Conditional mutualism emerges from a largely antagonistic species network

O correcto estadiamento do cancro do pulmão é importante porque as opções terapêuticas e o prognóstico variam significativamente com o estadio da doença. Este, tal como é feito para outros tumores sólidos, baseia-se no sistema TNM. A tomografia computorizada torácica é importante no estudo anatómico do tumor, da sua proximidade com estruturas locais e na invasão dos gânglios linfáticos hilares e mediastínicos. A tomografia por emissão de positrões fornece informação acerca da actividade funcional dos tecidos, tendo maiores sensibilidade e especificidade que a tomografia computorizada no estadiamento do mediastino. A avaliação clínica, que é composta pela história aprofundada e exame físico, continua a ser o melhor meio de predizer acerca de doença metastática. Se esta for negativa, estudos de imagem posteriores como a tomografia computorizada cerebral, cintigrama ósseo ou tomografia computorizada abdominal são desnecessários e a pesquisa de doença metastática está completa. Caso existam sinais ou sintomas de metastização, deverá ser iniciada uma sequência de exames de imagem, de acordo com aos dados obtidos na avaliação clínica. Uma grande variedade de exames invasivos está disponível para o estadiamento do cancro do pulmão. Cada um deles tem especificidades técnicas e de acuidade diagnóstica que os tornam mais ou menos apropriados consoante a localização da lesão. Assim, a comparação directa entre estes testes invasivos não é possível e o problema é definir qual dos procedimentos é mais útil em cada situação. O estadiamento molecular pode vir a ser um importante meio no estadiamento e estratificação prognóstica dos doentes com cancro do pulmão. No entanto ainda existem alguns problemas que têm limitado a aplicação deste conceito.The correctly staging of lung cancer is important because the treatment options and prognosis differ significantly with the stage of disease. This, as is done for other solid tumors, based on the TNM system. Chest TC imaging is important in the study of the anatomy of tumor, its proximity with local structures and the invasion of mediastinal and hilar lymph nodes. Positron emission tomography provides information about the functional activity of tissues with greater sensitivity and specificity than chest CT in the staging of the mediastinum. The clinical evaluation, which is made by thorough history and physical examination, remains the best way to predict about metastatic disease. If this is negative, further imaging studies such as CT scan of the head, bone scan or abdominal CT scan are unnecessary and the search for metastatic disease is complete. If there are signs or symptoms of metastasis, should be initiated a series of imaging tests, according to data obtained in the clinical evaluation. A variety of invasive tests are available for the staging of lung cancer. Each of them has specific technical and diagnostic accuracy that makes them more or less appropriate depending on the location of the lesion. Thus, direct comparisons between these invasive tests are not possible and the problem is to define which procedures are most useful in each situation. Molecular staging may prove to be an important tool in the staging and prognostic stratification of patients with lung cancer. However, there are still some problems that have limited the application of the concept

Bacterial symbiont sharing in <i>Megalomyrmex</i> social parasites and their fungus-growing ant hosts

Bacterial symbionts are important fitness determinants of insects. Some hosts have independently acquired taxonomically related microbes to meet similar challenges, but whether distantly related hosts that live in tight symbiosis can maintain similar microbial communities has not been investigated. Varying degrees of nest sharing between Megalomyrmex social parasites (Solenopsidini) and their fungus‐growing ant hosts (Attini) from the genera Cyphomyrmex, Trachymyrmex and Sericomyrmex allowed us to address this question, as both ant lineages rely on the same fungal diet, interact in varying intensities and are distantly related. We used tag‐encoded FLX 454 pyrosequencing and diagnostic PCR to map bacterial symbiont diversity across the Megalomyrmex phylogenetic tree, which also contains free‐living generalist predators. We show that social parasites and hosts share a subset of bacterial symbionts, primarily consisting of Entomoplasmatales, Bartonellaceae, Acinetobacter, Wolbachia and Pseudonocardia and that Entomoplasmatales and Bartonellaceae can co‐infect specifically associated combinations of hosts and social parasites with identical 16S rRNA genotypes. We reconstructed in more detail the population‐level infection dynamics for Entomoplasmatales and Bartonellaceae in Megalomyrmex symmetochus guest ants and their Sericomyrmex amabilis hosts. We further assessed the stability of the bacterial communities through a diet manipulation experiment and evaluated possible transmission modes in shared nests such as consumption of the same fungus garden food, eating of host brood by social parasites, trophallaxis and grooming interactions between the ants, or parallel acquisition from the same nest environment. Our results imply that cohabiting ant social parasites and hosts may obtain functional benefits from bacterial symbiont transfer even when they are not closely related

Seminal fluid compromises visual perception in honeybee queens reducing their survival during additional mating flights

Queens of social insects make all mate-choice decisions on a single day, except in honeybees whose queens can conduct mating flights for several days even when already inseminated by a number of drones. Honeybees therefore appear to have a unique, evolutionarily derived form of sexual conflict: a queen's decision to pursue risky additional mating flights is driven by later-life fitness gains from genetically more diverse worker-offspring but reduces paternity shares of the drones she already mated with. We used artificial insemination, RNA-sequencing and electroretinography to show that seminal fluid induces a decline in queen vision by perturbing the phototransduction pathway within 24-48 hr. Follow up field trials revealed that queens receiving seminal fluid flew two days earlier than sister queens inseminated with saline, and failed more often to return. These findings are consistent with seminal fluid components manipulating queen eyesight to reduce queen promiscuity across mating flights