 days, the intestinal content was examined for up to 120 days, by parasitological (fresh examination and differential count with Giemsa-stained smears) and molecular (PCR) methods. Rates of infectivity, metacyclogenesis and mortality, and mean number of parasites per insect and of excreted parasites were determined. RESULTS: Sympatric groups RR+AM14 and TS+PR2256 showed higher values of the four parameters, except for mortality rate, which was higher (27.3%) in the TS+AM14 group. General infectivity was 72.7%, which was mainly proven by PCR, showing the following decreasing order: RR+AM14 (100%), TS+PR2256 (81.8%), RR+PR2256 (72.7%) and TS+AM14 (36.4%). CONCLUSIONS: Our working hypothesis was confirmed once higher infectivity and vector capacity (flagellate production and elimination of infective metacyclic forms) were recorded in the groups that contained sympatric T. cruzi lineages and triatomine species.

Evolutionary and Comparative Genomics to Drive Rational Drug Design, with Particular Focus on Neuropeptide Seven-Transmembrane Receptors

Seven transmembrane receptors (7TMRs), also known as G protein-coupled receptors, are popular targets of drug development, particularly 7TMR systems that are activated by peptide ligands. Although many pharmaceutical drugs have been discovered via conventional bulk analysis techniques the increasing availability of structural and evolutionary data are facilitating change to rational, targeted drug design. This article discusses the appeal of neuropeptide-7TMR systems as drug targets and provides an overview of concepts in the evolution of vertebrate genomes and gene families. Subsequently, methods that use evolutionary concepts and comparative analysis techniques to aid in gene discovery, gene function identification, and novel drug design are provided along with case study examples.

Strategies to prevent bacteriophage infection in industrial fermentation / 生物工程学报

During the development of bacteria-based biotechnology, bacteriophage infection is one of the constant threats and troublesome problems in industrial fermentation. The core of puzzled bacteriophage infection is a complex arm race of coevolution between bacteriophages and their hosts where bacteriophage has evolved lots of escaped ways against bacterial resistance mechanisms. The strategies of rationally designing factories and rotation of starter strains could reduce the risk of bacteriophage infection, but often fail to avoid. Genetic engineering to increase bacterial resistance is one of the strategies to prevent bacteriophage infection and more knowledge about bacteriophage and its host is needed. Recently, there are some new findings on bacterial resistance mechanisms which provide new solutions for bacteriophage infection. For example, it is possible for a rational design of resistant strains to use CRISPR-Cas based technologies just based on the sequences of bacteriophages. Moreover, it is also possible to avoid the escape of bacteriophage by iteratively building up resistance levels to generate robust industrial starter cultures. Quorum-sensing signal molecules have recently been proved to be involved in the interactions between bacteria and bacteriophages, which provides a possible way to solve bacteriophage infection from a population level. Finally, the rapid development of bacteriophage genome editing and synthetic biology will bring some new cues for preventing bacteriophage infection in industrial fermentation.

Seed germination after passing through gastrointestinal tract of bats (Chiroptera, Phyllostomidae) / Germinação de sementes após a passagem pelo trato gastrointestinalde morcegos (Chiroptera, Phyllostomidae)

Este estudo teve como objetivo avaliar a germinação de sementes de espécies de Piper, Solanum, Cecropiae Fícus após sua passagem pelo trato gastrointestinal dos morcegos frugívoros Artibeus lituratus, Platyrrhinus lineatus, Carollia perspicillata e Sturnira lilium. Os morcegos e as amostras de frutos/infrutescências foram obtidos no Parque Estadual Mata dos Godoy, Londrina, PR. Para cada espécie vegetal foram considerados o controle e quatro tratamentos, formados pelas sementes obtidas das fezes de cada espécie de morcego: (1) A. lituratus, (2) P. lineatus, (3) C. perspilata e (4) S. lilium. Duzentas sementes foram utilizadas em cada tratamento e foram colocadas para germinar, ao mesmo tempo, em quatro recipientes distribuídos aleatoriamente. Os dados de germinação foram usados para calcular a taxa e o tempo médio de germinação. Somente em duas espécies, Cecropia pachystachya e Ficus eximia, apassagem através do trato gastrointestinal dos animais não produziu alteração significativa. Enquanto, asseis espécies restantes obtiveram diferenças significativas nas taxas e/ou tempos médio de germinação de sementes após passagem dos diásporos pelo trato gastrointestinal de pelo menos uma das espécies de morcegos. Além disso, foi possível observar que a preferência alimentar da espécie de morcego por uma espécie vegetal não alterou significativamente a germinação em relação aos demais. Conclui-se que ao longo do processo evolutivo a coevolução difusa não favoreceu a alteração de padrões de germinação pela preferência alimentar dos morcegos. Todavia, foi observado que os morcegos alteram a taxa e o tempo de germinação das plantas, auxiliando seu estabelecimento, além de serem bons dispersores,mesmo das espécies onde a germinação não foi alterada.

The aim of this study was to evaluate seed germination of Piper, Solanum, Cecropia and Ficus speciesafter their passage through the gastrointestinal tract of frugivorous bats - Artibeus lituratus, Platyrrhinuslineatus, Carollia perspicillata and Sturnira lilium. Both bats and fruits/infrutescences samples were obtained in the Parque Estadual Mata do Godoy, Londrina, Brazil. For each plant species, we considered the control and four treatments, made up by the seeds obtained from the feces of each species of bat:(1) A. lituratus, (2) P. lineatus, (3) C. perspilata and (4) S. lilium. Two hundred seeds were used for each treatment and were germinated at the same time, randomly distributed in four containers. The germination data were used to calculate the rate and the average germination time. In only two species, C. pachystachya and F. eximia, the passage through the gastrointestinal tract of animals produced no significant change. While the remaining six species had significant differences in the rates and / oraverage time of seed germination after passage through the gastrointestinal tract of at least one speciesof bats. Moreover, food preference of bat species for one plant species did not significantly change seed germination in relation to other plants. The conclusion is that over evolutionary process, diffuseco-evolution did not favor changing germination standards for food preference of bats. However, it was observed that bats modify the rate and germination time of plants assisting its establishment, besides being good dispersers, even of the species where germination has not been changed.

Progress of research on parasitic adaptability of schistosome and its applica-tion value / 中国血吸虫病防治杂志

The larval and adult schistosomes can effectively establish the stable parasitic relationship with their final hosts and then maintain the parasitism for a long time,due to the successful adaptation to their parasitic lifestyle. This paper reviews the progress of research on parasitic adaptability of schistosomes in several respects,and demonstrates the application value of schisto-somal genes related to parasitic adaptability in schistosomiasis control and exploitation of natural active molecules.

Biologia, subjetividade e alteridade / Biology, subjectivity and alterity / Biología, subjetividad y alteridad

Este artigo tem a finalidade de apresentar e discutir o conceito de alteridade biológica. A questão da alteridade, do ponto de vista humano, se expressa além da dimensão abordada pela biologia; mas a faculdade de realizar escolhas conscientes e de se constituir na relação com o outro, teria uma raiz na biologia e estaria inscrita na existência de todo ser vivo. Estudos recentes da biologia e da filosofia apontam para novas formas de pensar a relação entre os seres vivos do ponto de vista ontogênico e coevolutivo. A condição humana é anteriormente biológica. Conceber a alteridade, enquanto natureza peculiar dos seres vivos, pode apontar para uma forma diferente e integrada de se compreender o corpo humano e as questões éticas relativas ao vivo e às práticas em saúde.

This article aims to present and discuss the concept of biological alterity. From a human point of view this issue is expressed beyond the dimension approached by biology. However, the ability to make conscious decisions and be constituted in the relationship with the other would have a biological root and would be embedded in the existence of every living being. Recent biology and philosophy studies have shown new ways of thinking about the relation among living beings from the point of view of ontogeny and co-evolution. The human condition has primarily biological origins. Addressing alterity as a peculiar nature of the living beings may indicate a different and integrated way of understanding human body as well as the ethical issues related to life and health practices.

Este artículo tiene la finalidad de presentar y discutir el concepto de alteridad biológica. La cuestión de la alteridad, del punto de vista humano, se expresa más allá de la dimensión planteada por la biología; pero la facultad de realizar escogimientos conscientes y de constituirse en la relación con el otro tendría una raíz en la biología y estaría inscrita en la existencia de todo ser viviente. Estudios recientes de la biología y de la filosofía apuntan para nuevas formas de pensar la relación entre los seres vivientes del punto de vista ontogénico y co-evolutivo. La condición humana es anteriormente biológica. Comprender la alteridad como naturaleza propia de los seres vivientes puede apuntar una forma integrada y diferente de comprender el cuerpo humano y las cuestiones éticas relativas al viviente y a las prácticas en salud.

Modelos explicativos em saúde coletiva: abordagem biopsicossocial e auto-organização / Explanatory models in collective health: bio-psycho-social complexity and self-organization

A complexidade do processo saúde-doença tem ensejado a proposição de uma diversidade de modelos explicativos. Fazemos uma breve revisão dessas propostas, confrontando três perspectivas: o modelo oriundo da Medicina do século XIX, a lógica da História Natural da Doença e o debate epidemiológico no contexto da Medicina Social latino-americana. Tomando-se como referência teórica a ideia de causalidade circular presente na teoria da auto-organização, propomos que os fatores causais privilegiados em cada um dos modelos explicativos acima não seriam conflitantes. Uma noção-chave para se pensar o processo de autoorganização biopsicossocial é o "efeito baldwiniano", que descreve uma relação dialética ou coevolutiva entre processos naturais e socioculturais.

The complexity of the health-disease process has elicited the postulation of a diversity of explanatory models. We make a brief review of the proposals, starting with the biomedical model derived from the 19th century medicine. This model influenced the approach on the natural history of disease, and the debate on epidemiologic models in the context of the Latin-American Social Medicine. Broadening the spectrum of the discussion, we introduce the idea of circular causality, proposed by theories of self-organizing systems. We argue that, in a transdisciplinary perspective, these explanatory models are not conflicting. A key notion to understand these classes of concomitant explanatory models is the "Baldwin Effect", describing a dialectic or coevolutionary relation between nature, social organization and culture.

Ciento cincuent años de pensamiento coevolutivo: la vida es una maraña de interacciones / One Hundred and Fifty Years of Coevolutionary Thinking: Life is a Web of Interactions

La supervivencia y reproducción de la inmensa mayoría de organismos multicelulares dependen de interacciones ecológicas, frecuentemente especializadas, con organismos de otras especies. La coevolución, entendida como el conjunto de cambios evolutivos recíprocos entre especies que ejercen estas interacciones, se reconoce como un proceso continuo que organiza la variabilidad darviniana en complejas redes biológicas. Esta visión dinámica suaviza el conflicto entre la naturaleza armónica de Humboldt y la naturaleza en guerra de Darwin y otros naturalistas del siglo 19. Los cimientos conceptuales de la biología coevolutiva incluyen el papel causal de los microorganismos en las enfermedades, la ubicuidad de las simbiosis, su frecuente caracter especialista y la determinación mendeliana de los desenlaces de tales interacciones. En tanto que son el resultado de la selección natural, los cambios coevolutivos afectan los rasgos hereditarios involucrados en las respectivas interacciones. Como las especies están constituidas por poblaciones genéticamente diversas y estructuradas espacialmente, la coevolución entre dos o más especies dadas puede hacer que estos cambios coevolutivos sean cualitativa o cuantitativamente diferenciales según la localidad, originando mosaicos geográficos. La biología coevolutiva busca construir una atalaya conceptual que amarre la selección natural darviniana con la ecología. Esta nueva perspectiva permite avizorar la compleja maraña de la vida, y comprender que para conservar las especies es necesario conservar sus interacciones. En este artículo se examina la coevolución desde sus raíces darvinianas, pasando por la identificación de los elementos teóricos indispensables para su formulación, hasta llegar a su interpretación actual.

Multicellular organisms require one or more coevolved ecological interactions to survive and reproduce. Coevolution, the set of reciprocal evolutionary changes between these interacting species, is a continuous process that organizes Darwinian diversity in complex biological webs. This dynamic vision tempers the conflict between Humboldt's harmonious Nature and the warring Nature held by Darwin and other 19th century naturalists. The conceptual foundations of coevolutionary biology include the germ theory of disease, the ubiquity of symbioses, their frequent feature as specialized interactions, and the Mendelian determination of their outcomes. Those coevolutionary changes, driven ultimately by natural selection, affect hereditary traits involved in the interactions. Since species consist of genetically diverse populations with geographic structure, coevolution between two or more given species may cause qualitative or quantitative differential trait changes according to location, giving rise to geographic mosaics. Coevolutionary biology aims at building a conceptual outlook that blends Darwinian natural selection with ecology. This new perspective allows a view of a complex web of life, which will enhance our appreciation of the importance of preserving interactions as a way to preserve species. This article examines coevolution from its Darwinian roots, through the identification of key theoretical elements essential for its formulation, and concludes with its current interpretation.

Pneumocystis diversity as a phylogeographic tool

Parasites are increasingly used to complement the evolutionary and ecological adaptation history of their hosts. Pneumocystis pathogenic fungi, which are transmitted from host-to-host via an airborne route, have been shown to constitute genuine host markers of evolution. These parasites can also provide valuable information about their host ecology. Here, we suggest that parasites can be used as phylogeographic markers to understand the geographical distribution of intra-specific host genetic variants. To test our hypothesis, we characterised Pneumocystis isolates from wild bats living in different areas. Bats comprise a wide variety of species; some of them are able to migrate. Thus, bat chorology and migration behaviour can be approached using Pneumocystis as phylogeographic markers. In the present work, we find that the genetic polymorphisms of bat-derived Pneumocystis are structured by host chorology. Therefore, Pneumocystis intra-specific genetic diversity may constitute a useful and relevant phylogeographic tool.

Specificity of Developmental Resistance in Gypsy Moth (Lymantria dispar) to two DNA-Insect Viruses / 中国病毒学·英文版

Gypsy moth (Lymantria dispar) larvae displayed marked developmental resistance within an instar to L. dispar M nucleopolyhedrovirus (LdMNPV) regardless of the route of infection (oral or intrahemocoelic) in a previous study, indicating that in gypsy moth, this resistance has a systemic component.In this study, gypsy moth larvae challenged with the Amsacta moorei entomopoxvirus (AMEV) showed developmental resistance within the fourth instar to oral, but not intrahemocoelic, inoculation. In general, gypsy moth is considered refractory to oral challenge with AMEV, but in this study, 43% mortality occurred in newly molted fourth instars fed a dose of 5×106 large spheroids of AMEV; large spheroids were found to be more infectious than small spheroids when separated by a sucrose gradient. Developmental resistance within the fourth instar was reflected by a 2-fold reduction in mortality (18%-21%) with 5×106 large spheroids in larvae orally challenged at 24, 48 or 72 h post-molt. Fourth instars were highly sensitive to intrahemocoelic challenge with AMEV; 1PFU produced approximately 80% mortality regardless of age within the instar. These results indicate that in gypsy moth, systemic developmental resistance may be specific to LdMNPV, reflecting a co-evolutionary relationship between the baculovirus and its host.

Pathogenetic Consequences of Cytomegalovirus-Host Co-evolution / 中国病毒学·英文版

Co-evolution has been shown to result in an adaptive reciprocal modification in the respective behaviors of interacting populations over time.In the case of host-parasite co-evolution,the adaptive behavior is most evident from the reciprocal change in fitness of host and parasite-manifested in terms of pathogen survival versus host resistance.Cytomegaloviruses and their hosts represent a pairing of populations that has co-evolved over hundreds of years.This review explores the pathogenetic consequences emerging from the behavioral changes caused by co-evolutionary forces on the virus and its host.

Coadaptation and malaria control

Malaria emerges from a disequilibrium of the system 'human-plasmodium-mosquito' (HPM). If the equilibrium is maintained, malaria does not ensue and the result is asymptomatic plasmodium infection. The relationships among the components of the system involve coadaptive linkages that lead to equilibrium. A vast body of evidence supports this assumption, including the strategies involved in the relationships between plasmodium and human and mosquito immune systems, and the emergence of resistance of plasmodia to antimalarial drugs and of mosquitoes to insecticides. Coadaptive strategies for malaria control are based on the following principles: (1) the system HPM is composed of three highly complex and dynamic components, whose interplay involves coadaptive linkages that tend to maintain the equilibrium of the system; (2) human and mosquito immune systems play a central role in the coadaptive interplay with plasmodium, and hence, in the mainten-ance of the system's equilibrium; the under- or overfunction of human immune system may result in malaria and influence its severity; (3) coadaptation depends on genetic and epigenetic phenomena occurring at the interfaces of the components of the system, and may involve exchange of infectrons (genes or gene fragments) between the partners; (4) plasmodia and mosquitoes have been submitted to selective pressures, leading to adaptation, for an extremely long while and are, therefore, endowed with the capacity to circumvent both natural (immunity) and artificial (drugs, insecticides, vaccines) measures aiming at destroying them; (5) since malaria represents disequilibrium of the system HPM, its control should aim at maintaining or restoring this equilibrium; (6) the disequilibrium of integrated systems involves the disequilibrium of their components, therefore the maintenance or restoration of the system's equilibrium depend on the adoption of integrated and coordinated measures acting on all components,...

Trophobiosis Between Formicidae and Hemiptera (Sternorrhyncha and Auchenorrhyncha): an Overview / Trofobiose Entre Formicidae e Hemiptera (Sternorrhyncha e Auchenorrhyncha): Uma Visão Geral

Fêz-se uma revisão sobre a relação conhecida como trofobiose e que ocorre de forma convergente entre formigas e diferentes grupos de Hemiptera Sternorrhyncha e Auchenorrhyncha (até então conhecidos como 'Homoptera'). As principais características dos 'Homoptera' e dos Formicidae que favorecem as interações trofobióticas, tais como a excreção de honeydew por insetos sugadores, atendimento por formigas e necessidades fisiológicas dos dois grupos de insetos, são discutidas. Aspectos da sua evolução convergente são apresentados. O sistema mais arcaico não é exatamente trofobiótico, as forrageadoras coletam o honeydew despejado ao acaso na folhagem por indivíduos ou grupos de 'Homoptera' não associados. As relações trofobióticas mais comuns são facultativas, no entanto, esta forma de mutualismo é extremamente diversificada e é responsável por numerosas adaptações fisiológicas, morfológicas ou comportamentais entre os 'Homoptera', em particular Sternorrhyncha. As trofobioses mais diferenciadas são verdadeiras simbioses onde as adaptações mais extremas são observadas do lado dos 'Homoptera'. Ao mesmo tempo, as formigas mostram adaptações comportamentais que resultam de um longo período de coevolução. Considerando-se os insetos sugadores como principais pragas dos cultivos em nível mundial, as implicações das relações trofobióticas são discutidas no contexto das comunidades de insetos em geral, focalizando os problemas que geram em Manejo Integrado de Pragas (MIP), em particular.

In this paper, the mutualistic relationship known as trophobiosis, which occurs convergently between ants and several groups of Hemiptera Sternorrhyncha and Auchenorrhyncha (formerly 'Homoptera') is reviewed. The main characteristics of 'Homoptera' and Formicidae which favor trophobiotic interactions, such as honeydew excretion by sap-sucking insects, ant attendance and physiological needs of both insects groups, are discussed. Aspects of the convergent evolution are presented. The most archaic system is not trophobiotic per se, foragers collect the honeydew casually expelled on the foliage by individuals or groups of non-associated 'Homoptera'. The commonest trophobiotic relationships are facultative; therefore, this form of mutualism is extremely diversified and is responsible for a range of physiological, morphological and behavioral adaptations by the 'Homoptera', mainly Sternorrhyncha. The more differentiated trophobioses are true symbioses where the most extreme changes can be observed on the 'Homoptera' side. Meanwhile, the ants show mainly behavioral adaptations resulting from a long coevolutive process. Considering the situation of sap-sucking insects as main crop pests worldwide, implications of trophobiotic relationships are discussed in the context of insect communities, in general, and on the problems that imply to Integrated Pest Management (IPM) in particular.