Phospholipase D (PLD) is an enzyme implicated in the regulation of both exocytic and endocytic vesicle trafficking as well as many other processes. Consistent with this, the small GTPase Arf6 and regulated changes in inositol phospholipids levels are two factors that regulate both PLD and vesicle trafficking. Here we describe three methodologies through which the activation of PLD by Arf6 and inositol phospholipids may be investigated. The first method described is an in vitro protocol that allows the analysis of purified proteins or cell lysates. Furthermore, this protocol can be used to analyze the effects of different inositol phospholipids by changing the composition of the substrate vesicle. The major advantage of this protocol lies in the ability to analyze the effects of direct interactions on PLD activation by using pure proteins and lipids. The other two methods are in vivo protocols for the analysis of PLD activation in response to extracellular stimuli. Modification of cellular composition using overexpression/deletion or knockout of specific genes can be utilized with these protocols to characterize PLD activation pathways. The first of these methods uses the detection of radiolabeled PLD products and can be used for most cell types whereas the second of these two protocols is used to measure PLD products when radiolabeling of cells is not possible, such as freshly isolated cells that will not survive long enough to attain radiochemical equilibrium.

The cis-acting regulatory sequences of imprinted genes are subject to germline-specific epigenetic modifications, the imprints, so that this class of genes is exclusively expressed from either the paternal or maternal allele in offspring. How genes are differentially marked in the germlines remains largely to be elucidated. Although the exact nature of the mark is not fully known, DNA methylation [at differentially methylated regions (DMRs)] appears to be a major, functional component. Recent data in mice indicate that Dnmt3a, an enzyme with de novo DNA methyltransferase activity, and the related protein Dnmt3L are required for methylation of imprinted loci in germ cells. Maternal methylation imprints, in particular, are strictly dependent on the presence of Dnmt3L. Here, we show that, unexpectedly, methylation imprints can be present in some progeny of Dnmt3L(-/-) females. This incomplete penetrance of the effect of Dnmt3L deficiency in oocytes is neither embryo nor locus specific, but stochastic. We establish that, when it occurs, methylation is present in both embryo and extra-embryonic tissues and results in a functional imprint. This suggests that this maternal methylation is inherited, directly or indirectly, from the gamete. Our results indicate that in the absence of Dnmt3L, factors such as Dnmt3a and possibly others can act alone to mark individual DMRs. However, establishment of appropriate maternal imprints at all loci does require a combination of all factors. This observation can provide a basis to understand mechanisms involved in some sporadic cases of imprinting-related diseases and polymorphic imprinting in human.

Wallerian degeneration of injured neuronal axons and synapses is blocked in Wld(S) mutant mice by expression of an nicotinamide mononucleotide adenylyl transferase 1 (Nmnat-1)/truncated-Ube4b chimeric gene. The protein product of the Wld(S) gene localizes to neuronal nuclei. Here we show that Wld(S) protein expression selectively alters mRNA levels of other genes in Wld(S) mouse cerebellum in vivo and following transfection of human embryonic kidney (HEK293) cells in vitro. The largest changes, identified by microarray analysis and quantitative real-time polymerase chain reaction of cerebellar mRNA, were an approximate 10-fold down-regulation of pituitary tumour-transforming gene-1 (pttg1) and an approximate 5-fold up-regulation of a structural homologue of erythroid differentiation regulator-1 (edr1l-EST). Transfection of HEK293 cells with a Wld(S)-eGFP construct produced similar changes in mRNA levels for these and seven other genes, suggesting that regulation of gene expression by Wld(S) is conserved across different species, including humans. Similar modifications in mRNA levels were mimicked for some of the genes (including pttg1) by 1 mm nicotinamide adenine dinucleotide (NAD). However, expression levels of most other genes (including edr1l-EST) were insensitive to NAD. Pttg1(-/-) mutant mice showed no neuroprotective phenotype. Transfection of HEK293 cells with constructs comprising either full-length Nmnat-1 or the truncated Ube4b fragment (N70-Ube4b) demonstrated selective effects of Nmnat-1 (down-regulated pttg1) and N70-Ube4b (up-regulated edr1l-EST) on mRNA levels. Similar changes in pttg1 and edr1l-EST were observed in the mouse NSC34 motor neuron-like cell line following stable transfection with Wld(S). Together, the data suggest that the Wld(S) protein co-regulates expression of a consistent subset of genes in both mouse neurons and human cells. Targeting Wld(S)-induced gene expression may lead to novel therapies for neurodegeneration induced by trauma or by disease in humans.

BioModels Database (http://www.ebi.ac.uk/biomodels/), part of the international initiative BioModels.net, provides access to published, peer-reviewed, quantitative models of biochemical and cellular systems. Each model is carefully curated to verify that it corresponds to the reference publication and gives the proper numerical results. Curators also annotate the components of the models with terms from controlled vocabularies and links to other relevant data resources. This allows the users to search accurately for the models they need. The models can currently be retrieved in the SBML format, and import/export facilities are being developed to extend the spectrum of formats supported by the resource.

Ligand-gated ion channels form transmembrane ionic pores controlled by the binding of chemicals. The LGICdb aims to be a non-redundant, manually curated resource offering access to the large number of subunits composing extracellularly activated ligand-gated ion channels, such as nicotinic, ATP, GABA and glutamate ionotropic receptors. Composed of more than 500 human curated entries, the XML native database has been relocated in 2004 to the EBI. Its facilities have been enhanced with a new search system, customized multiple sequence alignments and manipulation of protein structures (http://www.ebi.ac.uk/compneur-srv/LGICdb/). Despite the vast improvement of general sequence resources, the LGICdb still provide sequences unavailable elsewhere.

Antigens coated with complement fragments coligate the B cell receptor (BCR) with the CD21/CD19 complex which results in synergistic activation of B cells. Previous studies identified PI3K, Vav proteins and PLCgamma as important components of this synergy. We now show that protein kinase D (also known as PKCmu) is also a point of convergence of these signalling pathways. We found that PKD activation upon BCR engagement or coligation of the BCR with CD19 is entirely dependent on PI3K and PLCgamma but differ in the requirement for Vav proteins. Whereas PKD activation is Vav1 and Vav2 dependent in response to BCR cross-linking, PKD activation is sensitive to the lack of Vav1 under synergistic stimulation of BCR and CD19. These findings show that Vav proteins and PI3K regulation of PLCgamma contributes to the activation of PKD in response to BCR and or CD19 cross-linking.

Recent analyses have shown that the activity of the yeast nuclear exosome is stimulated by the Trf4p-Air1/2p-Mtr4p polyadenylation (TRAMP) complex. Here, we report that strains lacking the Rrp6p component of the nuclear exosome accumulate polyadenylated forms of many different ribosomal RNA precursors (pre-rRNAs). This polyadenylation is reduced in strains lacking either the poly(A) polymerase Trf4p or its close homologue Trf5p. In contrast, polyadenylation is enhanced by overexpression of Trf5p. Polyadenylation is also markedly increased in strains lacking the RNA helicase Mtr4p, indicating that it is required to couple poly(A) polymerase activity to degradation. Tandem affinity purification-tagged purified Trf5p showed polyadenylation activity in vitro, which was abolished by a double point mutation in the predicted catalytic site. Trf5p co-purified with Mtr4p and Air1p, indicating that it forms a complex, designated TRAMP5, that has functions that partially overlap with the TRAMP complex.

Slow Wallerian degeneration (Wld(S)) mutant mice express a chimeric nuclear protein that protects sick or injured axons from degeneration. The C-terminal region, derived from NAD(+) synthesizing enzyme Nmnat1, is reported to confer neuroprotection in vitro. However, an additional role for the N-terminal 70 amino acids (N70), derived from multiubiquitination factor Ube4b, has not been excluded. In wild-type Ube4b, N70 is part of a sequence essential for ubiquitination activity but its role is not understood. We report direct binding of N70 to valosin-containing protein (VCP; p97/Cdc48), a protein with diverse cellular roles including a pivotal role in the ubiquitin proteasome system. Interaction with Wld(S) targets VCP to discrete intranuclear foci where ubiquitin epitopes can also accumulate. Wld(S) lacking its N-terminal 16 amino acids (N16) neither binds nor redistributes VCP, but continues to accumulate in intranuclear foci, targeting its intrinsic NAD(+) synthesis activity to these same foci. Wild-type Ube4b also requires N16 to bind VCP, despite a more C-terminal binding site in invertebrate orthologues. We conclude that N-terminal sequences of Wld(S) protein influence the intranuclear location of both ubiquitin proteasome and NAD(+) synthesis machinery and that an evolutionary recent sequence mediates binding of mammalian Ube4b to VCP.

The mammalian fetus is unique in its dependence during gestation on the supply of maternal nutrients through the placenta. Maternal supply and fetal demand for nutrients need to be fine tuned for healthy growth and development of the fetus along its genetic trajectory. An altered balance between supply and demand can lead to deviations from this trajectory with long-term consequences for health. We have previously shown that in a knockout lacking the imprinted placental-specific Igf2 transcript (P0), growth of the placenta is compromised from early gestation but fetal growth is normal until late gestation, suggesting functional adaptation of the placenta to meet the fetal demands. Here, we show that placental transport of glucose and amino acids are increased in the Igf2 P0(+/-) null and that this up-regulation of transport occurs, at least in part, through increased expression of the transporter genes Slc2a3 and Slc38a4, the imprinted member of the System A amino acid transporter gene family. Decreasing fetal demand genetically by removal of fetal Igf2 abolished up-regulation of both transport systems and reduced placental System A amino acid transport activity and expression of Slc38a2 in late gestation. Our results provide direct evidence that the placenta can respond to fetal demand signals through regulation of expression of specific placental transport systems. Thus, crosstalk between an imprinted growth demand gene (Igf2) and placental supply transporter genes (Slc38a4, Slc38a2, and Slc2a3) may be a component of the genetic control of nutrient supply and demand during mammalian development.

Matrix-assisted laser desorption/ionization (MALDI)-time-of-flight (TOF)-mass spectrometry (MS) is now routinely used in many laboratories for the rapid and sensitive identification of proteins by peptide mass fingerprinting (PMF). We describe a simple protocol that can be performed in a standard biochemistry laboratory, whereby proteins separated by one- or two-dimensional gel electrophoresis can be identified at femtomole levels. The procedure involves excision of the spot or band from the gel, washing and de-staining, reduction and alkylation, in-gel trypsin digestion, MALDI-TOF MS of the tryptic peptides, and database searching of the PMF data. Up to 96 protein samples can easily be manually processed at one time by this method.

Most of the published quantitative models in biology are lost for the community because they are either not made available or they are insufficiently characterized to allow them to be reused. The lack of a standard description format, lack of stringent reviewing and authors' carelessness are the main causes for incomplete model descriptions. With today's increased interest in detailed biochemical models, it is necessary to define a minimum quality standard for the encoding of those models. We propose a set of rules for curating quantitative models of biological systems. These rules define procedures for encoding and annotating models represented in machine-readable form. We believe their application will enable users to (i) have confidence that curated models are an accurate reflection of their associated reference descriptions, (ii) search collections of curated models with precision, (iii) quickly identify the biological phenomena that a given curated model or model constituent represents and (iv) facilitate model reuse and composition into large subcellular models.

The pre-B-cell receptor (pre-BCR), composed of Ig heavy and surrogate light chain (SLC), signals pre-BII-cell proliferative expansion. We have investigated whether the pre-BCR also signals downregulation of the SLC genes (VpreB and lambda5), thereby limiting this expansion. We demonstrate that, as BM cells progress from the pre-BI to large pre-BII-cell stage, there is a shift from bi- to mono-allelic lambda5 transcription, while the second allele is silenced in small pre-BII cells. A VpreB1-promoter-driven transgene shows the same pattern, therefore suggesting that VpreB1 is similarly regulated and thereby defines the promoter as a target for transcriptional silencing. Analyses of pre-BCR-deficient mice show a temporal delay in lambda5 downregulation, thereby demonstrating that the pre-BCR is essential for monoallelic silencing at the large pre-BII-cell stage. Our data also suggest that SLP-65 is one of the signaling components important for this process. Furthermore, the VpreB1/lambda5 alleles undergo dynamic changes with respect to nuclear positioning and heterochromatin association, thereby providing a possible mechanism for their transcriptional silencing.

Different causes, such as maternal diabetes, cloning by nuclear transfer, interspecific hybridization, and deletion of some genes such as Esx1, Ipl, or Cdkn1c, may underlie placental overgrowth. In a previous study, we carried out comparative gene expression analysis in three models of placental hyperplasias, cloning, interspecies hybridization (IHPD), and Esx1 deletion. This study identified a large number of genes that exhibited differential expression between normal and enlarged placentas; however, it remained unclear how altered expression of any specific gene was related to any specific placental phenotype. In the present study, we focused on two genes, Car2 and Ncam1, which both exhibited increased expression in interspecies and cloned hyperplastic placentas. Apart from a detailed expression analysis of both genes during normal murine placentation, we also assessed morphology of placentas that were null for Car2 or Ncam1. Finally, we attempted to rescue placental hyperplasia in a congenic model of IHPD by decreasing transcript levels of Car2 or Ncam1. In situ analysis showed that both genes are expressed mainly in the spongiotrophoblast, however, expression patterns exhibited significant variability during development. Contrary to expectations, homozygous deletion of either Car2 or Ncam1 did not result in placental phenotypes. However, expression analysis of Car3 and Ncam2, which can take over the function of Car2 and Ncam1, respectively, indicated a possible rescue mechanism, as Car3 and Ncam2 were expressed in spongiotrophoblast of Car2 and Ncam1 mutant placentas. On the other hand, downregulation of either Car2 or Ncam1 did not rescue any of the placental phenotypes of AT24 placentas, a congenic model for interspecies hybrid placentas. This strongly suggested that altered expression of Car2 and Ncam1 is a downstream event in placental hyperplasia.

Rac GTPases regulate cytoskeletal structure, gene expression, and reactive oxygen species (ROS) production. Rac2-deficient neutrophils cannot chemotax, produce ROS, or degranulate upon G protein-coupled receptor (GPCR) activation. Deficiency in PI3Kgamma, an upstream regulator of Rac, causes a similar phenotype. P-Rex1, a guanine-nucleotide exchange factor (GEF) for Rac, is believed to link GPCRs and PI3Kgamma to Rac-dependent neutrophil responses. We have investigated the functional importance of P-Rex1 by generating a P-Rex1(-/-) mouse. P-Rex1(-/-) mice are viable and healthy, with apparently normal leukocyte development, but with mild neutrophilia. In neutrophils from P-Rex1(-/-) mice, GPCR-dependent Rac2 activation is impaired, whereas Rac1 activation is less compromised. GPCR-dependent ROS formation is absent in lipopolysaccharide (LPS)-primed P-Rex1(-/-) neutrophils, but less affected in unprimed or TNFalpha-primed cells. Recruitment of P-Rex1(-/-) neutrophils to inflammatory sites is impaired. Surprisingly, chemotaxis of isolated neutrophils is only slightly reduced, with a mild defect in cell speed, but normal polarization and directionality. Secretion of azurophil granules is unaffected. In conclusion, P-Rex1 is an important regulator of neutrophil function by mediating a subset of Rac-dependent neutrophil responses. However, P-Rex1 is not an essential regulator of neutrophil chemotaxis and degranulation.

A wide range of insults can trigger axon degeneration, and axons respond with diverse morphology, topology and speed. However, recent genetic, immunochemical, morphological and pharmacological investigations point to convergent degeneration mechanisms. The principal convergence points - poor axonal transport, mitochondrial dysfunction and an increase in intra-axonal calcium - have been identified by rescuing axons with the slow Wallerian degeneration gene (Wld(S)) and studies with blockers of sodium or calcium influx. By understanding how the pathways fit together, we can combine our knowledge of mechanisms, and potentially also treatment strategies, from different axonal disorders.

Low back pain is one of the largest health problems in the Western world today, and intervertebral disc degeneration has been identified as a main cause. Currently, treatments are symptomatic, but cell-based tissue engineering methods are realistic alternatives for tissue regeneration. However, the major problem for these strategies is the generation of a suitable population of cells. Adult bone marrow-derived mesenchymal stem cells (MSCs) are undifferentiated, multipotent cells that have the ability to differentiate into a number of cell types, including the chondrocyte-like cells found within the nucleus pulposus (NP) of the intervertebral disc; however, no method exists to differentiate these cells in an accessible monolayer environment. We have conducted coculture experiments to determine whether cells from the human NP can initiate the differentiation of human MSCs with or without cell-cell contact. Fluorescent labeling of the stem cell population and high-speed cell sorting after coculture with cell-cell contact allowed examination of individual cell populations. Real-time quantitative polymerase chain reaction showed significant increases in NP marker genes in stem cells when cells were cocultured with contact for 7 days, and this change was regulated by cell ratio. No significant change in NP marker gene expression in either NP cells or stem cells was observed when cells were cultured without contact, regardless of cell ratio. Thus, we have shown that human NP and MSC coculture with contact is a viable method for generating a large population of differentiated cells that could be used in cell-based tissue engineering therapies for regeneration of the degenerate intervertebral disc.

Purified membrane vesicles isolated from sea urchin eggs form nuclear envelopes around sperm nuclei following GTP hydrolysis in the presence of cytosol. A low density subfraction of these vesicles (MV1), highly enriched in phosphatidylinositol (PtdIns), is required for nuclear envelope formation. Membrane fusion of MV1 with a second fraction that contributes most of the nuclear envelope can be initiated without GTP by an exogenous bacterial PtdIns-specific phospholipase C (PI-PLC) which hydrolyzes PtdIns to form diacylglycerides and inositol 1-phosphate. This PI-PLC hydrolyzes a subset of sea urchin membrane vesicle PtdIns into diglycerides enriched in long chain, polyunsaturated species as revealed by a novel liquid chromatography-mass spectrometry analysis. Large unilammelar vesicles (LUVs) enriched in PtdIns can substitute for MV1 in PI-PLC induced nuclear envelope formation. Moreover, MV1 prehydrolyzed with PI-PLC and washed to remove inositols leads to spontaneous nuclear envelope formation with MV2 without further PI-PLC treatment. LUVs enriched in diacylglycerol mimic prehydrolyzed MV1. These results indicate that production of membrane-destabilizing diglycerides in membranes enriched in PtdIns may facilitate membrane fusion in a natural membrane system and suggest that MV1, which binds only to two places on the sperm nucleus, may initiate fusion locally.

Insect octopamine receptors are G-protein coupled receptors. They can be coupled to second messenger pathways to mediate either increases or decreases in intracellular cyclic AMP levels or the generation of intracellular calcium signals. Insect octopamine receptors were originally classified on the basis of second messenger changes induced in a variety of intact tissue preparations. Such a classification system is problematic if more than one receptor subtype is present in the same tissue preparation. Recent progress on the cloning and characterization in heterologous cell systems of octopamine receptors from Drosophila and other insects is reviewed. A new classification system for insect octopamine receptors into "alpha-adrenergic-like octopamine receptors (OctalphaRs)", "beta-adrenergic-like octopamine receptors (OctbetaRs)" and "octopamine/tyramine (or tyraminergic) receptors" is proposed based on their similarities in structure and in signalling properties with vertebrate adrenergic receptors. In future studies on the molecular basis of octopamine signalling in individual tissues it will be essential to identify the relative expression levels of the different classes of octopamine receptor present. In addition, it will be essential to identify if co-expression of such receptors in the same cells results in the formation of oligomeric receptors with specific emergent pharmacological and signalling properties.

In order to exploit the exceptional potential of human embryonic stem cells (hESCs) in cell-replacement therapies, the genetic and epigenetic factors controlling early human development must be better defined. Limitations in human embryonic material restrict the scale of studies that can be performed, and therefore an in vitro model in which to study epigenetic regulation in human preimplantation cell types would be desirable. HESCs could provide such a model, but since they are derived from a stage in mammalian development when the genome is undergoing global epigenetic remodelling, it is unclear whether their epigenetic status would be stable or subject to variation. Herein, we discuss recent work that examines allele-specific imprinted gene expression and methylation patterns, thereby demonstrating that hESCs maintain a substantial degree of epigenetic stability during culture. Therefore, we suggest that hESCs could provide a model for studying epigenetic regulation during the early stages of human cellular pluripotency and differentiation. Furthermore, we propose specific experiments using such a model to address important questions pertaining to epigenetic mechanisms of certain human disorders.

Phospholipase C-gamma2 (PLC-gamma2) is a key component of signal transduction in leukocytes. In natural killer (NK) cells, PLC-gamma2 is pivotal for cellular cytotoxicity; however, it is not known which steps of the cytolytic machinery it regulates. We found that PLC-gamma2-deficient NK cells formed conjugates with target cells and polarized the microtubule-organizing center, but failed to secrete cytotoxic granules, due to defective calcium mobilization. Consequently, cytotoxicity was completely abrogated in PLC-gamma2-deficient cells, regardless of whether targets expressed NKG2D ligands, missed self major histocompatibility complex (MHC) class I, or whether NK cells were stimulated with IL-2 and antibodies specific for NKR-P1C, CD16, CD244, Ly49D, and Ly49H. Defective secretion was specific to cytotoxic granules because release of IFN-gamma on stimulation with IL-12 was normal. Plcg2-/- mice could not reject MHC class I-deficient lymphoma cells nor could they control CMV infection, but they effectively contained Listeria monocytogenes infection. Our results suggest that exocytosis of cytotoxic granules, but not cellular polarization toward targets, depends on intracellular calcium rise during NK cell cytotoxicity. In vivo, PLC-gamma2 regulates selective facets of innate immunity because it is essential for NK cell responses to malignant and virally infected cells but not to bacterial infections.

ART2 (RT6) belongs to the family of mono-ADP-ribosyltransferases (ARTs). ART2 is a T-cell differentiation marker expressed by the majority of mature peripheral T cells in the rat. The two known ART2 allotypes display approximately 95% amino acid identity. We sequenced the ART2 coding regions from 18 inbred rat strains and found two additional alleles, termed Art2 ( a2 ) and Art2 ( b2 ). Monoclonal antibody Gy12/61 specifically reacted with Art2 ( a2 ) but not Art2 ( a1 ) lymph node cells. Expression of ART2 allotypes in Jurkat cells confirmed this specificity. A polymerase chain reaction (PCR) assay using restriction fragment length polymorphisms is described, which allows the easy discrimination of Art2 alleles. All four laboratory rat alleles, as well as an additional sequence variant, were found amongst 18 wild rat DNA samples. PCR analysis confirmed the selective presence of a rodent identifier (ID) element in the Art2 ( a ) but not the Art2 ( b ) alleles in all rats studied. Analysis of Art2 ( a1 ) and Art2 ( b2 ) genes showed greater divergence in coding than in non-coding regions. Together with the finding of a high number of non-synonymous mutations leading mostly to non-conservative amino acid substitutions clustered on the side facing away from the cell surface, this suggests that the Art2 polymorphism has been subject to selection.

Mouse gene-targeting studies have documented a central role of the p110delta isoform of phosphoinositide 3-kinase (PI3K) in B-cell development and function. A defect in B-cell antigen receptor (BCR) signaling is key to this B-cell phenotype. Here we further characterize this signaling defect and report that a p110delta-selective small molecule inhibitor mirrors the effect of genetic inactivation of p110delta in BCR signaling. p110delta activity is indispensable for BCR-induced DNA synthesis and phosphorylation of Akt/protein kinase B (PKB), forkhead transcription factor/forkhead box O3a (FOXO3a), and p70 S6 kinase (p70 S6K), with modest effects on the phosphorylation of glycogen synthase kinase 3 alpha/beta (GSK3alpha/beta) and extracellular signal-regulated kinase (Erk). The PI3K-dependent component of intracellular calcium mobilization also completely relies on p110delta catalytic activity. Resting B cells with inactive p110delta fail to enter the cell cycle, correlating with an incapacity to up-regulate the expression of cyclins D2, A, and E, and to phosphorylate the retinoblastoma protein (Rb). p110delta is also critical for interleukin 4 (IL-4)-induced phosphorylation of Akt/PKB and FOXO3a, and protection from apoptosis. Taken together, these data show that defects observed in p110delta mutant mice are not merely a consequence of altered B-cell differentiation, and emphasize the potential utility of p110delta as a drug target in autoimmune diseases in which B cells play a crucial role.

Transcriptomics and proteomics are increasingly applied to gain a mechanistic insight into neurodegenerative disorders. These techniques not only identify distinct, differentially expressed mRNAs and proteins but are also employed to dissect signaling pathways and reveal networks by using an integrated approach. In part I of this back-to-back review, technical aspects are discussed: in the transcriptomics section, which includes enrichment by laser microcapture dissection, we comment on qRT-PCR, SAGE, subtractive hybridization, differential display and microarrays, including software packages. In the proteomics section we discuss two-dimensional (2D) gel electrophoresis, liquid chromatography, methods to label and enrich specific proteins or peptides, and different types of mass spectrometers. These tools have been applied to a range of neurodegenerative disorders and are discussed and integrated in part II (Functional Genomics meets neurodegenerative disorders. Part II: application and data integration).