Evidence for a nuclear compartment of transcription and splicing located at chromosome domain boundaries

The nuclear topography of splicing snRNPs, mRNA transcripts and chromosome domains in various mammalian cell types are described. The visualization of splicing snRNPs, defined by the Sm antigen, and coiled bodies, revealed distinctly different distribution patterns in these cell types. Heat shock experiments confirmed that the distribution patterns also depend on physiological parameters. Using a combination of fluorescencein situ hybridization and immunodetection protocols, individual chromosome domains were visualized simultaneously with the Sm antigen or the transcript of an integrated human papilloma virus genome. Three-dimensional analysis of fluorescence-stained target regions was performed by confocal laser scanning microscopy. RNA transcripts and components of the splicing machinery were found to be generally excluded from the interior of the territories occupied by the individual chromosomes. Based on these findings we present a model for the functional compartmentalization of the cell nucleus. According to this model the space between chromosome domains, including the surface areas of these domains, defines a three-dimensional network-like compartment, termed the interchromosome domain (ICD) compartment, in which transcription and splicing of mRNA occurs

Genome Profiling (GP) Method Based Classification of Insects: Congruence with That of Classical Phenotype-Based One

Ribosomal RNAs have been widely used for identification and classification of species, and have produced data giving new insights into phylogenetic relationships. Recently, multilocus genotyping and even whole genome sequencing-based technologies have been adopted in ambitious comparative biology studies. However, such technologies are still far from routine-use in species classification studies due to their high costs in terms of labor, equipment and consumables.Here, we describe a simple and powerful approach for species classification called genome profiling (GP). The GP method composed of random PCR, temperature gradient gel electrophoresis (TGGE) and computer-aided gel image processing is highly informative and less laborious. For demonstration, we classified 26 species of insects using GP and 18S rDNA-sequencing approaches. The GP method was found to give a better correspondence to the classical phenotype-based approach than did 18S rDNA sequencing employing a congruence value. To our surprise, use of a single probe in GP was sufficient to identify the relationships between the insect species, making this approach more straightforward.The data gathered here, together with those of previous studies show that GP is a simple and powerful method that can be applied for actually universally identifying and classifying species. The current success supported our previous proposal that GP-based web database can be constructible and effective for the global identification/classification of species

Genetic inhibition of neurotransmission reveals role of glutamatergic input to dopamine neurons in high-effort behavior

Midbrain dopamine neurons are crucial for many behavioral and cognitive functions. As the major excitatory input, glutamatergic afferents are important for control of the activity and plasticity of dopamine neurons. However, the role of glutamatergic input as a whole onto dopamine neurons remains unclear. Here we developed a mouse line in which glutamatergic inputs onto dopamine neurons are specifically impaired, and utilized this genetic model to directly test the role of glutamatergic inputs in dopamine-related functions. We found that while motor coordination and reward learning were largely unchanged, these animals showed prominent deficits in effort-related behavioral tasks. These results provide genetic evidence that glutamatergic transmission onto dopaminergic neurons underlies incentive motivation, a willingness to exert high levels of effort to obtain reinforcers, and have important implications for understanding the normal function of the midbrain dopamine system.Fil: Hutchison, M. A.. National Institutes of Health; Estados UnidosFil: Gu, X.. National Institutes of Health; Estados UnidosFil: Adrover, Martín Federico. National Institutes of Health; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Lee, M. R.. National Institutes of Health; Estados UnidosFil: Hnasko, T. S.. University of California at San Diego; Estados UnidosFil: Alvarez, V. A.. National Institutes of Health; Estados UnidosFil: Lu, W.. National Institutes of Health; Estados Unido

An Atomic-resolution nanomechanical mass sensor

Mechanical resonators are widely used as inertial balances to detect small quantities of adsorbed mass through shifts in oscillation frequency[1]. Advances in lithography and materials synthesis have enabled the fabrication of nanoscale mechanical resonators[2, 3, 4, 5, 6], which have been operated as precision force[7], position[8, 9] and mass sensors[10, 11, 12, 13, 14, 15]. Here we demonstrate a room-temperature, carbon-nanotube-based nanomechanical resonator with atomic mass resolution. This device is essentially a mass spectrometer with a mass sensitivity of 1.3 times 10^-25 kg Hz^-1/2 or, equivalently, 0.40 gold atoms Hz^-1/2. Using this extreme mass sensitivity, we observe atomic mass shot noise, which is analogous to the electronic shot noise[16, 17] measured in many semiconductor experiments. Unlike traditional mass spectrometers, nanomechanical mass spectrometers do not require the potentially destructive ionization of the test sample, are more sensitive to large molecules, and could eventually be incorporated on a chip

Dual Infection and Superinfection Inhibition of Epithelial Skin Cells by Two Alphaherpesviruses Co-Occur in the Natural Host

Hosts can be infected with multiple herpesviruses, known as superinfection; however, superinfection of cells is rare due to the phenomenon known as superinfection inhibition. It is believed that dual infection of cells occurs in nature, based on studies examining genetic exchange between homologous alphaherpesviruses in the host, but to date, this has not been directly shown in a natural model. In this report, gallid herpesvirus 2 (GaHV-2), better known as Marek’s disease virus (MDV), was used in its natural host, the chicken, to determine whether two homologous alphaherpesviruses can infect the same cells in vivo. MDV shares close similarities with the human alphaherpesvirus, varicella zoster virus (VZV), with respect to replication in the skin and exit from the host. Recombinant MDVs were generated that express either the enhanced GFP (eGFP) or monomeric RFP (mRFP) fused to the UL47 (VP13/14) herpesvirus tegument protein. These viruses exhibited no alteration in pathogenic potential and expressed abundant UL47-eGFP or -mRFP in feather follicle epithelial cells in vivo. Using laser scanning confocal microscopy, it was evident that these two similar, but distinguishable, viruses were able to replicate within the same cells of their natural host. Evidence of superinfection inhibition was also observed. These results have important implications for two reasons. First, these results show that during natural infection, both dual infection of cells and superinfection inhibition can co-occur at the cellular level. Secondly, vaccination against MDV with homologous alphaherpesvirus like attenuated GaHV-2, or non-oncogenic GaHV-3 or meleagrid herpesvirus (MeHV-1) has driven the virus to greater virulence and these results implicate the potential for genetic exchange between homologous avian alphaherpesviruses that could drive increased virulence. Because the live attenuated varicella vaccine is currently being administered to children, who in turn could be superinfected by wild-type VZV, this could potentiate recombination events of VZV as well

Swimming with Predators and Pesticides: How Environmental Stressors Affect the Thermal Physiology of Tadpoles

To forecast biological responses to changing environments, we need to understand how a species’s physiology varies through space and time and assess how changes in physiological function due to environmental changes may interact with phenotypic changes caused by other types of environmental variation. Amphibian larvae are well known for expressing environmentally induced phenotypes, but relatively little is known about how these responses might interact with changing temperatures and their thermal physiology. To address this question, we studied the thermal physiology of grey treefrog tadpoles (Hyla versicolor) by determining whether exposures to predator cues and an herbicide (Roundup) can alter their critical maximum temperature (CTmax) and their swimming speed across a range of temperatures, which provides estimates of optimal temperature (Topt) for swimming speed and the shape of the thermal performance curve (TPC). We discovered that predator cues induced a 0.4uC higher CTmax value, whereas the herbicide had no effect. Tadpoles exposed to predator cues or the herbicide swam faster than control tadpoles and the increase in burst speed was higher near Topt. In regard to the shape of the TPC, exposure to predator cues increased Topt by 1.5uC, while exposure to the herbicide marginally lowered Topt by 0.4uC. Combining predator cues and the herbicide produced an intermediate Topt that was 0.5uC higher than the control. To our knowledge this is the first study to demonstrate a predator altering the thermal physiology of amphibian larvae (prey) by increasing CTmax, increasing the optimum temperature, and producing changes in the thermal performance curves. Furthermore, these plastic responses of CTmax and TPC to different inducing environments should be considered when forecasting biological responses to global warming.Peer reviewe

Positioning pharmacists’ roles in primary health care: a discourse analysis of the compensation plan in Alberta, Canada

Abstract Background A comprehensive Compensation Plan for pharmacy services delivered by community pharmacists was implemented in Alberta, Canada in July 2012. Services covered by the Compensation Plan include care planning services, prescribing services such as adapting prescriptions, and administering a drug or publicly-funded vaccine by injection. Understanding how the Compensation Plan was framed and communicated provides insight into the roles of pharmacists and the potential influence of language on the implementation of services covered by the Compensation Plan by Albertan pharmacists. The objective of this study is to examine the positioning of pharmacists’ roles in documents used to communicate the Compensation Plan to Albertan pharmacists and other audiences. Methods Publicly available documents related to the Compensation Plan, such as news releases or reports, published between January 2012 and December 2015 were obtained from websites such as the Government of Alberta, Alberta Blue Cross, the Alberta College of Pharmacists, the Alberta Pharmacists’ Association, and the Blueprint for Pharmacy. Searches of the Canadian Newsstand database and Google identified additional documents. Discourse analysis was performed using social positioning theory to explore how pharmacists’ roles were constructed in communications about the Compensation Plan. Results In total, 65 publicly available documents were included in the analysis. The Compensation Plan was put forward as a framework for payment for professional services and formal legitimization of pharmacists’ changing professional roles. The discourse associated with the Compensation Plan positioned pharmacists’ roles as: (1) expanding to include services such as medication management for chronic diseases, (2) contributing to primary health care by providing access to services such as prescription renewals and immunizations, and (3) collaborating with other health care team members. Pharmacists’ changing roles were positioned in alignment with the aims of primary health care. Conclusions Social positioning theory provides a useful lens to examine the dynamic and evolving roles of pharmacists. This study provides insight into how communications regarding the Compensation Plan in Alberta, Canada positioned pharmacists’ changing roles in the broader context of changes to primary health care delivery. Our findings may be useful for other jurisdictions considering implementation of remunerated clinical services provided by pharmacists

A combined functional and structural genomics approach identified an EST-SSR marker with complete linkage to the Ligon lintless-2 genetic locus in cotton (Gossypium hirsutum L.)

<p>Abstract</p> <p>Background</p> <p>Cotton fiber length is an important quality attribute to the textile industry and longer fibers can be more efficiently spun into yarns to produce superior fabrics. There is typically a negative correlation between yield and fiber quality traits such as length. An understanding of the regulatory mechanisms controlling fiber length can potentially provide a valuable tool for cotton breeders to improve fiber length while maintaining high yields. The cotton (<it>Gossypium hirsutum </it>L.) fiber mutation Ligon lintless-2 is controlled by a single dominant gene (<it>Li₂</it>) that results in significantly shorter fibers than a wild-type. In a near-isogenic state with a wild-type cotton line, <it>Li₂</it>is a model system with which to study fiber elongation.</p> <p>Results</p> <p>Two near-isogenic lines of Ligon lintless-2 (<it>Li₂</it>) cotton, one mutant and one wild-type, were developed through five generations of backcrosses (BC₅). An F₂population was developed from a cross between the two <it>Li₂</it>near-isogenic lines and used to develop a linkage map of the <it>Li₂</it>locus on chromosome 18. Five simple sequence repeat (SSR) markers were closely mapped around the <it>Li₂</it>locus region with two of the markers flanking the <it>Li₂</it>locus at 0.87 and 0.52 centimorgan. No apparent differences in fiber initiation and early fiber elongation were observed between the mutant ovules and the wild-type ones. Gene expression profiling using microarrays suggested roles of reactive oxygen species (ROS) homeostasis and cytokinin regulation in the <it>Li₂</it>mutant phenotype. Microarray gene expression data led to successful identification of an EST-SSR marker (NAU3991) that displayed complete linkage to the <it>Li₂</it>locus.</p> <p>Conclusions</p> <p>In the field of cotton genomics, we report the first successful conversion of gene expression data into an SSR marker that is associated with a genomic region harboring a gene responsible for a fiber trait. The EST-derived SSR marker NAU3991 displayed complete linkage to the <it>Li₂</it>locus on chromosome 18 and resided in a gene with similarity to a putative plectin-related protein. The complete linkage suggests that this expressed sequence may be the <it>Li₂</it>gene.</p

At the bottom of the differential diagnosis list: unusual causes of pediatric hypertension

Hypertension affects 1–5% of children and adolescents, and the incidence has been increasing in association with obesity. However, secondary causes of hypertension such as renal parenchymal diseases, congenital abnormalities and renovascular disorders still remain the leading cause of pediatric hypertension, particularly in children under 12 years old. Other less common causes of hypertension in children and adolescents, including immobilization, burns, illicit and prescription drugs, dietary supplements, genetic disorders, and tumors will be addressed in this review