Dichlorvos exposure impedes extraction and amplification of DNA from insects in museum collections

<p>Abstract</p> <p>Background</p> <p>The insecticides dichlorvos, paradichlorobenzene and naphthalene have been commonly used to eradicate pest insects from natural history collections. However, it is not known how these chemicals affect the DNA of the specimens in the collections. We thus tested the effect of dichlorvos, paradichlorobenzene and naphthalene on DNA of insects (<it>Musca domestica</it>) by extracting and amplifying DNA from specimens exposed to insecticides in two different concentrations over increasing time intervals.</p> <p>Results</p> <p>The results clearly show that dichlorvos impedes both extraction and amplification of mitochondrial and nuclear DNA after relatively short time, whereas paradichlorobenzene and naphthalene do not.</p> <p>Conclusion</p> <p>Collections treated with paradichlorobenzene and naphthalene, are better preserved concerning DNA, than those treated with dichlorvos. Non toxic pest control methods should, however, be preferred due to physical damage of specimens and putative health risks by chemicals.</p

Mitochondrial DNA Evidence and Evolution in Varanoidea (Squamata)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72302/1/j.1096-0031.2001.tb00118.x.pd

Identification of ‘Extinct’ Freshwater Mussel Species Using DNA Barcoding

Freshwater mollusks are highly imperiled, with 70% of the North American species extinct, endangered, or at risk of extinction. Impoundments and other human impacts on the Coosa River of Alabama, Georgia and Tennessee of the southeastern USA alone are believed to have caused 50 mollusk species extinctions, but uncertainty over boundaries among several putatively closely related species makes this number preliminary. Our examination of freshwater mussels collected during an extensive survey of the upper-drainage basin, DNA barcoding and molecular phylogenetic analyses confirm the rediscovery of four morphospecies in the genus Pleurobema (Unionidae) previously thought to be extinct from the upper Coosa basin. A fifth \u27extinct\u27 form was found in an adjoining basin. Molecular data show that the Coosa morphologies represent at least three species-level taxa: Pleurobema decisum, P. hanleyianum and P. stabile. Endemism is higher than currently recognized, both at the species level and for multispecies clades. Prompt conservation efforts may preserve some of these taxa and their ecosystem

Genetic diversity of the pan-european freshwater mussel Anodonta anatina (bivalvia : unionoida) based on CO1 : new phylogenetic insights and implications for conservation

1. The duck mussel, Anodonta anatina, has been described as abundant and widespread in Europe. However, it is listed as near threatened or threatened in several countries owing to severe declines in abundance and/or spatial distribution. 2. Despite its potential ecological importance and conservation status almost nothing is known regarding its genetic diversity. 3. As a preliminary analysis, variation within the cytochrome oxidase 1 mitochondrial gene was determined from European specimens from Portugal in the south west, to Ukraine in the east, and Sweden in the north. 4. Three major mtDNA clades were retrieved: clade 1 includes all the individuals from Iberia, except those from the Ebro basin; clade 2 includes all the European non-Iberian and non-Italian samples; and clade 3 includes all the individuals from Italy and from the Ebro basin. AMOVA analysis revealed significant genetic differences among the three clades. Within each of the major clades, several geographically related haplogroups were also retrieved, especially in Iberia, where four genetically distinct groups (North-West, South-Central, South-West and Ebro) were revealed. 5. Given the evidence of regional declines of A. anatina in Europe, the confirmation of geographically distinct genotypes indicates a need for the development of management strategies directed towards the conservation of localized populationsThis work was supported financially by the Portuguese Foundation for Science and Technology (FCT) project PTDC/AAC-AMB/117688/2010, and partly by the European Regional Development Fund through COMPETE, under the project PEst-C/MAR/LA0015/2011. We would like to thank our collaborators who kindly provided us with tissue samples: Erika Bodis, Karel Douda, Oksana Stolyar, Arpad Benko-Kiss, Nicoletta Riccardi. Marianna Soroka and Larissa Yanovich gave us the exact locations of their previously sequenced animals. We thank Jose Maria Irurita, Jose Miguel Barea Azcon, Keiko Nakamura, Pablo Redin and Esther Penin for all their help during the Spanish field campaigns. Official capture and sampling licences were issued by Junta de Castilla y Leon (Consejeria de Fomento y Medio Ambiente EP/CYL/331/2012, de 17 de Abril de 2012); Junta de Andalucia (Consejeria de Medio Ambiente- SGYB/FOA/AFR/SFS, de 17 de Julio de 2012); Xunta de Galicia (Conselleria de Medio Ambiente- 539/2012 de 15 de Setembro de 2012); Gobierno de Aragon (Direccion General de Conservacion del Medio Natural- 136.071/2012 de 12 de Julio de 2012)

Variation, variability, and the origin of the avian endocranium:Insights from the anatomy of alioramus altai (theropoda: Tyrannosauroidea)

The internal braincase anatomy of the holotype of Alioramus altai, a relatively small-bodied tyrannosauroid from the Late Cretaceous of Mongolia, was studied using high-resolution computed tomography. A number of derived characters strengthen the diagnosis of this taxon as both a tyrannosauroid and a unique, new species (e.g., endocranial position of the gasserian ganglion, internal ramification of the facial nerve). Also present are features intermediate between the basal theropod and avialan conditions that optimize as the ancestral condition for Coelurosauria--a diverse group of derived theropods that includes modern birds. The expression of several primitive theropod features as derived character states within Tyrannosauroidea establishes previously unrecognized evolutionary complexity and morphological plasticity at the base of Coelurosauria. It also demonstrates the critical role heterochrony may have played in driving patterns of endocranial variability within the group and potentially reveals stages in the evolution of neuroanatomical development that could not be inferred based solely on developmental observations of the major archosaurian crown clades. We discuss the integration of paleontology with variability studies, especially as applied to the nature of morphological transformations along the phylogenetically long branches that tend to separate the crown clades of major vertebrate groups

Phylogenetic relationships within Chamaecrista sect. Xerocalyx (Leguminosae, Caesalpinioideae) inferred from the cpDNA trnE-trnT intergenic spacer and nrDNA ITS sequences

Chamaecrista belongs to subtribe Cassiinae (Caesalpinioideae), and it comprises over 330 species, divided into six sections. The section Xerocalyx has been subjected to a profound taxonomic shuffling over the years. Therefore, we conducted a phylogenetic analysis using a cpDNA trnE-trnT intergenic spacer and nrDNA ITS/5.8S sequences from Cassiinae taxa, in an attempt to elucidate the relationships within this section from Chamaecrista. The tree topology was congruent between the two data sets studied in which the monophyly of the genus Chamaecrista was strongly supported. Our analyses reinforce that new sectional boundaries must be defined in the Chamaecrista genus, especially the inclusion of sections Caliciopsis and Xerocalyx in sect. Chamaecrista, considered here paraphyletic. The section Xerocalyx was strongly supported as monophyletic; however, the current data did not show C. ramosa (microphyllous) and C. desvauxii (macrophyllous) and their respective varieties in distinct clades, suggesting that speciation events are still ongoing in these specimens