Read by QxMD icon Read


Anna Hegsted, Forrest A Wright, SarahBeth Votra, David Pruyne
Formins are regulators of actin filament dynamics. We demonstrate here that two formins, FHOD-1 and EXC-6, are important in the nematode Caenorhabditis elegans for ovulation, during which actomyosin contractions push a maturing oocyte from the gonad arm into a distensible bag-like organ, the spermatheca. EXC-6, a homolog of the disease-associated mammalian formin INF2, is highly expressed in the spermatheca, where it localizes to cell-cell junctions and to circumferential actin filament bundles. Loss of EXC-6 does not noticeably affect the organization the actin filament bundles, and causes only a very modest increase in the population of junction-associated actin filaments...
October 22, 2016: Cytoskeleton
Sangmi Oh, Ichiro Kawasaki, Jae-Hyung Park, Yhong-Hee Shim
Cell division cycle 25 (cdc25) is an evolutionarily conserved phosphatase that promotes cell cycle progression. Among the four cdc25 orthologs in Caenorhabditis elegans, we found that cdc-25.4 mutant males failed to produce outcrossed progeny. This was not caused by defects in sperm development, but by defects in male mating behavior. The cdc-25.4 mutant males showed various defects during male mating, including contact response, backing, turning, and vulva location. Aberrant turning behavior was the most prominent defect in the cdc-25...
October 21, 2016: G3: Genes—Genomes—Genetics
Lingfeng Meng, Albert Zhang, Yishi Jin, Dong Yan
Axon specification is a critical step in neuronal development, and the function of glial cells in this process is not fully understood. Here we show that C. elegans GLR glial cells regulate axon specification of their nearby GABAergic RME neurons through GLR-RME gap junctions. Disruption of GLR-RME gap junctions causes misaccumulation of axonal markers in non-axonal neurites of RME neurons and converts microtubules in those neurites to form an axon-like assembly. We further uncover that GLR-RME gap junctions regulate RME axon specification through activation of the CDK-5 pathway in a calcium-dependent manner, involving a calpain clp-4...
October 21, 2016: ELife
Young Joon Kwon, Marni J Falk, Michael J Bennett
CLN3 disease (Spielmeyer-Vogt-Sjogren-Batten disease, previously known as classic juvenile neuronal ceroid lipofuscinosis, NCL) is a pediatric-onset progressive neurodegenerative disease characterized by progressive vision loss, seizures, loss of cognitive and motor function, and early death. While no precise biochemical mechanism or therapies are known, the pathogenesis of CLN3 disease involves intracellular calcium accumulation that may trigger apoptosis. Our prior work in in vitro cell models of CLN3 deficiency suggested that FDA-approved calcium channel antagonists may have therapeutic value...
October 20, 2016: Journal of Inherited Metabolic Disease
Shaul Yogev, Roshni Cooper, Richard Fetter, Mark Horowitz, Kang Shen
Axonal microtubule (MT) arrays are the major cytoskeleton substrate for cargo transport. How MT organization, i.e., polymer length, number, and minus-end spacing, is regulated and how it impinges on axonal transport are unclear. We describe a method for analyzing neuronal MT organization using light microscopy. This method circumvents the need for electron microscopy reconstructions and is compatible with live imaging of cargo transport and MT dynamics. Examination of a C. elegans motor neuron revealed how age, MT-associated proteins, and signaling pathways control MT length, minus-end spacing, and coverage...
October 19, 2016: Neuron
Emily R Troemel
Microsporidia comprise a phylum of obligate intracellular pathogens related to fungi that infect virtually all animals. Recently, the nematode Caenorhabditis elegans has been developed as a convenient model for studying microsporidia infection in a whole-animal host through the identification and characterization of a natural microsporidian pathogen of this commonly studied laboratory organism. The C. elegans natural microsporidian pathogen is named Nematocida parisii, and it causes a lethal intestinal infection in C...
October 2016: Microbiology Spectrum
Mi-Sun Kwon, Jaewon Min, Hee-Yeon Jeon, Kwangwoo Hwang, Chuna Kim, Junho Lee, Je-Gun Joung, Woong-Yang Park, Hyunsook Lee
BRCA2 is a multifunctional tumor suppressor involved in homologous recombination (HR), mitotic checkpoint regulation, and telomere homeostasis. Absence of Brca2 in mice results in progressive shortening of telomeres and senescence, yet cells are prone to neoplastic transformation with elongated telomeres, suggesting that BRCA2 has positive and negative effects on telomere length regulation along the path to tumorigenesis. Using Caenorhabditis elegans as a model, we show here that depletion of BRC-2, an ortholog of BRCA2, paradoxically delays senescence in telomerase-deficient mutant worms...
October 2016: FEBS Open Bio
Cristina Matthewman, Tyne W Miller-Fleming, David M Miller, Laura Bianchi
Hyperactivated DEG/ENaC channels cause neuronal death mediated by intracellular Ca(2+) overload. Mammalian ASIC1a and C. elegans MEC-4(d) neurotoxic channels conduct both Na(+) and Ca(2+) raising the possibility that direct Ca(2+) influx through these channels contributes to the intracellular Ca(2+) overload. However, we showed that homologous C. elegans DEG/ENaC channel UNC-8(d) is not Ca(2+) permeable yet it is neurotoxic, suggesting that Na(+) influx is sufficient to induce cell death. Interestingly, UNC-8(d) shows small currents due to extracellular Ca(2+) block in the Xenopus oocytes expression system...
October 19, 2016: American Journal of Physiology. Cell Physiology
Jacques Pécréaux, Stefanie Redemann, Zahraa Alayan, Benjamin Mercat, Sylvain Pastezeur, Carlos Garzon-Coral, Anthony A Hyman, Jonathon Howard
Precise positioning of the mitotic spindle is important for specifying the plane of cell division, which in turn determines how the cytoplasmic contents of the mother cell are partitioned into the daughter cells, and how the daughters are positioned within the tissue. During metaphase in the early Caenorhabditis elegans embryo, the spindle is aligned and centered on the anterior-posterior axis by a microtubule-dependent machinery that exerts restoring forces when the spindle is displaced from the center. To investigate the accuracy and stability of centering, we tracked the position and orientation of the mitotic spindle during the first cell division with high temporal and spatial resolution...
October 18, 2016: Biophysical Journal
Antonia Piazzesi, Dražen Papić, Fabio Bertan, Paolo Salomoni, Pierluigi Nicotera, Daniele Bano
Chromatin structure orchestrates the accessibility to the genetic material. Replication-independent histone variants control transcriptional plasticity in postmitotic cells. The life-long accumulation of these histones has been described, yet the implications on organismal aging remain elusive. Here, we study the importance of the histone variant H3.3 in Caenorhabditis elegans longevity pathways. We show that H3.3-deficient nematodes have negligible lifespan differences compared to wild-type animals. However, H3...
October 18, 2016: Cell Reports
Daifeng Wang, Fei He, Sergei Maslov, Mark Gerstein
Gene expression is controlled by the combinatorial effects of regulatory factors from different biological subsystems such as general transcription factors (TFs), cellular growth factors and microRNAs. A subsystem's gene expression may be controlled by its internal regulatory factors, exclusively, or by external subsystems, or by both. It is thus useful to distinguish the degree to which a subsystem is regulated internally or externally-e.g., how non-conserved, species-specific TFs affect the expression of conserved, cross-species genes during evolution...
October 2016: PLoS Computational Biology
Juan Antonio Garcia-Martin, Amir H Bayegan, Ivan Dotu, Peter Clote
BACKGROUND: RNA inverse folding is the problem of finding one or more sequences that fold into a user-specified target structure s 0, i.e. whose minimum free energy secondary structure is identical to the target s 0. Here we consider the ensemble of all RNA sequences that have low free energy with respect to a given target s 0. RESULTS: We introduce the program RNAdualPF, which computes the dual partition function Z (∗), defined as the sum of Boltzmann factors exp(-E(a,s 0)/RT) of all RNA nucleotide sequences a compatible with target structure s 0...
October 19, 2016: BMC Bioinformatics
Mark D Mathew, Neal D Mathew, Angela Miller, Mike Simpson, Vinci Au, Stephanie Garland, Marie Gestin, Mark L Edgley, Stephane Flibotte, Aruna Balgi, Jennifer Chiang, Guri Giaever, Pamela Dean, Audrey Tung, Michel Roberge, Calvin Roskelley, Tom Forge, Corey Nislow, Donald Moerman
BACKGROUND: The lack of new anthelmintic agents is of growing concern because it affects human health and our food supply, as both livestock and plants are affected. Two principal factors contribute to this problem. First, nematode resistance to anthelmintic drugs is increasing worldwide and second, many effective nematicides pose environmental hazards. In this paper we address this problem by deploying a high throughput screening platform for anthelmintic drug discovery using the nematode Caenorhabditis elegans as a surrogate for infectious nematodes...
October 2016: PLoS Neglected Tropical Diseases
Robin van Schendel, Jane van Heteren, Richard Welten, Marcel Tijsterman
For more than half a century, genotoxic agents have been used to induce mutations in the genome of model organisms to establish genotype-phenotype relationships. While inaccurate replication across damaged bases can explain the formation of single nucleotide variants, it remained unknown how DNA damage induces more severe genomic alterations. Here, we demonstrate for two of the most widely used mutagens, i.e. ethyl methanesulfonate (EMS) and photo-activated trimethylpsoralen (UV/TMP), that deletion mutagenesis is the result of polymerase Theta (POLQ)-mediated end joining (TMEJ) of double strand breaks (DSBs)...
October 2016: PLoS Genetics
Asad Jan, Brandon Jansonius, Alberto Delaidelli, Syam Prakash Somasekharan, Forum Bhanshali, Milène Vandal, Gian Luca Negri, Don Moerman, Ian MacKenzie, Frédéric Calon, Michael R Hayden, Stefan Taubert, Poul H Sorensen
Soluble oligomers of amyloid-β (Aβ) impair synaptic plasticity, perturb neuronal energy homeostasis, and are implicated in Alzheimer's disease (AD) pathogenesis. Therefore, significant efforts in AD drug discovery research aim to prevent the formation of Aβ oligomers or block their neurotoxicity. The eukaryotic elongation factor-2 kinase (eEF2K) plays a critical role in synaptic plasticity, and couples neurotransmission to local dendritic mRNA translation. Recent evidence indicates that Aβ oligomers activate neuronal eEF2K, suggesting a potential link to Aβ induced synaptic dysfunction...
October 17, 2016: Acta Neuropathologica
Carmen Jiménez-Castells, Jorick Vanbeselaere, Sonja Kohlhuber, Bärbel Ruttkowski, Anja Joachim, Katharina Paschinger
BACKGROUND: The porcine nodule worm Oesophagostomum dentatum is a strongylid class V nematode rather closely related to the model organism Caenorhabditis elegans. However, in contrast to the non-parasitic C. elegans, the parasitic O. dentatum is an obligate sexual organism, which makes both a gender and developmental glycomic comparison possible. METHODS: Different enzymatic and chemical methods were used to release N-glycans from male and female O. dentatum as well as from L3 and L4 larvae...
October 15, 2016: Biochimica et Biophysica Acta
Janis C Weeks, William M Roberts, Kristin J Robinson, Melissa Keaney, Jon J Vermeire, Joseph F Urban, Shawn R Lockery, John M Hawdon
The screening of candidate compounds and natural products for anthelmintic activity is important for discovering new drugs against human and animal parasites. We previously validated in Caenorhabditis elegans a microfluidic device ('chip') that records non-invasively the tiny electrophysiological signals generated by rhythmic contraction (pumping) of the worm's pharynx. These electropharyngeograms (EPGs) are recorded simultaneously from multiple worms per chip, providing a medium-throughput readout of muscular and neural activity that is especially useful for compounds targeting neurotransmitter receptors and ion channels...
September 15, 2016: International Journal for Parasitology, Drugs and Drug Resistance
Aida Costa, Lynn M Powell, Sally Lowell, Andrew P Jarman
The proneural gene, Atoh1, is necessary and in some contexts sufficient for early inner ear hair cell development. Its function is the subject of intensive research, not least because of the possibility that it could be used in therapeutic strategies to reverse hair cell loss in deafness. However, it is clear that Atoh1's function is highly context dependent. During inner ear development, Atoh1 is only able to promote hair cell differentiation at specific developmental stages. Outside the ear, Atoh1 is required for differentiation of a variety of other cell types, for example in the intestine and cerebellum...
October 14, 2016: Seminars in Cell & Developmental Biology
Lu Kong, Xiaojie Gao, Jiaqian Zhu, Ting Zhang, Yuying Xue, Meng Tang
To investigate the reproductive toxicity and underlying mechanism of nickel nanoparticles (Ni NPs), Caenorhabditis elegans (C. elegans) were treated with/without 1.0, 2.5, and 5.0 μg cm(-2) of Ni NPs or nickel microparticles (Ni MPs). Generation time, fertilized egg numbers, spermatide activation and motility were detected. Results indicated, under the same treatment doses, that Ni NPs induced higher reproductive toxicity to C. elegans than Ni MPs. Reproductive toxicities observed in C. elegans included a decrease in brood size, fertilized egg and spermatide activation, but an increase in generation time and out-of-round spermatids...
October 17, 2016: Environmental Toxicology
Yan Xu, Christopher C Quinn
Axonal branch formation and synaptogenesis are sequential events that are required for the establishment of neuronal connectivity. However, little is known about how the transition between these two events is regulated. Here, we report that the lin-4 microRNA can regulate the transition between branch formation and synaptogenesis in the PLM axon of C. elegans. The PLM axon grows a collateral branch during the early L1 stage and undergoes synaptogenesis during the late L1 stage. Loss of the lin-4 microRNA disrupts synaptogenesis during the late L1 stage, suggesting that lin-4 promotes synaptogenesis...
October 13, 2016: Developmental 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"