Read by QxMD icon Read

"Evolutionary mechanisms"

Kay Lucek
The evolution of intrinsic barriers to gene flow is a crucial step in the process of speciation. Chromosomal changes caused by fusion and fission events are one such barrier and are common in several groups of Lepidoptera. However, it remains unclear if and how chromosomal changes have contributed to speciation in this group. I tested for a phylogenetic signal of varying chromosome numbers in Erebia butterflies by combining existing sequence data with karyological information. I also compared different models of trait evolution in order to infer the underlying evolutionary mechanisms...
March 16, 2018: Genes
José F Muñoz, Juan G McEwen, Oliver K Clay, Christina A Cuomo
Dimorphic fungal pathogens cause a significant human disease burden and unlike most fungal pathogens affect immunocompetent hosts. To examine the origin of virulence of these fungal pathogens, we compared genomes of classic systemic, opportunistic, and non-pathogenic species, including Emmonsia and two basal branching, non-pathogenic species in the Ajellomycetaceae, Helicocarpus griseus and Polytolypa hystricis. We found that gene families related to plant degradation, secondary metabolites synthesis, and amino acid and lipid metabolism are retained in H...
March 14, 2018: Scientific Reports
Wen-Yong Guo, Carla Lambertini, Petr Pyšek, Laura A Meyerson, Hans Brix
Identifying the factors that influence spatial genetic structure among populations can provide insights into the evolution of invasive plants. In this study, we used the common reed ( Phragmites australis ), a grass native in Europe and invading North America, to examine the relative importance of geographic, environmental (represented by climate here), and human effects on population genetic structure and its changes during invasion. We collected samples of P. australis from both the invaded North American and native European ranges and used molecular markers to investigate the population genetic structure within and between ranges...
March 2018: Ecology and Evolution
Lewis M Ward, James Hemp, Patrick M Shih, Shawn E McGlynn, Woodward W Fischer
The evolutionary mechanisms behind the extant distribution of photosynthesis is a point of substantial contention. Hypotheses range from the presence of phototrophy in the last universal common ancestor and massive gene loss in most lineages, to a later origin in Cyanobacteria followed by extensive horizontal gene transfer into the extant phototrophic clades, with intermediate scenarios that incorporate aspects of both end-members. Here, we report draft genomes of 11 Chloroflexi: the phototrophic Chloroflexia isolate Kouleothrix aurantiaca as well as 10 genome bins recovered from metagenomic sequencing of microbial mats found in Japanese hot springs...
2018: Frontiers in Microbiology
T C Goldsmith
Programmed aging theories contend that evolved biological mechanisms purposely limit internally determined lifespans in mammals and are ultimately responsible for most instances of highly age-related diseases and conditions. Until recently, the existence of programmed aging mechanisms was considered theoretically impossible because it directly conflicted with Darwin's survival-of-the-fittest evolutionary mechanics concept as widely taught and generally understood. However, subsequent discoveries, especially in genetics, have exposed issues with some details of Darwin's theory that affect the mechanics of the evolution process and strongly suggest that programmed aging mechanisms in humans and other mammals can and did evolve, and more generally, that a trait that benefits a population can evolve even if, like senescence, it is adverse to individual members of the population...
December 2017: Biochemistry. Biokhimii︠a︡
Joël R Federer-Gsponer, Cristina Quintavalle, David C Müller, Tanja Dietsche, Valeria Perrina, Thomas Lorber, Darius Juskevicius, Elisabeth Lenkiewicz, Tobias Zellweger, Thomas Gasser, Michael T Barrett, Cyrill A Rentsch, Lukas Bubendorf, Christian Ruiz
Understanding the evolutionary mechanisms and genomic events leading to castration resistant (CR) prostate cancer (PC) is key to improve the outcome of this otherwise deadly disease. Here, we delineated the tumour history of seven patients progressing to castration resistance by analysing matched prostate cancer tissues before and after castration. We performed genomic profiling of DNA-content based flow-sorted populations in order to define the different evolutionary patterns. In one patient, we discovered that a catastrophic genomic event, known as chromothripsis, resulted in multiple CRPC tumour populations with distinct, potentially advantageous copy number aberrations, including an amplification of FK506 Binding Protein 4 (FKBP4, also known as FKBP52), a protein enhancing the transcriptional activity of androgen receptor signalling...
February 27, 2018: Journal of Pathology
Dan Sun, Iksoo Huh, Wendy M Zinzow-Kramer, Donna L Maney, Soojin V Yi
In the white-throated sparrow ( Zonotrichia albicollis ), the second chromosome bears a striking resemblance to sex chromosomes. First, within each breeding pair of birds, one bird is homozygous for the standard arrangement of the chromosome (ZAL2/ZAL2) and its mate is heterozygous for a different version (ZAL2/ZAL2m ). Second, recombination is profoundly suppressed between the two versions, leading to genetic differentiation between them. Third, the ZAL2m version is linked with phenotypic traits, such as bright plumage, high aggression, and low parental behavior, which are usually associated with males...
February 26, 2018: Proceedings of the National Academy of Sciences of the United States of America
Carmel Mothersill, Richard Smith, Jiaxi Wang, Andrej Rusin, Cris Fernandez-Palomo, Jennifer Fazzari, Colin Seymour
The phenomenon by which irradiated organisms including cells in vitro communicate with unirradiated neighbors is well established in biology as the radiation-induced bystander effect (RIBE). Generally, the purpose of this communication is thought to be protective and adaptive, reflecting a highly conserved evolutionary mechanism enabling rapid adjustment to stressors in the environment. Stressors known to induce the effect were recently shown to include chemicals and even pathological agents. The mechanism is unknown but our group has evidence that physical signals such as biophotons acting on cellular photoreceptors may be implicated...
January 2018: Dose-response: a Publication of International Hormesis Society
Aneth S Canale, Sergey V Venev, Troy W Whitfield, Daniel R Caffrey, Wayne A Marasco, Celia A Schiffer, Timothy F Kowalik, Jeffrey D Jensen, Robert W Finberg, Konstantin B Zeldovich, Jennifer P Wang, Daniel N A Bolon
The fitness effects of synonymous mutations can provide insights into biological and evolutionary mechanisms. We analyzed the experimental fitness effects of all single nucleotide mutations, including synonymous substitutions, at the beginning of the influenza A virus hemagglutinin (HA) gene. Many synonymous substitutions were deleterious in both bulk competition and for individually isolated clones. Investigating protein and RNA levels of a subset of individually expressed HA variants revealed that multiple biochemical properties contribute to the observed experimental fitness effects...
February 18, 2018: Journal of Molecular Biology
Pavel V Mazin, Elena Shagimardanova, Olga Kozlova, Alexander Cherkasov, Roman Sutormin, Vita V Stepanova, Alexey Stupnikov, Maria Logacheva, Aleksey Penin, Yoichiro Sogame, Richard Cornette, Shoko Tokumoto, Yugo Miyata, Takahiro Kikawada, Mikhail S Gelfand, Oleg Gusev
Polypedilum vanderplanki is a striking and unique example of an insect that can survive almost complete desiccation. Its genome and a set of dehydration-rehydration transcriptomes, together with the genome of Polypedilum nubifer (a congeneric desiccation-sensitive midge), were recently released. Here, using published and newly generated datasets reflecting detailed transcriptome changes during anhydrobiosis, as well as a developmental series, we show that the TCTAGAA DNA motif, which closely resembles the binding motif of the Drosophila melanogaster heat shock transcription activator (Hsf), is significantly enriched in the promoter regions of desiccation-induced genes in P...
February 20, 2018: Proceedings of the National Academy of Sciences of the United States of America
Josiah T Wagner, Param Priya Singh, Amie L Romney, Claire L Riggs, Patrick Minx, Steven C Woll, Jake Roush, Wesley C Warren, Anne Brunet, Jason E Podrabsky
BACKGROUND: The annual killifish Austrofundulus limnaeus inhabits ephemeral ponds in northern Venezuela, South America, and is an emerging extremophile model for vertebrate diapause, stress tolerance, and evolution. Embryos of A. limnaeus regularly experience extended periods of desiccation and anoxia as a part of their natural history and have unique metabolic and developmental adaptations. Currently, there are limited genomic resources available for gene expression and evolutionary studies that can take advantage of A...
February 20, 2018: BMC Genomics
Ahmed S Abdel-Moneim, May S Soliman, Mahmoud M Kamel, Amani A El-Kholy
Human respiratory syncytial virus causes severe lower respiratory tract infection in neonates and children. Genotype ON1, with duplication of 72-nt in the G gene, was first detected in Canada and then recorded in other countries. In the current study, we describe the first detection of the ON1 genotype among children in Egypt in 2014/2015. Sequence analysis of the full-attachment G gene revealed that the majority of the strains examined were related to the ON1 genotype and only one sample related to N1 genotype...
February 2, 2018: Journal of Medical Microbiology
Marieke E Feis, Uwe John, Ana Lokmer, Pieternella C Luttikhuizen, K Mathias Wegner
On theoretical grounds, antagonistic co-evolution between hosts and their parasites should be a widespread phenomenon but only received little empirical support so far. Consequently, the underlying molecular mechanisms and evolutionary steps remain elusive, especially in non-model systems. Here, we utilised the natural history of invasive parasites to document the molecular underpinnings of co-evolutionary trajectories. We applied a dual-species transcriptomics approach to experimental cross-infections of blue mussel Mytilus edulis hosts and their invasive parasitic copepods Mytilicola intestinalis from two invasion fronts in the Wadden Sea...
February 17, 2018: Molecular Ecology
Arjun K Mishra, Roy A Mariuzza
Affinity maturation is the process whereby the immune system generates antibodies of higher affinities during a response to antigen. It is unique in being the only evolutionary mechanism known to operate on a molecule in an organism's own body. Deciphering the structural mechanisms through which somatic mutations in antibody genes increase affinity is critical to understanding the evolution of immune repertoires. Next-generation sequencing (NGS) has allowed the reconstruction of antibody clonal lineages in response to viral pathogens, such as HIV-1, which was not possible in earlier studies of affinity maturation...
2018: Frontiers in Immunology
Paulo Durão, Roberto Balbontín, Isabel Gordo
Antibiotics target essential cellular functions but bacteria can become resistant by acquiring either exogenous resistance genes or chromosomal mutations. Resistance mutations typically occur in genes encoding essential functions; these mutations are therefore generally detrimental in the absence of drugs. However, bacteria can reduce this handicap by acquiring additional mutations, known as compensatory mutations. Genetic interactions (epistasis) either with the background or between resistances (in multiresistant bacteria) dramatically affect the fitness cost of antibiotic resistance and its compensation, therefore shaping dissemination of antibiotic resistance mutations...
February 10, 2018: Trends in Microbiology
Hai-Ming Zhao, He-Biao Huang, Huan Du, Jing Lin, Lei Xiang, Yan-Wen Li, Quan-Ying Cai, Hui Li, Ce-Hui Mo, Jie-Sheng Liu, Ming-Hung Wong, Dong-Mei Zhou
To investigate the mechanism of genotype differences in ciprofloxacin (CIP) accumulation, this study was designed to compare the tolerance and metabolic responses to CIP exposure between low (Cutai) and high (Sijiu) CIP-accumulation cultivars of Brassica parachinensis. Decreases in biomass and chlorophyll content were significantly greater (p < 0.05) and toxicities were more severe within cell ultrastructures of Cutai compared to Sijiu. A sequential growth test also revealed that Sijiu was more tolerant to CIP stress compared to Cutai...
January 9, 2018: Journal of Hazardous Materials
Esmaeil Behmard, Ali Najafi, Ali Ahmadi
Antibiotic resistance is a threatening challenge for global health, as the expansion of resistance to current antibiotics has made serious therapeutic problems. Genome mutations are key evolutionary mechanisms conferring antibiotic resistance in bacterial pathogens. For example, penicillin and cephalosporins resistance is mostly mediated by mutations in penicillin binding proteins to change the affinity of the drug. Accordingly, threonine point mutations were reported to develop antibiotic resistance in various bacterial infections including pneumococcal infections...
February 11, 2018: Journal of Biomolecular Structure & Dynamics
Lotus Lofgren, Nhu H Nguyen, Peter G Kennedy
Despite the importance of ectomycorrhizal (ECM) fungi in forest ecosystems, knowledge about the ecological and co-evolutionary mechanisms underlying ECM host associations remains limited. Using a widely distributed group of ECM fungi known to form tight associations with trees in the family Pinaceae, we characterized host specificity among three unique Suillus-host species pairs using a combination of field root tip sampling and experimental bioassays. We demonstrate that the ECM fungus S. subaureus can successfully colonize Quercus hosts in both field and glasshouse settings, making this species unique in an otherwise Pinaceae-specific clade...
February 7, 2018: New Phytologist
Jacobo Reyes-Velasco, Joseph D Manthey, Yann Bourgeois, Xenia Freilich, Stéphane Boissinot
Understanding the diversification of biological lineages is central to evolutionary studies. To properly study the process of speciation, it is necessary to link micro-evolutionary studies with macro-evolutionary mechanisms. Micro-evolutionary studies require proper sampling across a taxon's range to adequately infer genetic diversity. Here we use the grass frogs of the genus Ptychadena from the Ethiopian highlands as a model to study the process of lineage diversification in this unique biodiversity hotspot...
2018: PloS One
Orr Levy, Isak Nethanël Gath
We investigate the spread from ancestors to descendants, under a model of sexual reproduction, of hereditary elements distinguishing individuals from their fellow human beings. These hereditary elements, termed labels, are either symbolic, implying a socio-cultural or ethnic self-determined category, or biological, i.e. a DNA sequence (for example founder mutations). The impact of various modes of preferential (assortative) mating on the dissemination of a known ancestral label was studied for both kinds of labels, the symbolic and the biological...
January 27, 2018: Journal of Theoretical Biology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"