Our research team will investigate how pathogenic bacteria use molecular pumps as part of a mechanism to evade antibacterial drugs. When the drugs enter the bacteria, they can be rapidly expelled again by the action of molecular pumps, before the drugs have an opportunity to harm the organism. The pumps we will study are composed of three different types of proteins, two of which span the protective bacterial membrane, and the third helps to draw the other two together into a functional unit. It is not presently understood how these components of the pump assemble together to make a functioning unit, and how the unit works to recognise and displace the drug to the outside of the cell. The team will attempt to elucidate the three dimensional structure of representative molecular pumps to address these questions. The team will examine how the components interact and how the pump uses energy to displace drugs from the interior of the bacterium out into the medium. We will also examine how the components come together to form a functioning unit in a living bacterium. The information obtained from this work may help us to understand how to combat the growing problem of multidrug resistance in bacterial infections.

My overarching goal is to identify the defined set of factors that can rejuvenate an aged cell. Several lines of evidence indicate this might be possible (e.g. by manipulation of signaling pathways, reactivation of embryonic genes etc’); however, in most cases, the rejuvenation process is either incomplete or increases the risk of cancer. My idea is to adopt some of the concepts of reprogramming toward rejuvenation and to identify the set of factors that can efficiently rejuvenate aged cells, without de-differentiation or increased risk of malignant transformation.

Neural stem cells (NSCs) represent a paradigm for adult stem cells and provide an ideal model for studies on rejuvenation. They can be easily isolated and cultured from their native niche in vivo. Furthermore, NSC deterioration with time might underlie some of the age-related cognitive decline. How can we convert ‘old’ NSCs into ‘young’ ones? To identify candidates enriched in the young state, I will compare young and old cells from the neural lineage, by focusing on microRNAs and transcription factors. Next, I will perform a detailed functional characterization, by conducting gain-of-function screens in NSCs, combined with novel readouts of youthfulness (e.g. fluorescent reporters) to understand how the identified factors exert their functions. Finally, to address the physiological relevance of my findings, I will evaluate the in vivo rejuvenating potential in mice.

Identifying the circuitry that determines the biological age of a cell will unravel a fundamental mystery in biology - why do cells age? This will have a major impact for advancing basic research in stem cell biology, regeneration, and aging.

Persistent structural and functional modifications of excitatory synapses are suggested to represent the cellular substrate of learning and memory. Dendritic spine morphology, like synaptic function, is dynamically regulated by neuronal activity. Changes in both spine morphology and synaptic efficacy are primarily influenced by actin remodeling. However, how dynamic actin filaments are anchored within dendritic spines and control their morphology and synaptic function remains unknown.
Our working hypothesis is that anchoring of actin filaments in dendritic spines represents a critical determinant of their dynamic and plastic behavior. Anchoring to the plasma membrane (‘peripheral anchor’) likely contributes to shape spine head and hinder the local diffusion of transmembrane proteins whereas anchoring at the base of the spine head (‘central anchor’) is required to generate enlargement forces upon actin polymerization. Elucidating the role of actin anchoring in dendritic spine structure, function and learning-related plasticity therefore represents the scientific aim of this proposal. To this end, we will develop and implement a highly multi-disciplinary approach based on the complementary expertise of the participants and a combination of i) advanced in vitro and in vivo electrophysiology, ii) cutting-edge imaging techniques, molecular tracking and super-resolution microscopy, iii) innovative photo-chemical tools for protein tagging, acute photoinactivation and crosslinking and iv) analysis of network activities and specific cognitive performances in behaving animals.
We will establish the role of peripheral and central anchors of F-actin in dendritic spines. We will combine single cell electrophysiology and molecular imaging techniques to explore the functional consequences of suppressing these anchors either genetically or acutely using protein photo-inactivation (CALI) techniques. Next, we will directly visualize the 3D network of spine actin, its modulation upon long term plasticity induction as well as its alterations upon selectively suppressing peripheral or central anchoring. We will also adapt molecular tagging to reveal the molecular organization of F-actin and its anchors within dendritic spines. We will then further identify the molecular components of peripheral and central anchors of F-actin in spine using new photo-crosslinking strategies to identify the molecular partners of peripheral and central actin anchors. Finally, we will combine our efforts to explore the importance of actin anchoring regulation in learning and memory processes by combining in vivo electrophysiology, photoinactivation and Ca imaging while monitoring cognitive performances measured in behavioral assays.

Age-associated cognition decline poses increasing social problems to the aging population highlighting the importance of a better understanding of age-dependent learning and memory impairment. Epigenetic modifications in the brain play a major role in the consolidation and long-term storage of memory but the underlying mechanisms, however, are poorly understood.
I propose to develop and apply novel epigenome perturbation technologies to study the role of neuronal circuit-specific DNA methylation changes in learning and memory, with the ultimate objective to identify genome-wide DNA methylation changes contributing to age-associated cognition decline. To accomplish the challenging but transformative goal I plan to develop and deliver novel light-inducible transcriptional effectors (LITEs) into the mouse brain to selectively turning on or off enzymes involved in DNA methylation. I further plan to develop and apply designer epigenetic modification enzymes (epiTALEs) to precisely manipulate specific DNA methylation targets. I will integrate these innovative technologies with state-of-the-art circuit and epigenetic analysis methods, mouse behavior and optogenetics. By using these tools I will be able to systematically probe different brain regions in a highly temporal and spatial resolution to identify both the DNA methylation targets and the brain circuits involved in normal learning and age-dependent memory impairment. This research plan will help to identify the epigenetic mechanisms that are causally involved in learning and memory and age-associated cognitive decline. It will further provide new therapeutic targets for cognitive and memory-related neurological disorders.

The ubiquitous small signaling molecule cyclic di-guanosinemonophosphate (c-di-GMP) is a key cellular regulator of biofilm formation and globally controls the motile-sessile switch of pathogenic and non-pathogenic bacteria. Despite of the broad importance of c-di-GMP for bacterial behavior and virulence, the underlying molecular and cellular processes remain poorly understood. C-di-GMP is a highly versatile signaling molecule regulating cellular processes at the transcriptional, translational and post-translational level. I propose to use the simple model system Caulobacter crescentus to study the effect of c-di-GMP on transcriptional regulation and on the timing of gene expression during the cell cycle. I will focus on three members of the Ros/MucR family of transcription repressors, candidates for c-di-GMP effectors and known regulators of exopolysaccharide biogenesis and motility in Sinorhizobium meliloti and of virulence determinants in Agrobacterium tumefaciens. I will elucidate the exact role and molecular mechanisms of the coupling of the MucR-c-di-GMP transcriptional regulation. Therefore, I will utilize a broad spectrum of techniques including RNASeq and ChipSeq to define the c-di-GMP-dependent MucR gene regulation network. Then, I will study the c-di-GMP-MucR- and MucR-DNA-binding kinetics in vitro, which forms the basis for the structural analysis of c-di-GMP-mediated DNA binding using crystallography. Finally, I will dissect the spatio-temporal timing of MucR transcriptional regulatory activities in single cells using live cell microscopy to integrate c-di-GMP-mediated differential gene expression into the asymmetric cell development program of C. crescentus.

Calcium is an extremely versatile second messenger, which controls almost all kind of cellular biological events.
As a single atom, calcium regulates biological function by changing its concentration, which is driven by the ~20,000 fold concentration difference between the extracellular environment and the cytoplasm. To avoid catastrophic cytoplasmic calcium induction, cells strictly limit calcium influxes. Activated channels are rapidly shut down and intruding cytoplasmic calcium is swiftly removed to the extracellular space or transferred into inner cellular membrane organelles. Accordingly, the combination of acute ion influx, point source ionic diffusion, and its immediate removal creates an ideal environment for calcium signal oscillations. Here, cardiomyocytes serve as a prime example where a wide range of cellular function is controlled by calcium signaling. Cardiomyocytes develop unique membrane micro domains termed “couplons” which structurally control calcium diffusion. These couplons work to not only couple membrane excitation to cell contractions, but also function as an electric synapse, through which calcium reciprocally controls membrane potentials. Nonetheless, our current understanding of cardiac couplon architecture and its dynamics is significantly lacking. Thus, by using cardiomyocytes as a model system, the goal of this project is to clarify how eukaryotic cells assemble junctional micro membrane domains that are effectively used to generate oscillating calcium signals, and define how these structures spatiotemporally control the information carried by this signal. This goal will be achieved by integrating the diverse expertise of our international team members. We will use 3-dimensional electron microscopy to determine the complete structure of couplons and their clusters, and paint the geometric models with distributions of nodal couplon molecules, determined both by diffraction limited and super-resolution light microscopy. Minimum molecular requirements to synthesize membrane junctions will also be determined and local membrane dynamics will be monitored by the use of newly designed fluorescent bio-reporters. In summary, successful completion of the current project is expected to provide fundamental knowledge of how micro-domain structures and their dynamics control the oscillatory behavior of membrane signaling.

In higher eukaryotes, the centrosome consists of a pair of centrioles and plays two distinct roles during cellular development. In cycling cells, centrosomes organize the interphase microtubule network and the mitotic spindle. In quiescent cells, one centriole forms the basal body and the primary cilium, which acts as an important platform for growth factor signaling. Important, unresolved questions are how the centriole switches between these distinct functions, and the role of growth factor signaling in this decision. Interestingly, many centriolar proteins are agonists (ß-catenin) and antagonists (Chibby, ß-catenin destruction complex) of canonical Wnt signaling, and they may function both as upstream regulators of ciliogenesis as well as downstream regulators of Wnt signaling. Furthermore, the kinase Nek2 targets ß-catenin and thereby promotes cell division. These observations suggest a role for Wnt in controlling the transition from a cycling centrosome to a basal body. In this project, I will use cell-based assays to test whether canonical Wnt signaling regulates centriole functions and antagonizes the centriole-basal body switch. I will investigate the behavior of centriolar Wnt-related factors during the centriole-basal body switch and the importance of Wnt-mediated transcription in ciliogenesis. Finally, I will address how centriolar ß-catenin is regulated by GSK3ß and Nek2, and how this relates to ciliogenesis. Together, these studies have great potential to provide us with insights on how the primary cilium is regulated, novel roles of centriolar factors in ciliogenesis and a better understanding of the Wnt pathway in the context of development and disease.

Identifying genetic risk variants for human diseases using genome-wide association studies is the essential first step towards establishing personalized genetic profiles. However, building predictive models of complex phenotypes that are useful in a medical setting has proved extremely challenging. Although many statistical methods have been developed in recent years, we know little about how the risk loci combine to determine the total genetic risk for an individual because of our limited understanding of the genetic architecture of human diseases. Yet, the predicted risk scores can be useful to identify individuals at high genetic risk of disease. In this project, we propose to use genome-wide prediction methods for a large number of cases from over a dozen of common disorders to explore the covariation of individual genetic risks among these conditions. We hypothesize that individuals at high risk for multiple disorders are likely to carry risk loci involved in gene-gene interactions resulting in covariation among phenotypes. Based on their predicted genetic risk scores, we will select subjects at high-risk for multiple diseases and examine the risk alleles they carry. Using integration methods that use prior biological knowledge, we expect to identify candidates loci for biologically relevant gene-gene interactions. These potential interactions will be further tested in cohorts of cases for specific diseases. Finally, we intend to incorporate information about biological interactions in prediction models to improve individual genetic profiling. The goal is to provide a better understanding of molecular disease phenotypes to perform reliable personalized medicine.

The centrosome is the major microtubule organizing center in animals and fungi, being implicated in several human diseases. The control of centrosome number, structure and localization is poorly understood. I will take advantage of comparative genomic and synthetic biology approaches to study how those structures are assembled. Recent studies suggest that the common ancestor of animals and fungi had, similarly to extant animals, a centrosome composed of two centrioles. Fission yeast lost the centriole and the genes needed to assemble it, having a centrosome equivalent, the spindle pole body (SPB). Despite their difference in structure, animal and yeast centrosomes share components, and both assemble only once per cell cycle and close to an already existing centrosome. This suggests a conserved ancestral program regulates centrosome assembly. I will use the fission yeast system as a “test tube” to study centrosome assembly, by expressing and studying the behavior of Drosophila centriole proteins in fission yeast. I will subsequently validate my findings in Drosophila. Preliminary experiments performed by the host laboratory show that Drosophila centriole proteins interact with the SPB machinery and with each other, validating the premises of this project. This project combines my expertise on the fission yeast cell cycle with the host laboratory expertise on centrosomes and cytoskeleton. This approach will identify the minimum conditions to regulate and assemble the unique structure of centrosomes.

Gene expression is a stochastic process controlled at multiple levels ranging from DNA promoter states through transcription and degradation rates to translation rates. The low numbers of molecules involved in many of the biochemical processes in the cell invariably lead to stochastic fluctuations in the amount of proteins expressed, but cells seem to have developed regulatory mechanisms to either reduce or amplify these fluctuations. Several studies characterized the extent and roles of stochastic gene expression in single cell organisms ranging from bacteria trough yeast to mammalian cells as well as in the development of multi-cellular organisms. However the extent and roles of noise and single-cell variability in cells operating within an intact adult mammalian tissue have not been studied. In this proposed interdisciplinary project we aim to use novel single molecule imaging methods to characterize multiples facets of gene expression in single cells in the intact mouse intestine. Specifically we aim to: 1) Develop a single molecule imaging technique to quantify transcriptional bursts and RNA degradation in intact mammalian tissues. 2) Study the roles of stochastic gene expression in modulating differentiation decisions of intestinal stem cells. 3) Study the roles of RNA degradation in rapidly switching gene expression programs in the mouse intestine. The HFSP fellowship was essential for the emergence of my current research project, and the CDA will provide the financial support and scientific independence to develop it.

A central goal of modern neurobiology is to understand the neural mechanisms that convert sensory inputs from the outside world into behavioral outputs that generate specific actions. While a great deal is known about the general organization of the circuits underlying olfaction -- the main sensory modality used by most animals to interact with their environment -- the functional architecture of the wiring that transforms olfactory inputs into behavioral outputs has not been described. In addition, no mechanism has been described to explain why certain odors, such as those from food, predators and mates, evoke profound and innate behavioral changes, while most odors lack behavioral meaning without prior learning.
Here we propose experiments testing the hypothesis that innate behavioral responses to odors are generated by the interplay between the amygdala, a part of the brain involved in emotional processing, and the ventral striatum, which is critical for linking sensory inputs to motor outputs. This hypothesis has, to date, been untestable because of limitations imposed by the deep location of the ventral striatum. By taking advantage of a newly-developed surgical preparation that exposes the olfactory tubercle, a subregion of the ventral striatum, in living animals we will directly address this hypothesis. We will use a combination of in vivo whole-cell recordings, functional calcium imaging, optogenetic manipulations and behavioral analysis to reveal how olfactory circuits transform signals about the environment to lead to appropriate actions.

miRNAs are genome-encoded small RNAs that canonically repress translation of target mRNAs, which they recognize by base-pairing. In contrast, the non-canonical function of miRNAs in translational activation in G0-phase cells has been reported. Our knowledge of miRNA-mediated translational activation is still limited; in particular, it is unclear whether miRNA-mediated translational activation affects endogenous mRNAs significantly. The main aim of my research will be the genome-wide evaluation of miRNA-mediated translational activation in endogenous mRNAs. As quiescent and post-mitotic cells are pervasive in living organisms, our results will reveal important aspects of miRNA biology that have been overlooked in standard culture systems.
I will address endogenous activation targets using ribosome profiling. Ribosome profiling is a method based on deep sequencing of RNA fragments protected by ribosomes that measures the translation of each mRNA quantitatively. I will introduce miRNAs into G0-phase HeLa cells, synchronized by serum-starvation, and analyze how miRNA-mediated translational activation impacts endogenous mRNAs, how miRNAs activate translation, and how differently miRNAs recognize the target mRNAs.
One of my previous reports has suggested that the poly(A) tail of target mRNAs might be a key factor for miRNA-mediated translational activation. I will address the impact of polyadenylation by RNA-Seq analysis of poly(A)+ and poly(A)- fractions of rRNA-depleted RNA and high resolution poly(A) tail assay (Hire-PAT). This result will provide insights for the function of poly(A) tail in miRNA-mediated translational activation.

Meiotic recombination has two key roles, it creates genetic diversity and promotes accurate segregation of chromosomes during meiotic cell division. Despite a plethora of knowledge about the genetic control of this process in lower eukaryotes, revealed primarily through forward genetic screens, our understanding of it in higher eukaryotes is lacking. This is due to the rapid divergence of meiotic proteins through evolution, which has limited the standard reverse genetic approaches. I will exploit our current knowledge of meiotic recombination in higher organisms and the recent advances in genomics, to conduct an ENU mutagenesis genome wide screen in mice for players of meiotic recombination and chromosome structure. As a readout for my screen, I will use behaviour of thoroughly described and robust indicators of double strand break repair and chromosome structure, namely phosphorylated histone H2AX called gamma-H2AX and synaptonemal complex protein SYCP3. This will not only allow me to identify proteins directly involved in the formation and repair of double strand breaks, but will also uncover components of the meiotic protein scaffold and those involved in sex chromosome inactivation. Subsequent characterisation of the candidates identified from my screen will allow me to bridge the gap and enhance our understanding of several aspects of the mammalian system, from DNA repair, to meiotic chromatin organisation, to conservation of the underlying strategies of meiosis.

This project aims to decipher how circadian gene expression is regulated on the translational level. Circadian clocks coordinate the daily timing of most physiological processes. During the last decade numerous molecular studies have used genome-wide transcriptome analyses to define rhythmic gene expression. However, proteomic approaches have shown a surprisingly high discrepancy between the circadian transcriptome and proteome, pointing to additional levels of circadian regulation. Circadian translational control is an attractive hypothesis for how rhythmic protein accumulation might be achieved from non-circadian transcripts. However, such translational mechanisms are still poorly investigated in the circadian field.
We will implement a recently developed technique termed “ribosome-profiling” to determine circadian translation rates in mouse liver in a genome-wide and quantitative fashion. In particular, we aim to discover proteins that are rhythmically translated from stable transcripts throughout the day. Based on the sequence information of these transcripts we will make predictions about molecular mechanisms and interaction partners that are involved in circadian translation. Hypotheses generated by these approaches will be assessed using in vitro and in vivo systems. Finally, loss-of-function analyses in different mouse models will give information about the relevance of the uncovered mechanisms for liver physiology.

Recently, our laboratory has shown that cancer cells need both genetic mutations and epigenetic alterations for their continuous growth. This was revealed through a focused RNAi screen where all epigenetic regulators were systematically evaluated for their role in proliferation of acute myeloid leukemia (AML). I performed a new RNAi screen in acute lymphoblastic leukemia (ALL). Remarkably, this screen identified that TRIM33 (Tripartite motif-containing 33) is required for the growth of ALL but not for 10 other forms of cancer tested. TRIM33 harbors a PHD and a bromodomain which recognizes methylated and acetylated histones, respectively. While TRIM33 is uniquely required for growth of ALL cells, I found surprisingly that TRIM33 is expressed ubiquitously in many cell types. Therefore, TRIM33 promotes growth of ALL in a highly context-specific manner, which might be related to the underlying genetic/epigenetic cellular state. To understand the mechanism underlying this intriguing phenotype, I will establish a tractable mouse-model system in which we can manipulate cellular genetic/epigenetic contextual features to evaluate the key determinants of TRIM33-addiction. This powerful system will enable us a comprehensive evaluation of TRIM33 function in ALL, which will include: 1) identifying the target genes of TRIM33 2) revealing genome-wide distribution of TRIM33 3) purifyingTRIM33-containing complexes in multiple cell types, and 4) reconstituting TRIM33 functions in vitro. The central goal of this project will be to define the context-specific mechanism that accounts for the addiction of ALL cells to TRIM33, a novel therapeutic target in this untreatable disease.

The vulva of the Caenorhabditis elegans (C. elegans) is the egg-laying and copulatory organ of the hermaphrodite (or female) and connects the uterus to the outside of the nematode. Due to its simple cellular organization and accessibility in-vivo, the developing vulva has become a paradigm for organogenesis and the two main molecular pathways underlying vulval patterning are mapped out in great detail. However, a quantitative understanding of the interplay between environmental factors and these molecular pathways is still lacking. Therefore, our first aim is to identify specific environmental cues that induce classifiable and numerically significant phenotypic effects on vulval development for wild-type C. elegans strains. From prior work on Drosophila and male nematodes, for instance, we expect that heat shocks during early developmental stages exert a strong influence on vulva phenotypes. Next, we will apply the identified experimental protocols to the classical pathway mutant strains. We expect that the same types of environmental perturbation will have a different effect in these mutants. These data will now be fit to a very recently introduced quantitative model, which to establishes the genotype to phenotype map via only a few aggregate variables. These fits will yield a quantitative correspondence between signaling pathways and environmental perturbations and enable us to dissect effective interactions between mutant genes and environmental stresses. They will furthermore allow us to infer specific perturbations that should be applied to one mutant strain in order to induce phenotypes of another. This model prediction will finally be experimentally tested.

Meiosis, the key to sexual reproduction, is a special cell division process that mediates the production of haploid gametes from diploid parental cells. To this end, meiosis critically depends on the accurate segregation of homologous chromosomes. Errors in this process are a major cause of infertility, and can also result in developmental disorders such as Down syndrome. However, the mechanisms regulating homologous pairing and its stabilization by the formation of the synaptonemal complex and recombination still remain unclear. In the proposed project I will investigate the role of cytoskeletal forces in meiotic chromosome pairing and synapsis. I will take advantage of the wealth of tools available to study meiotic chromosomes in the nematode Caenorhabditis elegans. By generating transgenic nematodes expressing novel fluorescent reporters, I will directly visualize the forces acting on meiotic chromosomes through in vivo imaging and image analysis. Using these tools, I will investigate the roles of specific molecular components, including the microtubule motor dynein, and HORMA-domain proteins, a family of conserved proteins of the meiotic chromosome axis. These experiments will test the hypothesis that forces generated by motors acting on the microtubule cytoskeleton create tension between homologous chromosomes to ensure accurate pairing. I will also explore how physical forces are transduced through the intact nuclear envelope, and along the length of the chromosomes. My analysis will advance our understanding of the regulatory mechanisms that ensure faithful chromosome segregation and genome stability.

T-cell acute lymphoblastic leukemia (T-ALL) is an aggressive hematologic neoplasm resulting from the malignant transformation of T-cell progenitor cells. Despite the improved cure rate for childhood T-ALL, up to 25% of patients will fail frontline therapy and their prognosis is dismal. This is mainly because most efforts in understanding T-ALL biology have focused on the protein-coding genome, which represents less than 2% of our genetic material. Consequently, the molecular mechanisms underlying the disease are poorly understood. Non-coding RNAs (ncRNAs) have been shown to regulate important biological processes that support normal cellular functions. Here, I propose to investigate the implication of long ncRNAs (lncRNAs) in the pathogenesis of leukemia. I will perform whole transcriptome sequencing studies in primary and relapsed patient samples to identify and comprehensively annotate T-ALL-specific lncRNAs. I will functionally characterize the identified lncRNAs by loss and gain of function approaches to assess their contribution in induction and maintenance of T-ALL in vitro and in mouse xenograft models. Furthermore, I will test the lncRNAs expression in response to T-ALL targeted drug treatments, which will identify lncRNAs modulated by specific oncogenes. The proposed study will uncover a novel resource of important prognostic markers and will contribute to the complete understanding of mechanisms driving pathogenesis in T-ALL.

Neuronal circuits in the brain are constantly modified by external sensory experience. Synapses, the smallest unit of information processing in the brain, are highly dynamic in function and structure. It is still unclear how sensory experience is coded by synaptic function and structure. New imaging techniques have enabled high resolution exploration of dendritic spines, specialized post synaptic sites, in the living brain. These studies have focused on long term spine structural dynamics at time scales ranging from hours to days and months. However, it is not known how ongoing sensory experience may be rapidly transformed to synaptic structural and functional dynamics in the brain. Therefore, our main research aim is to address how a specific sensory input might change the structure and function of single spines. We propose to examine this question by combining in-vivo 2 photon imaging along with FLIM measurements of protein dynamics in single spines during the presentation of specific sensory input. By use of an optical cranial window and viral expression of tagged molecular sensors, this experimental setup could be utilized to examine how specific sensory experience is transformed into rapid structural and functional plasticity of synapses deep in the brain. Furthermore, we propose to examine how rapid spine dynamics corresponds to long term alterations in spine structures, which is associated with learning and memory. This project may help to better understand how sensory experience and learning is represented in rapid synaptic dynamics, and how these early events can lead to long term synaptic plasticity, enabling the brain to create novel memories while stably maintaining them over time.

Many microorganisms produce antibiotic compounds that target essential components of prokaryotic and eukaryotic cells. Xenobiotic production provides a means to disable competing microbes or host defenses to infection. Animals encounter these toxins in their environment, and posses a range of mechanisms mitigate their effects. These detoxification responses are tightly regulated, but how this regulation is achieved is poorly understood. In C. elegans, disruption of core cellular processes by RNAi activates the same detoxification responses that occur upon exposure to xenobiotics. This indicates that surveillance of core cellular processes, rather than detection of xenobiotics themselves, serves to trigger detoxification. I aim to understand the mechanism of surveillance of core cellular processes, and how information from this surveillance is relayed to regulate detoxification responses. I will use large-scale mutagenesis screens to identify factors that regulate detoxification responses, and transcriptome sequencing to gain a genome-wide view of their regulatory outputs. Some xenobiotic detoxification responses are regulated by endocrine signals. To distinguish factors that act in surveillance and responding tissues, I will establish a system for tissue-specific induction of xenobiotic stress. This work will constitute the first systematic genetic and genomic analysis of detoxification regulation in any animal. Conserved factors identified in C. elegans promise new insights into human disease and drug responses mechanisms.