IR Laser-Induced Gene Expression for Tracking Development of Single Embryonic Neurons and Glia in C. Elegans

The assembly of neural circuits requires a complex choreography of developmental events: neurons must be generated, extend neurites at the correct time and location, and then integrate extracellular information, like long-range guidance cues or cellular contacts, with an internal developmental program to make correct wiring decisions. Visualizing neural-circuit assembly in vivo can provide insight into how these events are coordinated. The C. elegans embryo, which contains only 222 neurons and 56 glia, is an attractive setting to study nervous system development comprehensively in an intact, living organism. However, methods to label and track optically-resolvable neurites or manipulate single neurons through gene expression do not exist, as most embryonic reporters are broadly expressed. Here, I present a method for expressing fluorescent reporters or any gene of interest in specific C. elegans embryonic neurons, glia, or other cell types, without cell specific drivers. Our method is based on a previous setup (Kamei et al., 2009), and uses an infrared (IR) laser to localize heat to the volume of a single precursor cell in the embryo. This induces gene expression in the progeny of that cell (1-4 cells/embryo) through heat-shock-response regulatory elements. I perform significant optimizations to adapt this strategy to cells in the C. elegans embryo, which are highly sensitive to heat toxicity. Direct temperature measurements of IR heating in the embryo reveal that cells are heated to physiological temperatures (320C) for 5 minute durations using our modified irradiation protocol. These conditions lead to high rates of gene induction (\u3e60%) with no signs of damage. First, I use our system to label and track single neurons during early nervous system assembly. These studies reveal a retrograde extension mechanism for axon growth in specific interneurons. I also study the etiology of axon-guidance defects in sax-3/Robo and vab-1/EphR mutants; these studies suggest that a timing/competence mechanism controls axon-outgrowth dynamics in the nerve ring. Next, I demonstrate the versatility of IR irradiation by performing cell-specific rescues, determining DAF-6/Patched-related site of action during sensory-organ development. Finally, I demonstrate that IR cell irradiation can be used to perform simultaneous ablation and labeling of cells in the same embryo. I use this system to uncover a role for the amphid sheath glia in dendrite extension. As IR induction can be used for targeted labeling, gene expression, and ablation without the need for cell-specific drivers, this tool opens to door to high resolution systematic analyses of C. elegans morphogenesis

Environment: Towards Community & Market Management

The Department of Environment is engaged in overall environmental assessment, monitoring, protection and raising awareness among the people of Delhi. The Delhi Pollution Control Committee (DPCC) is responsible for environmental monitoring and implementation of various pollution control acts and rules, which will be discussed in this paper.[Working Paper No. 0077]Department, Environment,environmental assessment,protection, raising awareness, Delhi Pollution Control Committee,environmental monitoring, implementation

State in Religion: Preamble to Pogrom

India is a secular state in which all faiths enjoy freedom of worship. The concept of secularism is implicit in the Preamble to our Constitution, which declares the resolve of the people to secure to all its citizens “liberty of thought, belief, faith, and worship.” There is no mysticism in the secular character of the state. Secularism is neither anti-god nor pro-god, it treats alike the devout, the agnostic, and the atheist. It eliminates god from the matters of the state and ensures that no one shall be discriminated against on the ground of religion. The state can have no religion of its own. It should treat all religions equally. In a secular state, the state is only concerned with the relation between man and man. It is not concerned with the relationship of man with god. It is left to the individual’s conscience. Man is not answerable to the state for any of his religious views. There can be no compulsions in law for any creed or practice of any form of worship.1 Since time immemorial, institutionalised religion has been “oppressive” and a tool in the hands of a few power-wielding people and it is no different in the contemporary scenario. [Working Paper No. 0037]liberty of thought, belief, faith, worship,Secularism, freedom of worship, Preamble,Constitution

Big Industry Before Independence: 1860-1950

The world over, in the eighteenth and nineteenth centuries, private sector units were of a laissez-faire variety i.e., the private sector was completely free of state interference. Private enterprises were units owned and managed by individual proprietors and partnerships. Even in India, private business houses in spite of many obstructions placed by the British government flourished and managed to earn huge profits. This was also the era when government investment in industry was zero. Thus, in this paper we try to analyse the rationale behind government investment in industry post independence. At the beginning of the First World War, Europeans managing agency houses enjoyed unchallenged supremacy in the private corporate sector of the Indian economy. At the end of the Second World War this supremacy had been broken and Indian entrepreneurs, advancing by rapid strides in the inter-war period, were now in a position to take over the business of the departing British. [Working Paper No. 0025]eigtheenth, nineteenth centuries, private sector units, British Government, unchallenged supremacy,Indian Entrepreneurs, second world war

Glutamate spillover in C. elegans triggers repetitive behavior through presynaptic activation of MGL-2/mGluR5

International audienceGlutamate is a major excitatory neurotransmitter, and impaired glutamate clearance following synaptic release promotes spillover, inducing extra-synaptic signaling. The effects of glutamate spillover on animal behavior and its neural correlates are poorly understood. We developed a glutamate spillover model in Caenorhabditis elegans by inactivating the conserved glial glutamate transporter GLT-1. GLT-1 loss drives aberrant repetitive locomotory reversal behavior through uncontrolled oscillatory release of glutamate onto AVA, a major inter-neuron governing reversals. Repetitive glutamate release and reversal behavior require the glutamate receptor MGL-2/mGluR5, expressed in RIM and other interneurons presynaptic to AVA. mgl-2 loss blocks oscillations and repetitive behavior; while RIM activation is sufficient to induce repetitive reversals in glt-1 mutants. Repetitive AVA firing and reversals require EGL-30/Gαq, an mGluR5 effector. Our studies reveal that cyclic autocrine presynaptic activation drives repetitive reversals following glutamate spillover. That mammalian GLT1 and mGluR5 are implicated in pathological motor repetition suggests a common mechanism controlling repetitive behaviors

Supplementary Table 6 from Alveolar Differentiation Drives Resistance to <i>KRAS</i> Inhibition in Lung Adenocarcinoma

Supplementary Table 6 shows the TotalSeqB hashtag oligonucleotide-conjugated antibodies.</p

Supplementary Table 5 from Alveolar Differentiation Drives Resistance to <i>KRAS</i> Inhibition in Lung Adenocarcinoma

Supplementary Table 5 shows the primers used in this study.</p

Supplementary Table 3 from Alveolar Differentiation Drives Resistance to <i>KRAS</i> Inhibition in Lung Adenocarcinoma

Supplementary Table 3 shows mouse AT1-like LUAD signature genes.</p