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21.
With the aim of protecting Mexican diversity, one current governmental task is to complete national biological inventories. In the case of odonate insects, several researchers have hypothesized that species richness is complete (205 dragonflies and 151 damselflies), but there has not been any formal exercise to test this. Thus, we have investigated whether odonate species richness (for Mexican endemics, dragonflies (suborder Anisoptera), damselflies (suborder Zygoptera) and total species) is complete using sample-based and coverage-based rarefaction curves. Along with this, we also showed how good distribution data are in the country. The rarefaction curves have indicated 100% completeness for all groups suggesting that the inventory is complete. However, species' distribution data is highly patchy regarding areas either well (e.g. central Mexico) or badly (e.g. coast of Guerrero and Oaxaca) collected. We encourage researchers to continue odonate sampling in order to support at least three conservation actions: (i) conservation assessment of endangered species; (ii) knowledge of range shifts given rising global temperatures; and (iii) increase public interest and awareness in protected, touristic areas. 相似文献
22.
Aldo Scarpa Katarzyna Sikora Matteo Fassan Anna Maria Rachiglio Rocco Cappellesso Davide Antonello Eliana Amato Andrea Mafficini Matilde Lambiase Claudia Esposito Emilio Bria Francesca Simonato Maria Scardoni Giona Turri Marco Chilosi Giampaolo Tortora Ambrogio Fassina Nicola Normanno 《PloS one》2013,8(11)
Identification of driver mutations in lung adenocarcinoma has led to development of targeted agents that are already approved for clinical use or are in clinical trials. Therefore, the number of biomarkers that will be needed to assess is expected to rapidly increase. This calls for the implementation of methods probing the mutational status of multiple genes for inoperable cases, for which limited cytological or bioptic material is available. Cytology specimens from 38 lung adenocarcinomas were subjected to the simultaneous assessment of 504 mutational hotspots of 22 lung cancer-associated genes using 10 nanograms of DNA and Ion Torrent PGM next-generation sequencing. Thirty-six cases were successfully sequenced (95%). In 24/36 cases (67%) at least one mutated gene was observed, including EGFR, KRAS, PIK3CA, BRAF, TP53, PTEN, MET, SMAD4, FGFR3, STK11, MAP2K1. EGFR and KRAS mutations, respectively found in 6/36 (16%) and 10/36 (28%) cases, were mutually exclusive. Nine samples (25%) showed concurrent alterations in different genes. The next-generation sequencing test used is superior to current standard methodologies, as it interrogates multiple genes and requires limited amounts of DNA. Its applicability to routine cytology samples might allow a significant increase in the fraction of lung cancer patients eligible for personalized therapy. 相似文献
23.
Huaiwei Liu Yuanzhang Sun Kristine Rose M. Ramos Grace M. Nisola Kris Ni?o G. Valdehuesa Won–Keun Lee Si Jae Park Wook-Jin Chung 《PloS one》2013,8(12)
Embden-Meyerhof pathway (EMP) in tandem with 2-C-methyl-D-erythritol 4-phosphate pathway (MEP) is commonly used for isoprenoid biosynthesis in E. coli. However, this combination has limitations as EMP generates an imbalanced distribution of pyruvate and glyceraldehyde-3-phosphate (G3P). Herein, four glycolytic pathways—EMP, Entner-Doudoroff Pathway (EDP), Pentose Phosphate Pathway (PPP) and Dahms pathway were tested as MEP feeding modules for isoprene production. Results revealed the highest isoprene production from EDP containing modules, wherein pyruvate and G3P were generated simultaneously; isoprene titer and yield were more than three and six times higher than those of the EMP module, respectively. Additionally, the PPP module that generates G3P prior to pyruvate was significantly more effective than the Dahms pathway, in which pyruvate production precedes G3P. In terms of precursor generation and energy/reducing-equivalent supply, EDP+PPP was found to be the ideal feeding module for MEP. These findings may launch a new direction for the optimization of MEP-dependent isoprenoid biosynthesis pathways. 相似文献
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Lionel Guy Bj?rn Nystedt Christina Toft Katarzyna Zaremba-Niedzwiedzka Eva C. Berglund Fredrik Granberg Kristina N?slund Ann-Sofie Eriksson Siv G. E. Andersson 《PLoS genetics》2013,9(3)
Gene transfer agents (GTAs) randomly transfer short fragments of a bacterial genome. A novel putative GTA was recently discovered in the mouse-infecting bacterium Bartonella grahamii. Although GTAs are widespread in phylogenetically diverse bacteria, their role in evolution is largely unknown. Here, we present a comparative analysis of 16 Bartonella genomes ranging from 1.4 to 2.6 Mb in size, including six novel genomes from Bartonella isolated from a cow, two moose, two dogs, and a kangaroo. A phylogenetic tree inferred from 428 orthologous core genes indicates that the deadly human pathogen B. bacilliformis is related to the ruminant-adapted clade, rather than being the earliest diverging species in the genus as previously thought. A gene flux analysis identified 12 genes for a GTA and a phage-derived origin of replication as the most conserved innovations. These are located in a region of a few hundred kb that also contains 8 insertions of gene clusters for type III, IV, and V secretion systems, and genes for putatively secreted molecules such as cholera-like toxins. The phylogenies indicate a recent transfer of seven genes in the virB gene cluster for a type IV secretion system from a cat-adapted B. henselae to a dog-adapted B. vinsonii strain. We show that the B. henselae GTA is functional and can transfer genes in vitro. We suggest that the maintenance of the GTA is driven by selection to increase the likelihood of horizontal gene transfer and argue that this process is beneficial at the population level, by facilitating adaptive evolution of the host-adaptation systems and thereby expansion of the host range size. The process counters gene loss and forces all cells to contribute to the production of the GTA and the secreted molecules. The results advance our understanding of the role that GTAs play for the evolution of bacterial genomes. 相似文献
29.
Evelyne Turlin Michel Débarbouillé Katarzyna Augustyniak Anne-Marie Gilles Cécile Wandersman 《PloS one》2013,8(2)
EfeUOB-like tripartite systems are widespread in bacteria and in many cases they are encoded by genes organized into iron-regulated operons. They consist of: EfeU, a protein similar to the yeast iron permease Ftrp1; EfeO, an extracytoplasmic protein of unknown function and EfeB, also an extracytoplasmic protein with heme peroxidase activity, belonging to the DyP family. Many bacterial EfeUOB systems have been implicated in iron uptake, but a prefential iron source remains undetermined. Nevertheless, in the case of Escherichia coli, the EfeUOB system has been shown to recognize heme and to allow extracytoplasmic heme iron extraction via a deferrochelation reaction. Given the high level of sequence conservations between EfeUOB orthologs, we hypothesized that heme might be the physiological iron substrate for the other orthologous systems. To test this hypothesis, we undertook characterization of the Staphylococcus aureus FepABC system. Results presented here indicate: i) that the S. aureus FepB protein binds both heme and PPIX with high affinity, like EfeB, the E. coli ortholog; ii) that it has low peroxidase activity, comparable to that of EfeB; iii) that both FepA and FepB drive heme iron utilization, and both are required for this activity and iv) that the E. coli FepA ortholog (EfeO) cannot replace FepA in FepB-driven iron release from heme indicating protein specificity in these activities. Our results show that the function in heme iron extraction is conserved in the two orthologous systems. 相似文献
30.
Izabela Chojnicka Krzysztof Gajos Katarzyna Strawa Gra?yna Broda Sylwia Fudalej Marcin Fudalej Piotr Stawiński Aleksandra Pawlak Pawe? Krajewski Marcin Wojnar Rafa? P?oski 《PloS one》2013,8(2)