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https://www.readbyqxmd.com/read/29245157/dynamic-cellular-complexity-of-anoxygenic-phototrophic-sulfur-bacteria-in-the-chemocline-of-meromictic-lake-cadagno
#1
Francesco Danza, Nicola Storelli, Samuele Roman, Samuel Lüdin, Mauro Tonolla
The meromictic Lake Cadagno is characterized by a compact chemocline with high concentrations of anoxygenic phototrophic purple sulfur bacteria (PSB) and green sulfur bacteria (GSB). The co-occurrence of phylogenetically distant bacterial groups such as PSB and GSB in the same ecological niche, makes the chemocline of Lake Cadagno an ideal system for studying the conditions and consequences of coexistence of photosynthetic bacteria populations. In this study, we applied flow cytometry (FCM) as a fast tool to identify metabolic changes due to the production and consumption of inclusion bodies such as sulfur globules (SGBs), and follow population dynamics of closely related anoxygenic photosynthetic sulfur bacteria in their natural environment...
2017: PloS One
https://www.readbyqxmd.com/read/29244744/a-carbon-dioxide-limitation-inducible-protein-cola-supports-the-growth-of-synechococcus-sp-pcc-7002
#2
Ginga Shimakawa, Satoru Watanabe, Chikahiro Miyake
A limitation in carbon dioxide (CO₂), which occurs as a result of natural environmental variation, suppresses photosynthesis and has the potential to cause photo-oxidative damage to photosynthetic cells. Oxygenic phototrophs have strategies to alleviate photo-oxidative damage to allow life in present atmospheric CO₂ conditions. However, the mechanisms for CO₂ limitation acclimation are diverse among the various oxygenic phototrophs, and many mechanisms remain to be discovered. In this study, we found that the gene encoding a CO₂ limitation-inducible protein, ColA, is required for the cyanobacterium Synechococcus sp...
December 15, 2017: Marine Drugs
https://www.readbyqxmd.com/read/29244565/do-sperm-really-compete-and-do-eggs-ever-have-a-choice-adult-distribution-and-gamete-mixing-influence-sexual-selection-sexual-conflict-and-the-evolution-of-gamete-recognition-proteins-in-the-sea
#3
Don R Levitan
The evolution of gametic compatibility and the effectiveness of compatibility, within and across species, depend on whether sperm from different males directly compete for an egg and whether eggs ever have a choice. Direct sperm competition and egg choice depend on whether sperm from different males arrive at an egg in the brief interval between first sperm contact and fertilization. Although this process may be relevant for all sexually reproducing organisms, it is most easily examined in aquatic external fertilizers...
January 2018: American Naturalist
https://www.readbyqxmd.com/read/29244558/loss-of-color-pigmentation-is-maintained-at-high-frequency-in-a-monkey-flower-population
#4
Alex D Twyford, Aaron M Caola, Pratibha Choudhary, Ramesh Raina, Jannice Friedman
Color polymorphisms have long been of evolutionary interest for their diverse roles, including mate choice, predator avoidance, and pollinator attraction. While color variation is often under strong selection, some taxa demonstrate unexpectedly high frequencies of presumed deleterious color forms. Here we show that a genetic variant underlying complete loss of anthocyanin pigmentation has risen to an unexpectedly high frequency of >0.2 in a natural population of the plant Mimulus guttatus. Decreased expression of MYB5 transcription factor is associated with unpigmented morphs...
January 2018: American Naturalist
https://www.readbyqxmd.com/read/29243832/abiotic-rather-than-biotic-filtering-shapes-the-arbuscular-mycorrhizal-fungal-communities-of-european-seminatural-grasslands
#5
Maarten Van Geel, Hans Jacquemyn, Jan Plue, Liina Saar, Liis Kasari, Gerrit Peeters, Kasper van Acker, Olivier Honnay, Tobias Ceulemans
Although it is well known that arbuscular mycorrhizal fungi (AMF) play a key role in the functioning of natural ecosystems, the underlying drivers determining the composition of AMF communities remain unclear. In this study, we established 138 sampling plots at 46 grassland sites, consisting of 26 acidic grasslands and 20 calcareous grasslands spread across eight European countries, to assess the relative importance of abiotic and biotic filtering in driving AMF community composition and structure in both the grassland soils and in the roots of 13 grassland plant species...
December 15, 2017: New Phytologist
https://www.readbyqxmd.com/read/29243182/the-facial-nerve-anatomy-and-associated-disorders-for-oral-health-professionals
#6
Kojiro Takezawa, Grant Townsend, Mounir Ghabriel
The facial nerve, the seventh cranial nerve, is of great clinical significance to oral health professionals. Most published literature either addresses the central connections of the nerve or its peripheral distribution but few integrate both of these components and also highlight the main disorders affecting the nerve that have clinical implications in dentistry. The aim of the current study is to provide a comprehensive description of the facial nerve. Multiple aspects of the facial nerve are discussed and integrated, including its neuroanatomy, functional anatomy, gross anatomy, clinical problems that may involve the nerve, and the use of detailed anatomical knowledge in the diagnosis of the site of facial nerve lesion in clinical neurology...
December 14, 2017: Odontology
https://www.readbyqxmd.com/read/29243147/seasonal-variations-in-size-distribution-water-soluble-ions-and-carbon-content-of-size-segregated-aerosols-over-new-delhi
#7
Pawan Kumar, Sushil Kumar, Sudesh Yadav
Size distribution, water-soluble inorganic ions (WSII), and organic carbon (OC) and elemental carbon (EC) in size-segregated aerosols were investigated during a year-long sampling in 2010 over New Delhi. Among different size fractions of PM10, PM0.95 was the dominant fraction (45%) followed by PM3-7.2 (20%), PM7.2-10 (15%), PM0.95-1.5 (10%), and PM1.5-3 (10%). All size fractions exceeded the ambient air quality standards of India for PM2.5. Annual average mass size distributions of ions were specific to size and ion(s); Ca2+, Mg2+, K+, NO3-, and Cl- followed bimodal distribution while SO42- and NH4+ ions showed one mode in PM0...
December 14, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/29242625/regulation-of-hyperoxia-induced-social-behaviour-in-pristionchus-pacificus-nematodes-requires-a-novel-cilia-mediated-environmental-input
#8
Eduardo Moreno, Bogdan Sieriebriennikov, Hanh Witte, Christian Rödelsperger, James W Lightfoot, Ralf J Sommer
Social behaviours are frequently utilised for defence and stress avoidance in nature. Both Caenorhabditis elegans and Pristionchus pacificus nematodes display social behaviours including clumping and bordering, to avoid hyperoxic stress conditions. Additionally, both species show natural variation in social behaviours with "social" and "solitary" strains. While the single solitary C. elegans N2 strain has evolved under laboratory domestication due to a gain-of-function mutation in the neuropeptide receptor gene npr-1, P...
December 14, 2017: Scientific Reports
https://www.readbyqxmd.com/read/29242595/germline-brca-mutation-in-male-carriers-ripe-for-precision-oncology
#9
REVIEW
Ricardo Romão Nazário Leão, Aryeh Joshua Price, Robert James Hamilton
BACKGROUND: Prostate cancer (PC) is one of the known heritable cancers with individual variations attributed to genetic factors. BRCA1 and BRCA2 are tumour suppressor genes with crucial roles in repairing DNA and thereby maintaining genomic integrity. Germline BRCA mutations predispose to multiple familial tumour types including PC. METHODS: We performed a Pubmed database search along with review of reference lists from prominent articles to capture papers exploring the association between BRCA mtuations and prostate cancer risk and prognosis...
December 14, 2017: Prostate Cancer and Prostatic Diseases
https://www.readbyqxmd.com/read/29242367/subspecies-in-the-global-human-gut-microbiome
#10
Paul I Costea, Luis Pedro Coelho, Shinichi Sunagawa, Robin Munch, Jaime Huerta-Cepas, Kristoffer Forslund, Falk Hildebrand, Almagul Kushugulova, Georg Zeller, Peer Bork
Population genomics of prokaryotes has been studied in depth in only a small number of primarily pathogenic bacteria, as genome sequences of isolates of diverse origin are lacking for most species. Here, we conducted a large-scale survey of population structure in prevalent human gut microbial species, sampled from their natural environment, with a culture-independent metagenomic approach. We examined the variation landscape of 71 species in 2,144 human fecal metagenomes and found that in 44 of these, accounting for 72% of the total assigned microbial abundance, single-nucleotide variation clearly indicates the existence of sub-populations (here termed subspecies)...
December 14, 2017: Molecular Systems Biology
https://www.readbyqxmd.com/read/29242287/the-local-co-existence-pattern-of-selfing-genotypes-in-caenorhabditis-elegans-natural-metapopulations
#11
Aurélien Richaud, Gaotian Zhang, Daehan Lee, Junho Lee, Marie-Anne Félix
To study the interplay of rare outcrossing and metapopulation structure, we focus on the nematode Caenorhabditis elegans Its remarkably low outcrossing rate is at the extreme end of the spectrum for facultative selfing organisms. At the demographic level, C. elegans natural populations undergo boom and bust dynamics on ephemeral resources, the dauer diapause larva acting as the dispersal form. Here we investigate the small-scale genetic structure of C. elegans populations in two localities over several years, using 2b-RAD (Restriction-Associated DNA) sequencing of nearly a thousand individuals...
December 13, 2017: Genetics
https://www.readbyqxmd.com/read/29242156/an-avian-reproduction-study-historical-control-database-a-tool-for-data-interpretation
#12
Pablo Valverde-Garcia, Tim Springer, Vince Kramer, Manousos Foudoulakis, James R Wheeler
Avian reproduction studies are a regulatory requirement for pesticides in many regions. The data often require careful interpretation due to the nature of the study design. Here we present the historical control dataset for bobwhite quail and mallard duck reproduction studies performed at the Evans Analytical Group LLC avian toxicology laboratory over the period 1985-2016. The analysis demonstrates the stability of reproductive parameters over time and good agreement to normal control ranges as required by the regulatory test guidelines...
December 11, 2017: Regulatory Toxicology and Pharmacology: RTP
https://www.readbyqxmd.com/read/29241827/prevalence-and-risk-factors-for-kidney-stones-in-fibrodysplasia-ossificans-progressiva
#13
REVIEW
Rishi R Gupta, Patricia L R Delai, David L Glaser, David M Rocke, Mona Al Mukaddam, Robert J Pignolo, Frederick S Kaplan
The worldwide prevalence and risk factors for kidney stones in patients with fibrodysplasia ossificans progressiva (FOP) are unknown. We conducted a survey of 383 patient-members of the International Fibrodysplasia Ossificans Progressiva Association, comprising the entire global membership of the international FOP community. Two hundred seven patients from 31 nations and 6 continents (54%) responded. Nineteen of 207 respondents had kidney stones, revealing a worldwide prevalence of 9.2%. In a confirmatory follow-up study of subjects participating in a longitudinal FOP natural history study, 9 of 114 individuals reported a history of kidney stones (7...
December 11, 2017: Bone
https://www.readbyqxmd.com/read/29241771/alopecia-areata-disease-characteristics-clinical-evaluation-and-new-perspectives-on-pathogenesis
#14
REVIEW
Lauren C Strazzulla, Eddy Hsi Chun Wang, Lorena Avila, Kristen Lo Sicco, Nooshin Brinster, Angela M Christiano, Jerry Shapiro
Alopecia areata (AA) is a common, inflammatory, nonscarring type of hair loss. Significant variations in the clinical presentation of AA have been observed, ranging from small, well-circumscribed patches of hair loss to a complete absence of body and scalp hair. Patients affected by AA encompass all age groups, sexes, and ethnicities, and may experience frustration with the unpredictable nature of their disease for which there is currently no definitive treatment. The cause of AA remains incompletely understood, though it is believed to result-at least in part-from a loss of immune privilege in the hair follicle, autoimmune-mediated hair follicle destruction, and the upregulation of inflammatory pathways...
January 2018: Journal of the American Academy of Dermatology
https://www.readbyqxmd.com/read/29241136/submillimeter-scale-heterogeneity-of-labile-phosphorus-in-sediments-characterized-by-diffusive-gradients-in-thin-films-and-spatial-analysis
#15
Yuting Meng, Shiming Ding, Mengdan Gong, Musong Chen, Yan Wang, Xianfang Fan, Lei Shi, Chaosheng Zhang
Sediments have a heterogeneous distribution of labile redox-sensitive elements due to a drastic downward transition from oxic to anoxic condition as a result of organic matter degradation. Characterization of the heterogeneous nature of sediments is vital for understanding of small-scale biogeochemical processes. However, there are limited reports on the related specialized methodology. In this study, the monthly distributions of labile phosphorus (P), a redox-sensitive limiting nutrient, were measured in the eutrophic Lake Taihu by Zr-oxide diffusive gradients in thin films (Zr-oxide DGT) on a two-dimensional (2D) submillimeter level...
December 5, 2017: Chemosphere
https://www.readbyqxmd.com/read/29241022/evolution-as-an-ecosystem-process-insights-from-genomics
#16
Blake Matthews, Rebecca J Best, Philine G D Feulner, Anita Narwani, Romana Limberger
Evolution is a fundamental ecosystem process. The study of genomic variation of organisms can not only improve our understanding of evolutionary processes, but also of contemporary and future ecosystem dynamics. We argue that integrative research between the fields of genomics and ecosystem ecology could generate new insights. Specifically, studies of biodiversity and ecosystem functioning, evolutionary rescue, and eco-evolutionary dynamics could all benefit from information about variation in genome structure and the genetic architecture of traits, whereas genomic studies could benefit from information about the ecological context of evolutionary dynamics...
December 14, 2017: Genome Génome / Conseil National de Recherches Canada
https://www.readbyqxmd.com/read/29240951/using-the-comet-assay-and-lysis-conditions-to-characterize-dna-lesions-from-the-acrylamide-metabolite-glycidamide
#17
Siri Helland Hansen, Agnieszka J Pawlowicz, Leif Kronberg, Kristine Bjerve Gützkow, Ann-Karin Olsen, Gunnar Brunborg
The alkaline comet assay and a cell-free system were used to characterise DNA lesions induced by treatment with glycidamide (GA), a metabolite of the food contaminant acrylamide. DNA lesions induced by GA were sensitively detected when the formamidopyrimidine-DNA-glycosylase (Fpg) enzyme was included in the comet assay. We used LC-MS to characterise modified bases from GA-treated naked DNA with and without subsequent Fpg treatment. N7-GA-Guanine and N3-GA-Adenine aglycons were detected in the supernatant showing some depurination of adducted bases; treatment of naked DNA with Fpg revealed no further increase in the adduct yield nor occurrence of other adducted nucleobases...
December 12, 2017: Mutagenesis
https://www.readbyqxmd.com/read/29240806/the-structure-of-salt-marsh-soil-mesofauna-food-webs-the-prevalence-of-disturbance
#18
Kristin Haynert, Mirijam Kiggen, Bernhard Klarner, Mark Maraun, Stefan Scheu
Mesofauna taxa fill key trophic positions in soil food webs, even in terrestrial-marine boundary habitats characterized by frequent natural disturbances. Salt marshes represent such boundary habitats, characterized by frequent inundations increasing from the terrestrial upper to the marine pioneer zone. Despite the high abundance of soil mesofauna in salt marshes and their important function by facilitating energy and carbon flows, the structure, trophic ecology and habitat-related diet shifts of mesofauna species in natural salt marsh habitats is virtually unknown...
2017: PloS One
https://www.readbyqxmd.com/read/29240790/single-cell-rna-sequencing-reveals-intrinsic-and-extrinsic-regulatory-heterogeneity-in-yeast-responding-to-stress
#19
Audrey P Gasch, Feiqiao Brian Yu, James Hose, Leah E Escalante, Mike Place, Rhonda Bacher, Jad Kanbar, Doina Ciobanu, Laura Sandor, Igor V Grigoriev, Christina Kendziorski, Stephen R Quake, Megan N McClean
From bacteria to humans, individual cells within isogenic populations can show significant variation in stress tolerance, but the nature of this heterogeneity is not clear. To investigate this, we used single-cell RNA sequencing to quantify transcript heterogeneity in single Saccharomyces cerevisiae cells treated with and without salt stress to explore population variation and identify cellular covariates that influence the stress-responsive transcriptome. Leveraging the extensive knowledge of yeast transcriptional regulation, we uncovered significant regulatory variation in individual yeast cells, both before and after stress...
December 14, 2017: PLoS Biology
https://www.readbyqxmd.com/read/29240764/selection-for-long-and-short-sleep-duration-in-drosophila-melanogaster-reveals-the-complex-genetic-network-underlying-natural-variation-in-sleep
#20
Susan T Harbison, Yazmin L Serrano Negron, Nancy F Hansen, Amanda S Lobell
Why do some individuals need more sleep than others? Forward mutagenesis screens in flies using engineered mutations have established a clear genetic component to sleep duration, revealing mutants that convey very long or short sleep. Whether such extreme long or short sleep could exist in natural populations was unknown. We applied artificial selection for high and low night sleep duration to an outbred population of Drosophila melanogaster for 13 generations. At the end of the selection procedure, night sleep duration diverged by 9...
December 2017: PLoS Genetics
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