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991.
Jessica L. Will Hyun Seok Kim Jessica Clarke John C. Painter Justin C. Fay Audrey P. Gasch 《PLoS genetics》2010,6(4)
A major goal in evolutionary biology is to understand how adaptive evolution has influenced natural variation, but identifying loci subject to positive selection has been a challenge. Here we present the adaptive loss of a pair of paralogous genes in specific Saccharomyces cerevisiae subpopulations. We mapped natural variation in freeze-thaw tolerance to two water transporters, AQY1 and AQY2, previously implicated in freeze-thaw survival. However, whereas freeze-thaw–tolerant strains harbor functional aquaporin genes, the set of sensitive strains lost aquaporin function at least 6 independent times. Several genomic signatures at AQY1 and/or AQY2 reveal low variation surrounding these loci within strains of the same haplotype, but high variation between strain groups. This is consistent with recent adaptive loss of aquaporins in subgroups of strains, leading to incipient balancing selection. We show that, although aquaporins are critical for surviving freeze-thaw stress, loss of both genes provides a major fitness advantage on high-sugar substrates common to many strains'' natural niche. Strikingly, strains with non-functional alleles have also lost the ancestral requirement for aquaporins during spore formation. Thus, the antagonistic effect of aquaporin function—providing an advantage in freeze-thaw tolerance but a fitness defect for growth in high-sugar environments—contributes to the maintenance of both functional and nonfunctional alleles in S. cerevisiae. This work also shows that gene loss through multiple missense and nonsense mutations, hallmarks of pseudogenization presumed to emerge after loss of constraint, can arise through positive selection. 相似文献
992.
Hatıra Taşkın Saadet Büyükalaca Hasan Hüseyin Doğan Stephen A. Rehner Kerry O’Donnell 《Fungal genetics and biology : FG & B》2010,47(8):672-682
A collection of 247 true morels (Morchella spp.) primarily from the Mediterranean and Aegean Regions of Southern Turkey, were analyzed for species diversity using partial RNA polymerase I (RPB1) and nuclear ribosomal large subunit (LSU) rDNA gene sequences. Based on the result of this initial screen, 62 collections representing the full range of genetic diversity sampled were subjected to multigene phylogenetic species recognition based on genealogical concordance (GCPSR). The 62-taxon dataset consisted of partial sequences from three nuclear protein-coding genes, RNA polymerase I (RPB1), RNA polymerase II (RPB2), translation elongation factor (EF1-α), and partial LSU rDNA gene sequences. Phylogenetic analyses of the individual and combined datasets, using maximum parsimony (MP) and maximum likelihood (ML), yielded nearly fully resolved phylogenies that were highly concordant topologically. GCPSR analysis of the 62-taxon dataset resolved 15 putative phylogenetically distinct species. The early diverging Elata (black morels) and Esculenta Clades (yellow morels) were represented, respectively, by 13 and two species. Because a Latin binomial can be applied with confidence to only one of the 15 species (Morchella semilibera), species were identified by clade (Mel for Elata and Mes for Esculenta) followed by a unique Arabic number for each species within these two clades. Eight of the species within the Elata Clade appear to be novel, including all seven species within the Mel-20-to-31 subclade and its sister designated Mel-25. Results of the present study provide essential data for ensuring the sustainability of morel harvests through the formulation of sound conservation policies. 相似文献
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995.
Landfield Qwynn Saito Mitsuo Hashim Audrey Canals-Baker Stefanie Sershen Henry Levy Efrat Saito Mariko 《Neurochemical research》2021,46(11):2909-2922
Neurochemical Research - Cocaine is a highly addictive stimulant with diverse effects on physiology. Recent studies indicate the involvement of extracellular vesicles (EVs) secreted by neural cells... 相似文献
996.
Krista L. McGuire Sara G. Payne Matthew I. Palmer Caitlyn M. Gillikin Dominique Keefe Su Jin Kim Seren M. Gedallovich Julia Discenza Ramya Rangamannar Jennifer A. Koshner Audrey L. Massmann Giulia Orazi Adam Essene Jonathan W. Leff Noah Fierer 《PloS one》2013,8(3)
In urban environments, green roofs provide a number of benefits, including decreased urban heat island effects and reduced energy costs for buildings. However, little research has been done on the non-plant biota associated with green roofs, which likely affect their functionality. For the current study, we evaluated whether or not green roofs planted with two native plant communities in New York City functioned as habitats for soil fungal communities, and compared fungal communities in green roof growing media to soil microbial composition in five city parks, including Central Park and the High Line. Ten replicate roofs were sampled one year after planting; three of these roofs were more intensively sampled and compared to nearby city parks. Using Illumina sequencing of the fungal ITS region we found that green roofs supported a diverse fungal community, with numerous taxa belonging to fungal groups capable of surviving in disturbed and polluted habitats. Across roofs, there was significant biogeographical clustering of fungal communities, indicating that community assembly of roof microbes across the greater New York City area is locally variable. Green roof fungal communities were compositionally distinct from city parks and only 54% of the green roof taxa were also found in the park soils. Phospholipid fatty acid analysis revealed that park soils had greater microbial biomass and higher bacterial to fungal ratios than green roof substrates. City park soils were also more enriched with heavy metals, had lower pH, and lower quantities of total bases (Ca, K, and Mg) compared to green roof substrates. While fungal communities were compositionally distinct across green roofs, they did not differentiate by plant community. Together, these results suggest that fungi living in the growing medium of green roofs may be an underestimated component of these biotic systems functioning to support some of the valued ecological services of green roofs. 相似文献
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998.
Christine Archimbaud Lemlih Ouchchane Audrey Mirand Martine Chambon Fran?ois Demeocq André Labbé Henri Laurichesse Jeannot Schmidt Pierre Clavelou Olivier Auma?tre Christel Regagnon Jean-Luc Bailly Cécile Henquell Hélène Peigue-Lafeuille 《PloS one》2013,8(7)
Enteroviruses (EVs) are a major cause of aseptic meningitis, and RNA detection using molecular assay is the gold standard diagnostic test. The aim of this study was to assess the impact of an EV positive diagnosis on the clinical management of patients admitted for meningitis over the course of two observational study periods (2005 and 2008–09) in the same clinical departments. We further investigated in multivariate analysis various factors possibly associated with hospital length of stay (LOS) in all age groups (infants, children, and adults). The results showed an overall improvement in the management of patients (n = 142) between the study periods, resulting in a significantly shorter hospital LOS for adults and children, and a shorter duration of antibiotic use for adults and infants. In multivariate analysis, we observed that the time from molecular test results to discharge of patients and the median duration of antibiotic treatment were associated with an increase in LOS in all age groups. In addition, among adults, the turnaround time of the molecular assay was significantly correlated with LOS. The use of CT scan in children and hospital admission outside the peak of EV prevalence in infants tended to increase LOS. In conclusion, the shorter length of stay of patients with meningitis in this study was due to various factors including the rapidity of the EV molecular test (particularly in adults), greater physician responsiveness after a positive result (in adults and children), and greater experience on the part of physicians in handling EV meningitis, as evidenced by the shorter duration of antibiotic use in adults and infants. 相似文献
999.
Nathan F. Bendik Thomas A. Morrison Andrew G. Gluesenkamp Mark S. Sanders Lisa J. O’Donnell 《PloS one》2013,8(3)
Despite recognition that nearly one-third of the 6300 amphibian species are threatened with extinction, our understanding of the general ecology and population status of many amphibians is relatively poor. A widely-used method for monitoring amphibians involves injecting captured individuals with unique combinations of colored visible implant elastomer (VIE). We compared VIE identification to a less-invasive method – computer-assisted photographic identification (photoID) – in endangered Jollyville Plateau salamanders (Eurycea tonkawae), a species with a known range limited to eight stream drainages in central Texas. We based photoID on the unique pigmentation patterns on the dorsal head region of 1215 individual salamanders using identification software Wild-ID. We compared the performance of photoID methods to VIEs using both ‘high-quality’ and ‘low-quality’ images, which were taken using two different camera types and technologies. For high-quality images, the photoID method had a false rejection rate of 0.76% compared to 1.90% for VIEs. Using a comparable dataset of lower-quality images, the false rejection rate was much higher (15.9%). Photo matching scores were negatively correlated with time between captures, suggesting that evolving natural marks could increase misidentification rates in longer term capture-recapture studies. Our study demonstrates the utility of large-scale capture-recapture using photo identification methods for Eurycea and other species with stable natural marks that can be reliably photographed. 相似文献
1000.
Audrey Vizeneux Aude Hilfiger Jér?me Bouligand Monique Pouillot Sylvie Brailly-Tabard Anu Bashamboo Ken McElreavey Raja Brauner 《PloS one》2013,8(10)