BUSCADOR RECOLECTA

host_distribution, Feather mites (Astigmata: Analgoidea and Pterolichoidea) are among the most abundant and commonly occurring bird ectosymbionts. Basic questions on the ecology and evolution of feather mites remain unanswered because feather mite species identification is often only possible for adult males, and it is laborious even for specialized taxonomists, thus precluding large-scale identifications. Here, we tested DNA barcoding as a useful molecular tool to identify feather mites from passerine birds. Three hundred and sixty-one specimens of 72 species of feather mites from 68 species of European passerine birds from Russia and Spain were barcoded. The accuracy of barcoding and minibarcoding was tested. Moreover, threshold choice (a controversial issue in barcoding studies) was also explored in a new way, by calculating through simulations the effect of sampling effort (in species number and species composition) on threshold calculations. We found one 200-bp minibarcode region that showed the same accuracy as the full-length barcode (602 bp) and was surrounded by conserved regions potentially useful for group-specific degenerate primers. Species identification accuracy was perfect (100%) but decreased when singletons or species of the Proctophyllodes pinnatus group were included. In fact, barcoding confirmed previous taxonomic issues within the P. pinnatus group. Following an integrative taxonomy approach, we compared our barcode study with previous taxonomic knowledge on feather mites, discovering three new putative cryptic species and validating three previous morphologically different (but still undescribed) new species., Peer reviewed

Genome-wide cytosine methylation estimates of 200 plants of Helleborus foetidus obtained by HPLC and Methylation Scoring of MSAP data Genome-wide cytosine methylation estimates in young leaves of 200 plants of Helleborus foetidus obtained using HPLC and the percentage of cytosine methylation in CCGG sites obtained by Methylation Scoring of MSAP data. Methylation scoring (MS50) was calculated as the percentage of MSAP loci scored as methylated (condition II + III). HPLC_MS_data_doi_10.5061_dryad.04d0d.txt, Methylation of DNA cytosines affects whether transposons are silenced and genes are expressed, and is a major epigenetic mechanism whereby plants respond to environmental change. Analyses of methylation-sensitive amplification polymorphism (MS-AFLP or MSAP) have been often used to assess methyl-cytosine changes in response to stress treatments and, more recently, in ecological studies of wild plant populations. MSAP technique does not require a sequenced reference genome and provides many anonymous loci randomly distributed over the genome for which the methylation status can be ascertained. Scoring of MSAP data, however, is not straightforward, and efforts are still required to standardize this step to make use of the potential to distinguish between methylation at different nucleotide contexts. Furthermore, it is not known how accurately MSAP infers genome-wide cytosine methylation levels in plants. Here, we analyse the relationship between MSAP results and the percentage of global cytosine methylation in genomic DNA obtained by HPLC analysis. A screening of literature revealed that methylation of cytosines at cleavage sites assayed by MSAP was greater than genome-wide estimates obtained by HPLC, and percentages of methylation at different nucleotide contexts varied within and across species. Concurrent HPLC and MSAP analyses of DNA from 200 individuals of the perennial herb Helleborus foetidus confirmed that methyl-cytosine was more frequent in CCGG contexts than in the genome as a whole. In this species, global methylation was unrelated to methylation at the inner CG site. We suggest that global HPLC and context-specific MSAP methylation estimates provide complementary information whose combination can improve our current understanding of methylation-based epigenetic processes in nonmodel plants., Peer reviewed