Whole-genome amplification in double-digest RADseq results in adequate libraries but fewer sequenced loci

Whole-genome amplification by multiple displacement amplification (MDA) is a promising technique to enable the use of samples with only limited amount of DNA for the construction of RAD-seq libraries. Previous work has shown that, when the amount of DNA used in the MDA reaction is large, double-digest RAD-seq (ddRAD) libraries prepared with amplified genomic DNA result in data that are indistinguishable from libraries prepared directly from genomic DNA. Based on this observation, here we evaluate the quality of ddRAD libraries prepared from MDA-amplified genomic DNA when the amount of input genomic DNA and the coverage obtained for samples is variable. By simultaneously preparing libraries for five species of weevils (Coleoptera, Curculionidae), we also evaluate the likelihood that potential contaminants will be encountered in the assembled dataset. Overall, our results indicate that MDA may not be able to rescue all samples with small amounts of DNA, but it does produce ddRAD libraries adequate for studies of phylogeography and population genetics even when conditions are not optimal. We find that MDA makes it harder to predict the number of loci that will be obtained for a given sequencing effort, with some samples behaving like traditional libraries and others yielding fewer loci than expected. This seems to be caused both by stochastic and deterministic effects during amplification. Further, the reduction in loci is stronger in libraries with lower amounts of template DNA for the MDA reaction. Even though a few samples exhibit substantial levels of contamination in raw reads, the effect is very small in the final dataset, suggesting that filters imposed during dataset assembly are important in removing contamination. Importantly, samples with strong signs of contamination and biases in heterozygosity were also those with fewer loci shared in the final dataset, suggesting that stringent filtering of samples with significant amounts of missing data is important when assembling data derived from MDA-amplified genomic DNA. Overall, we find that the combination of MDA and ddRAD results in high-quality datasets for population genetics as long as the sequence data is properly filtered during assembly.Organismic and Evolutionary Biolog

Most diverse, most neglected: weevils (Coleoptera: Curculionoidea) are ubiquitous specialized brood-site pollinators of tropical flora

In tropical environments, and especially tropical rainforests, a major part of pollination services is provided by diverse insect lineages. Unbeknownst to most, beetles, and more specifically hyperdiverse weevils (Coleoptera: Curculionoidea), play a substantial role there as specialized mutualist brood pollinators. The latter contrasts with a common view where they are only regarded as plant antagonists. This study aims to provide a comprehensive understanding of what is known about plant-weevil brood-site mutualistic interactions, through a review of the known behavioral, morphological and physiological features found in these systems, and the identification of potential knowledge gaps. To date, plant-weevil associations have been described or indicated in no less than 600 instances. Representatives of major plant lineages are involved in these interactions, which have emerged independently at least a dozen times. Strikingly, these mutualistic interactions are associated with a range of convergent traits in plants and weevils. Plants engaged in weevil-mediated pollination are generally of typical cantharophilous type exhibiting large, white and fragrant flowers or inflorescences and they also show specific structures to host the larval stages of their specialist pollinators. Another characteristic feature is that flowers often perform thermogenesis and exhibit a range of strategies to separate sexual phases, either spatially or temporally. Conversely, lineages of brood-site weevil pollinators present numerous shared behavioral and physiological traits, and often form multispecific assemblages of closely related species on a single host; recent studies also revealed that they generally display a high degree of phylogenetic niche conservatism. This pollination mutualism occurs in all tropical regions, and the contrasts between the known and expected diversity of these systems suggests that a wide range of interactions remain to be described globally. Our early estimates of the species richness of the corresponding weevil clades and the marked pattern of phylogenetic niche conservatism of host use further suggest that weevil-based pollination far exceeds the diversity of other brood-site mutualistic systems, which are generally restricted to one or a few groups of plants. As such, weevil pollinators constitute a relevant model to explore the emergence and evolution of specialized brood-site pollination systems in the tropics

Estrutura genética espacial de populações remasnescentes de algodoeiro arbóreo (Gossypium hirsutum L. R. Marie Gaçamte Hutch) do Estado da Paraíba, Brasil.

O algodoeiro arbóreo ou mocó é uma variedade local de algodão alotetraplóide cultivado pertencente à espécie Gossypium hirsutum r. marie galante Hutch que se desenvolveu a partir de formas cultivadas primitivas no Nordeste do Brasil. Caracterizar a estrutura genética espacial das populações remanescentes deste algodoeiro pode relevante para conservação genética e futuros programas de melhoramento, pois são importantes para comunidades agrícolas locais e apresentam características agronômicas potencialmente importantes para melhoria de cultivares modernas de algodão herbáceo. Assim, objetivou-se com este estudo determinar a estrutura genética espacial entre populações cultivadas de algodoeiro arbóreo do estado da Paraíba, Brasil. Foram selecionadas para o estudo quatro populações remanescentes em diferentes municípios do estado da Paraíba, Brasil.Resumos apresentado no SIMPÓSIO DA REDE DE RECURSOS GENÉTICOS VEGETAIS DO NORDESTE, 4., 2019, Areias. Anais..

Artificial Lighting as a Vector Attractant and Cause of Disease Diffusion

BACKGROUND: Traditionally, epidemiologists have considered electrification to be a positive factor. In fact, electrification and plumbing are typical initiatives that represent the integration of an isolated population into modern society, ensuring the control of pathogens and promoting public health. Nonetheless, electrification is always accompanied by night lighting that attracts insect vectors and changes people's behavior. Although this may lead to new modes of infection and increased transmission of insect-borne diseases, epidemiologists rarely consider the role of night lighting in their surveys. OBJECTIVE: We reviewed the epidemiological evidence concerning the role of lighting in the spread of vector-borne diseases to encourage other researchers to consider it in future studies. DISCUSSION: We present three infectious vector-borne diseases-Chagas, leishmaniasis, and malaria-and discuss evidence that suggests that the use of artificial lighting results in behavioral changes among human populations and changes in the prevalence of vector species and in the modes of transmission. CONCLUSION: Despite a surprising lack of studies, existing evidence supports our hypothesis that artificial lighting leads to a higher risk of infection from vector-borne diseases. We believe that this is related not only to the simple attraction of traditional vectors to light sources but also to changes in the behavior of both humans and insects that result in new modes of disease transmission. Considering the ongoing expansion of night lighting in developing countries, additional research on this subject is urgently needed.National Council for Scientific and Technological Development (CNPq), Brasilia, Brazi

Quantification of milk adulterants (starch, H2O2, and NaClO) using colorimetric assays coupled to smartphone image analysis

In this paper, a colorimetric method for the detection of milk adulterants using smartphone image analysis is reported. This is based on the reactions to detect hydrogen peroxide, sodium hypochlorite, and starch in milk, where a color variation is observed for each substance. The image analysis was performed by using lab-made apps (PhotoMetrix®, and RedGIM®) based on partial least squares regression with the histograms of the red-green-blue images. The image histograms are automatically calculated using the smartphone camera and processed within the app. The results have shown the capability of this method to predict the concentration of the three adulterants, demonstrating the potential of the use of digital images and smartphone applications associated with chemometric tools. This method presents a fast, low-cost, and portable way to quantify adulterants in Cow milk

Rarity of monodominance in hyperdiverse Amazonian forests.

Tropical forests are known for their high diversity. Yet, forest patches do occur in the tropics where a single tree species is dominant. Such "monodominant" forests are known from all of the main tropical regions. For Amazonia, we sampled the occurrence of monodominance in a massive, basin-wide database of forest-inventory plots from the Amazon Tree Diversity Network (ATDN). Utilizing a simple defining metric of at least half of the trees ≥ 10 cm diameter belonging to one species, we found only a few occurrences of monodominance in Amazonia, and the phenomenon was not significantly linked to previously hypothesized life history traits such wood density, seed mass, ectomycorrhizal associations, or Rhizobium nodulation. In our analysis, coppicing (the formation of sprouts at the base of the tree or on roots) was the only trait significantly linked to monodominance. While at specific locales coppicing or ectomycorrhizal associations may confer a considerable advantage to a tree species and lead to its monodominance, very few species have these traits. Mining of the ATDN dataset suggests that monodominance is quite rare in Amazonia, and may be linked primarily to edaphic factors