Genomic Signatures Among Acanthamoeba polyphaga Entoorganisms Unveil Evidence of Coevolution.

The definition of a genomic signature (GS) is "the total net response to selective pressure". Recent isolation and sequencing of naturally occurring organisms, hereby named entoorganisms, within Acanthamoeba polyphaga, raised the hypothesis of a common genomic signature despite their diverse and unrelated evolutionary origin. Widely accepted and implemented tests for GS detection are oligonucleotide relative frequencies (OnRF) and relative codon usage (RCU) surveys. A common pattern and strong correlations were unveiled from OnRFs among A. polyphaga's Mimivirus and virophage Sputnik. RCU showed a common A-T bias at third codon position. We expanded tests to the amoebal mitochondrial genome and amoeba-resistant bacteria, achieving strikingly coherent results to the aforementioned viral analyses. The GSs in these entoorganisms of diverse evolutionary origin are coevolutionarily conserved within an intracellular environment that provides sanctuary for species of ecological and biomedical relevance.

Epigenética y salud: un análisis desde el pensamiento complejo / Epigenetics and health: A complex-thought rooted analysis / Epigenética e saúde: uma análise a partir do pensamento complexo

La epigenética es el estudio de los cambios de los genes y su expresión que no generan modificaciones en la secuencia de ADN. Esta implica una serie de mecanismos como la metilación de citosinas del ADN, lo cual se manifiesta en el fenotipo y genera heredabilidad, también llamada heren-cia "suave y fuerte". Aquí es importante recordar que el fenotipo es una condición emergente del genotipo y de la epigenética. La epigenética mantiene una correcta impronta genómica en condiciones naturales y sin perturbaciones, por el contrario, anormalidades epigenéticas generan una expresión génica y fenotípica inapropiada. Las modifica-ciones fenotípicas se presentan en plantas, animales y seres humanos, lo que finalmente se expresa en los ecosistemas generando una condición emergente más allá de la condición humana: la salud. De acuerdo a lo anterior y desde la perspectiva del pensamiento complejo, la salud es la expresión de la vida per se, razón por la cual la epigenética forma parte de los factores que permiten la emergencia de la salud. En otras palabras, la salud surge como consecuencia de la interacción entre genética, cultura, sociedad, economía, pensamiento, vivencias y experiencias, y es el reflejo de lo que nos hace plenamente humanos.

Epigenetics refers to the study of gene-changes and its expression without altering DNA sequencing. It implies a series of mechanisms such as DNA cytokine methylation. Such mechanism generates heritability and is expressed in the phenotype. Heritability has also become known as soft and strong heredity. The phenotype is an emergent condition stemming from both the genotype and Epigenetics, thus responding to the four dimensions of biological evolution. Under natural, undisturbed conditions, Epigenetics maintains an appropriate genomic imprinting, while epigenetic abnormalities create gene and phenotypic inappropriate expressions. Phenotypic modifications are also present in plants, animals and human beings. Such, ultimately is expressed in ecosystems generating an emerging condition that stretches beyond the human condition and constitutes that which is referred to as health. According to the complex thought approach, health goes beyond determination and balance; health is the very expression of life per se. It emerges as a consequence of genetics, economics, thought and experiences, encompassing that which reflects what makes us fully humans

Epigenética é o estudo das alterações genéticas e de sua expressão sem gerar modificações na sequência do DNA. Envolve uma série de mecanismos, como a metilação da DNA pela citosina, que se manifesta no fenótipo, gerando herdabilidade, denominada herança "mole e forte". O fenótipo é uma condição emergen-te do genótipo e, por sua vez, da epigenética, respondendo às quatro dimensões da evolução biológica. A epigenética em condições naturais, sem distúrbios, mantém uma impressão genómica certa, ao contrário, as anormalidades epigenéticas geram um gene inadequado e expressão fenotípica. Da mesma forma, modificações fenotípicas são apresentadas em plantas, animais e seres humanos, que são finalmente expressas em ecossistemas, gerando uma condição emergente além da condição humana: Saúde. De acordo com o exposto e sob a perspectiva do pensamento complexo, a saúde vai além da determinação, do equilíbrio, sendo a expressão da vida em si. A epigenética é uma dimensão que infere na emergência, mas não um fator determinístico. Finalmente, a saúde surge como conseqüência da genética, da cultura, da condição social e econômica, do pensamento, em fim, das experiências, refletindo o que nos torna plenamente humanos.

The geographic mosaic of coevolution in mutualistic networks.

Ecological interactions shape adaptations through coevolution not only between pairs of species but also through entire multispecies assemblages. Local coevolution can then be further altered through spatial processes that have been formally partitioned in the geographic mosaic theory of coevolution. A major current challenge is to understand the spatial patterns of coadaptation that emerge across ecosystems through the interplay between gene flow and selection in networks of interacting species. Here, we combine a coevolutionary model, network theory, and empirical information on species interactions to investigate how gene flow and geographical variation in selection affect trait patterns in mutualistic networks. We show that gene flow has the surprising effect of favoring trait matching, especially among generalist species in species-rich networks typical of pollination and seed dispersal interactions. Using an analytical approximation of our model, we demonstrate that gene flow promotes trait matching by making the adaptive landscapes of different species more similar to each other. We use this result to show that the progressive loss of gene flow associated with habitat fragmentation may undermine coadaptation in mutualisms. Our results therefore provide predictions of how spatial processes shape the evolution of species-rich interactions and how the widespread fragmentation of natural landscapes may modify the coevolutionary process.

New insights into the genetic diversity of Leishmania RNA Virus 1 and its species-specific relationship with Leishmania parasites.

Cutaneous leishmaniasis is a neglected parasitic disease that manifests in infected individuals under different phenotypes, with a range of factors contributing to its broad clinical spectrum. One factor, Leishmania RNA Virus 1 (LRV1), has been described as an endosymbiont present in different species of Leishmania. LRV1 significantly worsens the lesion, exacerbating the immune response in both experimentally infected animals and infected individuals. Little is known about the composition and genetic diversity of these viruses. Here, we investigated the relationship between the genetic composition of LRV1 detected in strains of Leishmania (Viannia) braziliensis and L. (V.) guyanensis and the interaction between the endosymbiont and the parasitic species, analyzing an approximately 850 base pair region of the viral genome. We also included one LRV1 sequence detected in L. (V.) shawi, representing the first report of LRV1 in a species other than L. braziliensis and L. guyanensis. The results illustrate the genetic diversity of the LRV1 strains analyzed here, with smaller divergences detected among viral sequences from the same parasite species. Phylogenetic analyses showed that the LRV1 sequences are grouped according to the parasite species and possibly according to the population of the parasite in which the virus was detected, corroborating the hypothesis of joint evolution of the viruses with the speciation of Leishmania parasites.