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KLHL20 is part of a CUL3-RING E3 ubiquitin ligase involved in protein ubiquitination. KLHL20 functions as the substrate adaptor that recognizes substrates and mediates the transfer of ubiquitin to the substrates. Although KLHL20 regulates neurite outgrowth and synaptic development in animal models, a role in human neurodevelopment has not yet been described. We report on a neurodevelopmental disorder caused by de novo missense variants in KLHL20.Patients were ascertained by the investigators through Matchmaker Exchange. Phenotyping of patients with de novo missense variants in KLHL20 was performed.We studied 14 patients with de novo missense variants in KLHL20, delineating a genetic syndrome with patients having mild to severe intellectual disability, febrile seizures or epilepsy, autism spectrum disorder, hyperactivity, and subtle dysmorphic facial features. We observed a recurrent de novo missense variant in 11 patients (NM_014458.4:c.1069GA p.[Gly357Arg]). The recurrent missense and the 3 other missense variants all clustered in the Kelch-type β-propeller domain of the KLHL20 protein, which shapes the substrate binding surface.Our findings implicate KLHL20 in a neurodevelopmental disorder characterized by intellectual disability, febrile seizures or epilepsy, autism spectrum disorder, and hyperactivity.

Obesity is a chronic disease affecting millions of people worldwide. The fruit fly (Drosophila melanogaster) is an interesting research model to study metabolic and transcriptomic responses to obesogenic diets. However, the sex-specific differences in these responses are still understudied and perhaps underestimated. In this study, we exposed adult male and female Dahomey fruit flies to a standard diet supplemented with sugar, fat, or a combination of both. The exposure to a diet supplemented with 10% sugar and 10% fat efficiently induced an increase in the lipid content in flies, a hallmark for obesity. This increase in the lipid content was more prominent in males, while females displayed significant changes in the glycogen content. The strong effects of the diets on the ovarian size and number of mature oocytes were also present in females exposed to diets supplemented with fat and a combination of fat and sugar. In both males and females, the fat body morphology changed and was associated with an increase in the lipid content of fat cells in response to the diets. The expression of metabolism-related genes also displayed a strong sexually dimorphic response under normal conditions and in response to the sugar and/or fat-supplemented diets. Here, we showed that the exposure of adult fruit flies to an obesogenic diet containing both sugar and fat allowed studying sexual dimorphism in metabolism and the expression of genes regulating metabolism. ispartof: Biomolecules vol:12 issue:1 ispartof: location:Switzerland status: Published online

Parisot et al., [Background]: The rice weevil Sitophilus oryzae is one of the most important agricultural pests, causing extensive damage to cereal in fields and to stored grains. S. oryzae has an intracellular symbiotic relationship (endosymbiosis) with the Gram-negative bacterium Sodalis pierantonius and is a valuable model to decipher host-symbiont molecular interactions., [Results]: We sequenced the Sitophilus oryzae genome using a combination of short and long reads to produce the best assembly for a Curculionidae species to date. We show that S. oryzae has undergone successive bursts of transposable element (TE) amplification, representing 72% of the genome. In addition, we show that many TE families are transcriptionally active, and changes in their expression are associated with insect endosymbiotic state. S. oryzae has undergone a high gene expansion rate, when compared to other beetles. Reconstruction of host-symbiont metabolic networks revealed that, despite its recent association with cereal weevils (30 kyear), S. pierantonius relies on the host for several amino acids and nucleotides to survive and to produce vitamins and essential amino acids required for insect development and cuticle biosynthesis., [Conclusions]: Here we present the genome of an agricultural pest beetle, which may act as a foundation for pest control. In addition, S. oryzae may be a useful model for endosymbiosis, and studying TE evolution and regulation, along with the impact of TEs on eukaryotic genomes., Funding for this project was provided by the Fondation de l’Institut National des Sciences Appliquées-Lyon (INSA-Lyon), the research direction of INSA-Lyon, the Santé des Plantes et Environnement (SPE) department at the Institut National de Recherche pour l'Agriculture, l'Alimentation et l'Environnement (INRAE), the French ANR-10-BLAN-1701 (ImmunSymbArt), the French ANR-13-BSV7-0016-01 (IMetSym), the French ANR-17_CE20_0031_01 (GREEN), and a grant from la Région Rhône-Alpes (France) to AH. RR received funding from the French ANR-17-CE20-0015 (UNLEASH) and the IDEX-Lyon PALSE IMPULSION initiative. The project was also funded by European Regional Development Fund (ERDF) and Ministerio de Ciencia, Innovación y Universidades (Spain) PGC2018-099344-B-I00 to AL, and PID2019-105969GB-I00 to AM and Conselleria d’Educació, Generalitat Valenciana (Spain), grant number PROMETEO/2018/133 to AM. CV-C was a recipient of a fellowship from the Ministerio de Economía y Competitividad (Spain) and a grant from la Région Rhône-Alpes (France).

The Transient Receptor Potential Ankyrin 1 (TRPA1) cation channels function as broadly-tuned sensors of noxious chemicals in many species. Recent studies identified four functional TRPA1 isoforms in Drosophila melanogaster (dTRPA1(A) to (D)), but their responses to non-electrophilic chemicals are yet to be fully characterized. Methods: We determined the behavioral responses of adult flies to the mammalian TRPA1 non-electrophilic activators citronellal and menthol, and characterized the effects of these compounds on all four dTRPA1 channel isoforms using intracellular Ca2+ imaging and whole-cell patch-clamp recordings. Results: Wild type flies avoided citronellal and menthol in an olfactory test and this behavior was reduced in dTrpA1 mutant flies. Both compounds activate all dTRPA1 isoforms in the heterologous expression system HEK293T, with the following sensitivity series: dTRPA1(C) = dTRPA1(D) > dTRPA1(A) ≫ dTRPA1(B) for citronellal and dTRPA1(A) > dTRPA1(D) > dTRPA1(C) > dTRPA1(B) for menthol. Conclusions: dTrpA1 was required for the normal avoidance of Drosophila melanogaster towards citronellal and menthol. All dTRPA1 isoforms are activated by both compounds, but the dTRPA1(B) is consistently the least sensitive. We discuss how these findings may guide further studies on the physiological roles and the structural bases of chemical sensitivity of TRPA1 channels.

The insulin-producing cells (IPCs), a group of 14 neurons in the Drosophila brain, regulate numerous processes, including energy homeostasis, lifespan, stress response, fecundity, and various behaviors, such as foraging and sleep. Despite their importance, little is known about the development and the factors that regulate morphological and functional differentiation of IPCs. In this study, we describe the use of a new transgenic reporter to characterize the role of the Drosophila L1-CAM homolog Neuroglian (Nrg), and the transmembrane Semaphorin-1a (Sema-1a) and its receptor Plexin A (PlexA) in the differentiation of the insulin-producing neurons. Loss of Nrg results in defasciculation and abnormal neurite branching, including ectopic neurites in the IPC neurons. Cell-type specific RNAi knockdown experiments reveal that Nrg, Sema-1a and PlexA are required in IPCs and glia to control normal morphological differentiation of IPCs albeit with a stronger contribution of Nrg and Sema-1a in glia and of PlexA in the IPCs. These observations provide new insights into the development of the IPC neurons and identify a novel role for Sema-1a in glia. In addition, we show that Nrg, Sema-1a and PlexA in glia and IPCs not only regulate morphological but also functional differentiation of the IPCs and that the functional deficits are likely independent of the morphological phenotypes. The requirements of nrg, Sema-1a, and PlexA in IPC development and the expression of their vertebrate counterparts in the hypothalamic-pituitary axis, suggest that these functions may be evolutionarily conserved in the establishment of vertebrate endocrine systems.

The neprilysin (M13) family of metalloendopeptidases comprises highly conserved ectoenzymes that cleave and thereby inactivate many physiologically relevant peptides in the extracellular space. Impaired neprilysin activity is associated with numerous human diseases. Here, we present a comprehensive list and classification of M13 family members in Drosophila melanogaster. Seven Neprilysin (Nep) genes encode active peptidases, while 21 Neprilysin-like (Nepl) genes encode proteins predicted to be catalytically inactive. RNAseq data demonstrate that all 28 genes are expressed during development, often in a tissue-specific pattern. Most Nep proteins possess a transmembrane domain, whereas almost all Nepl proteins are predicted to be secreted.

International audience; Les membres de la superfamille de l'insuline activent la voie de signalisation évolutive hautement conservée de l'insuline/du facteur de croissance analogue à l'insuline, impliquée dans la régulation de la croissance, de l'homéostasie énergétique et de la longévité. Dans la présente étude, nous nous concentrons sur les pucerons pour mieux comprendre l'évolution des IRP et comment ils peuvent contribuer à la régulation de la voie de signalisation de l'insuline. En utilisant la dernière annotation du génome du puceron du pois (Acyrthosiphon pisum) et en combinant des alignements de séquences et des analyses phylogénétiques, nous avons identifié sept gènes codant pour IRP putatifs, avec IRP1-IRP4 ressemblant aux structures classiques de l'insuline et des protéines analogues à l'insuline, et IRP5 et IRP6 présentant des caractéristiques du facteur de croissance analogue à l'insuline (IGF). Nous avons également identifié IRP11 comme une nouvelle IRP structurellement divergente présente dans au moins huit génomes de pucerons. Globalement, les dix génomes de pucerons analysés dans ce travail contiennent de quatre à 15 IRP, et seuls trois IRP ont été trouvés dans le génome du phylloxéra de la vigne, un insecte hémiptère représentant une branche évolutive antérieure du groupe des pucerons. Les analyses d'expression ont révélé une variation spatiale et temporelle dans les modèles d'expression des différents IRP d'A. pisum. IRP1 et IRP4 sont exprimés à tous les stades de développement et se transforment dans les cellules neuroendocrines du cerveau, tandis que IRP5 et IRP6 sont exprimés dans le corps gras. IRP2 est exprimé dans des cellules spécifiques de l'intestin chez les pucerons dans des conditions non surpeuplées et dans la tête des pucerons dans des conditions surpeuplées, IRP3 dans les glandes salivaires et IRP2 et IRP3 dans la forme mâle. L'expression d'IRP11 est enrichie dans la carcasse. Ce modèle d'expression spatio-temporel complexe suggère une diversification fonctionnelle des IRP.

BackgroundThe rice weevil Sitophilus oryzae is one of the most important agricultural pests, causing extensive damage to cereal in fields and to stored grains. S. oryzae has an intracellular symbiotic relationship (endosymbiosis) with the Gram-negative bacterium Sodalis pierantonius and is a valuable model to decipher host-symbiont molecular interactions.ResultsWe sequenced the Sitophilus oryzae genome using a combination of short and long reads to produce the best assembly for a Curculionidae species to date. We show that S. oryzae has undergone successive bursts of transposable element (TE) amplification, representing 72% of the genome. In addition, we show that many TE families are transcriptionally active, and changes in their expression are associated with insect endosymbiotic state. S. oryzae has undergone a high gene expansion rate, when compared to other beetles. Reconstruction of host-symbiont metabolic networks revealed that, despite its recent association with cereal weevils (30 Kyear), S. pierantonius relies on the host for several amino acids and nucleotides to survive and to produce vitamins and essential amino-acids required for insect development and cuticle biosynthesis.ConclusionsHere we present the genome of an agricultural pest beetle, which may act as a foundation for pest control. In addition, S. oryzae may be a useful model for endosymbiosis, and studying TE evolution and regulation, along with the impact of TEs on eukaryotic genomes.

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Significance Apoptotic processes play an important role in the development and physiology of almost all metazoan clades. In the highly diverse group of insects, apoptotic pathways have been characterized in only a few dipteran and lepidopteran species, which may not be representative of all insect species. Here, we report the first complete annotation of the apoptotic pathway in a hemipteran insect, the pea aphid Acyrthosiphon pisum. We showed that its apoptotic pathway is rewired compared to other insects, with a significant increase in the number of inhibitors of apoptosis (IAPs) and evidence for functional diversification and structural modularity of this protein family. These novelties are widespread in the aphid lineage, suggesting a yet not understood novel aphid-specific function of IAPs., Apoptosis, a conserved form of programmed cell death, shows interspecies differences that may reflect evolutionary diversification and adaptation, a notion that remains largely untested. Among insects, the most speciose animal group, the apoptotic pathway has only been fully characterized in Drosophila melanogaster, and apoptosis-related proteins have been studied in a few other dipteran and lepidopteran species. Here, we studied the apoptotic pathway in the aphid Acyrthosiphon pisum, an insect pest belonging to the Hemiptera, an earlier-diverging and distantly related order. We combined phylogenetic analyses and conserved domain identification to annotate the apoptotic pathway in A. pisum and found low caspase diversity and a large expansion of its inhibitory part, with 28 inhibitors of apoptosis (IAPs). We analyzed the spatiotemporal expression of a selected set of pea aphid IAPs and showed that they are differentially expressed in different life stages and tissues, suggesting functional diversification. Five IAPs are specifically induced in bacteriocytes, the specialized cells housing symbiotic bacteria, during their cell death. We demonstrated the antiapoptotic role of these five IAPs using heterologous expression in a tractable in vivo model, the Drosophila melanogaster developing eye. Interestingly, IAPs with the strongest antiapoptotic potential contain two BIR and two RING domains, a domain association that has not been observed in any other species. We finally analyzed all available aphid genomes and found that they all show large IAP expansion, with new combinations of protein domains, suggestive of evolutionarily novel aphid-specific functions.

Social impairment is frequently associated with mitochondrial dysfunction and altered neurotransmission. Although mitochondrial function is crucial for brain homeostasis, it remains unknown whether mitochondrial disruption contributes to social behavioral deficits. Here, we show that Drosophila mutants in the homolog of the human CYFIP1, a gene linked to autism and schizophrenia, exhibit mitochondrial hyperactivity and altered group behavior. We identify the regulation of GABA availability by mitochondrial activity as a biologically relevant mechanism and demonstrate its contribution to social behavior. Specifically, increased mitochondrial activity causes gamma aminobutyric acid (GABA) sequestration in the mitochondria, reducing GABAergic signaling and resulting in social deficits. Pharmacological and genetic manipulation of mitochondrial activity or GABA signaling corrects the observed abnormalities. We identify Aralar as the mitochondrial transporter that sequesters GABA upon increased mitochondrial activity. This study increases our understanding of how mitochondria modulate neuronal homeostasis and social behavior under physiopathological conditions. ispartof: CELL vol:180 issue:6 pages:1178-+ ispartof: location:United States status: published

Background Neuropsychiatric lupus (NPSLE) refers to the neurological and psychiatric manifestations that are commonly observed in patients with systemic lupus erythematosus (SLE). An important question regarding the pathogenesis of NPSLE is whether the symptoms are caused primarily by CNS-intrinsic mechanisms or develop as a consequence of systemic autoimmunity. Currently used spontaneous mouse models for SLE have already contributed significantly to unraveling how systemic immunity affects the CNS. However, they are less suited when interested in CNS primary mechanisms. In addition, none of these models are based on genes that are associated with SLE. In this study, we evaluate the influence of A20, a well-known susceptibility locus for SLE, on behavior and CNS-associated changes in inflammatory markers. Furthermore, given the importance of environmental triggers for disease onset and progression, the influence of an acute immunological challenge was evaluated. Methods Female and male A20 heterozygous mice (A20+/−) and wildtype littermates were tested in an extensive behavioral battery. This was done at the age of 10±2weeks and 24 ​± ​2 weeks to evaluate the impact of aging. To investigate the contribution of an acute immunological challenge, LPS was injected intracerebroventricularly at the age of 10±2weeks followed by behavioral analysis. Underlying molecular mechanisms were evaluated in gene expression assays on hippocampus and cortex. White blood cell count and blood-brain barrier permeability were analyzed to determine whether peripheral inflammation is a relevant factor. Results A20 heterozygosity predisposes to cognitive symptoms that were observed at the age of 10 ​± ​2 weeks and 24 ​± ​2 weeks. Young A20+/− males and females showed a subtle cognitive phenotype (10±2weeks) with distinct neuroinflammatory phenotypes. Aging was associated with clear neuroinflammation in female A20+/− mice only. The genetic predisposition in combination with an environmental stimulus exacerbates the behavioral impairments related to anxiety, cognitive dysfunction and sensorimotor gating. This was predominantly observed in females. Furthermore, signs of neuroinflammation were solely observed in female A20+/− mice. All above observations were made in the absence of peripheral inflammation and of changes in blood-brain barrier permeability, thus consistent with the CNS-primary hypothesis. Conclusions We show that A20 heterozygosity is a predisposing factor for NPSLE. Further mechanistic insight and possible therapeutic interventions can be studied in this mouse model that recapitulates several key hallmarks of the disease., Highlights • A novel mouse model for neuropsychiatric lupus was established. • Loss of 1 copy of A20/TNFAIP3 leads to neuroinflammation and cognitive symptoms. • Female-specific neuroinflammation was seen with age. • An environmental stimulus worsens the behavioral impairments. • The results show that the brain is the primary affected site.

Cardiovascular disease associated with metabolic syndrome has a high prevalence, but the mechanistic basis of metabolic cardiomyopathy remains poorly understood. We characterised the cardiac transcriptome in a murine metabolic syndrome (MetS) model (LDLR-/-; ob/ob, DKO) relative to the healthy, control heart (C57BL/6, WT) and the transcriptional changes induced by ACE-inhibition in those hearts. RNA-Seq, differential gene expression and transcription factor analysis identified 288 genes differentially expressed between DKO and WT hearts implicating 72 pathways. Hallmarks of metabolic cardiomyopathy were increased activity in integrin-linked kinase signalling, Rho signalling, dendritic cell maturation, production of nitric oxide and reactive oxygen species in macrophages, atherosclerosis, LXR-RXR signalling, cardiac hypertrophy, and acute phase response pathways. ACE-inhibition had a limited effect on gene expression in WT (55 genes, 23 pathways), and a prominent effect in DKO hearts (1143 genes, 104 pathways). In DKO hearts, ACE-I appears to counteract some of the MetS-specific pathways, while also activating cardioprotective mechanisms. We conclude that MetS and control murine hearts have unique transcriptional profiles and exhibit a partially specific transcriptional response to ACE-inhibition. ispartof: SCIENTIFIC REPORTS vol:8 issue:1 ispartof: location:England status: published

Summary RNA-binding protein aggregation is a pathological hallmark of several neurodegenerative disorders, including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). To gain better insight into the molecular interactions underlying this process, we investigated FUS, which is mutated and aggregated in both ALS and FTLD. We generated a Drosophila model of FUS toxicity and identified a previously unrecognized synergistic effect between the N-terminal prion-like domain and the C-terminal arginine-rich domain to mediate toxicity. Although the prion-like domain is generally considered to mediate aggregation of FUS, we find that arginine residues in the C-terminal low-complexity domain are also required for maturation of FUS in cellular stress granules. These data highlight an important role for arginine-rich domains in the pathology of RNA-binding proteins., Graphical Abstract, Highlights • Both QGSY and RGG2 domains are necessary for FUS-induced neurodegeneration in flies • Arginine-rich domains interact with QGSY hydrogels and liquid droplets • RGG2 arginines promote phase separation of FUS in vitro and in cells • FUS phase separation behavior in vitro correlates with neurodegeneration in vivo, Protein aggregation is a hallmark of ALS. Bogaert et al. describe the molecular interactions between disordered regions of the FUS protein driving its liquid phase behavior, maturation, and neurotoxicity. These findings highlight the physicochemical interactions driving FUS phase separation and give us insights into its misregulation in disease.

Background: The transient receptor potential ankyrin 1 (TRPA1) cation channels function as broadly-tuned sensors of noxious chemicals in many species. Recent studies identified four functional TRPA1 isoforms in Drosophila melanogaster (dTRPA1(A) to (D)), but their responses to non-electrophilic chemicals are yet to be fully characterized. Methods: We determined the behavioral responses of adult flies to the mammalian TRPA1 non-electrophilic activators citronellal and menthol, and characterized the effects of these compounds on all four dTRPA1 channel isoforms using intracellular Ca2+ imaging and whole-cell patch-clamp recordings. Results: Wild type flies avoided citronellal and menthol in an olfactory test and this behavior was reduced in dTrpA1 mutant flies. Both compounds activate all dTRPA1 isoforms in the heterologous expression system HEK293T, with the following sensitivity series: dTRPA1(C) = dTRPA1(D) &gt, dTRPA1(A) ≫ dTRPA1(B) for citronellal and dTRPA1(A) &gt, dTRPA1(D) &gt, dTRPA1(C) &gt, dTRPA1(B) for menthol. Conclusions: dTrpA1 was required for the normal avoidance of Drosophila melanogaster towards citronellal and menthol. All dTRPA1 isoforms are activated by both compounds, but the dTRPA1(B) is consistently the least sensitive. We discuss how these findings may guide further studies on the physiological roles and the structural bases of chemical sensitivity of TRPA1 channels.

Significance Comparative developmental genetics indicate insect and mammalian forebrains form and function in comparable ways. However, these data are open to opposing interpretations that advocate either a single origin of the brain and its adaptive modification during animal evolution; or multiple, independent origins of the many different brains present in extant Bilateria. Here, we describe conserved regulatory elements that mediate the spatiotemporal expression of developmental control genes directing the formation and function of midbrain circuits in flies, mice, and humans. These circuits develop from corresponding midbrain-hindbrain boundary regions and regulate comparable behaviors for balance and motor control. Our findings suggest that conserved regulatory mechanisms specify cephalic circuits for sensory integration and coordinated behavior common to all animals that possess a brain., Corresponding attributes of neural development and function suggest arthropod and vertebrate brains may have an evolutionarily conserved organization. However, the underlying mechanisms have remained elusive. Here, we identify a gene regulatory and character identity network defining the deutocerebral–tritocerebral boundary (DTB) in Drosophila. This network comprises genes homologous to those directing midbrain-hindbrain boundary (MHB) formation in vertebrates and their closest chordate relatives. Genetic tracing reveals that the embryonic DTB gives rise to adult midbrain circuits that in flies control auditory and vestibular information processing and motor coordination, as do MHB-derived circuits in vertebrates. DTB-specific gene expression and function are directed by cis-regulatory elements of developmental control genes that include homologs of mammalian Zinc finger of the cerebellum and Purkinje cell protein 4. Drosophila DTB-specific cis-regulatory elements correspond to regulatory sequences of human ENGRAILED-2, PAX-2, and DACHSHUND-1 that direct MHB-specific expression in the embryonic mouse brain. We show that cis-regulatory elements and the gene networks they regulate direct the formation and function of midbrain circuits for balance and motor coordination in insects and mammals. Regulatory mechanisms mediating the genetic specification of cephalic neural circuits in arthropods correspond to those in chordates, thereby implying their origin before the divergence of deuterostomes and ecdysozoans.

International audience; Aphids are sap-sucking insects that comprise about 5500 species colonizing a wide variety of host plants. They are the dominant group (26%) among insect pests of the six main crops grown for human consumption, with the potential to cause a worldwide economic impact. Aphids inflict damage directly by feeding and indirectly by phytovirus transmission. Since the initial sequencing of the genome of the pea aphid, Acyrthosiphon pisum and its symbiont Buchnera aphidicola, a further 12 aphid genome sequences have become available. Most of these genomes are accessible at the dedicated AphidBasei. Fourteen Buchnera genomes have also been sequenced. This provides a unique opportunity to study selection, adaptation, and evolution using aphids as a model family of species with broad distribution and adaptation to different environments and food sources. In addition, the availability of the genomes will facilitate future comparative studies focusing on the development, physiology, and metabolism of aphids to identify novel pest control strategies.

Aggression is a universal social behavior important for the acquisition of food, mates, territory, and social status. Aggression in Drosophila is context-dependent and can thus be expected to involve inputs from multiple sensory modalities. Here, we use mechanical disruption and genetic approaches in Drosophila melanogaster to identify hearing as an important sensory modality in the context of intermale aggressive behavior. We demonstrate that neuronal silencing and targeted knockdown of hearing genes in the fly’s auditory organ elicit abnormal aggression. Further, we show that exposure to courtship or aggression song has opposite effects on aggression. Our data define the importance of hearing in the control of Drosophila intermale aggression and open perspectives to decipher how hearing and other sensory modalities are integrated at the neural circuit level.

Identification of novel candidate genes for schizophrenia (SZ) and bipolar disorder (BP), two psychiatric disorders with large epidemiological impacts, is a key research area in neurosciences and psychiatric genetics. Previous evidence from genome-wide studies suggests an important role for genes involved in synaptic plasticity in the risk for SZ and BP. We used a convergent genomics approach, combining different lines of biological evidence, to identify genes involved in the cAMP/PKA/CREB functional pathway that could be novel candidates for BP and SZ: CREB1, CREM, GRIN2C, NPY2R, NF1, PPP3CB and PRKAR1A. These 7 genes were analyzed in a HapMap based association study comprising 48 common SNPs in 486 SZ, 351 BP patients and 514 control individuals recruited from an isolated population in Northern Sweden. Genetic analysis showed significant allelic associations of SNPs in PRKAR1A with SZ and of PPP3CB and PRKAR1A with BP. Our results highlight the feasibility and the importance of convergent genomic data analysis for the identification of candidate genes and our data provide support for the role of common inherited variants in synaptic genes and their involvement in the etiology of BP and SZ. (C) 2016 Elsevier B.V. All rights reserved.

International audience; Programmed cell death is an intrinsic part of normal development, physiology and organismal homeostasis. Apoptosis is a widespread form of regulated cell death, controlled by a genetically encoded machinery conserved throughout evolution. In the highly diverse group of insects, apoptotic pathways have been characterized in only a few dipteran and lepidopteran species, where they have been shown to be essential for development, metamorphosis and immunity-related processes. The lack of studies in other insect orders clearly limits our understanding of the role of apoptosis in the life history of insects.

International audience; Apoptosis is a widespread form of regulated cell death, controlled by a genetically-encoded machinery conserved in almost all metazoan clades. In the highly diverse group of insects, apoptotic pathways have been characterized in only a few dipteran and lepidopteran species, where they have been shown to be essential for development, metamorphosis and immunity-related processes. The lack of studies in other insect orders clearly limits our understanding of the role of apoptosis in insects’ lives. In this study, we combined phylogenetic analyses and conserved domain identification to annotate the apoptosis pathway in a hemipteran model: the pea aphid Acyrthosiphon pisum. We found that the executive part of the pathway is incomplete, with homologs for only 4 out of the 8 proteins present in Drosophila melanogaster, while the inhibitory part underwent a large expansion, with over 30 Inhibitor-of-Apoptosis Proteins (IAPs) in contrast to the 4 to 7 found in other insect species. Tissue-specific qRT-PCR and RNAseq analyses have shown that, in senescent aphids, only two apoptotic effectors are induced in bacteriocytes, the specialized cells housing symbiotic bacteria, while several apoptosis inhibitors are concomitantly over-expressed. This provides a possible mechanism whereby apoptosis is prevented in these cells, enabling the emergence of a novel cell death process. We have confirmed the anti-apoptotic role of these bacteriocyte cell death-associated IAPs in heterologous expression experiments using a tractable in vivo model, the drosophila developing eye. These results suggest that a restricted set of aphid IAPs have a key role in bacteriocyte homeostasis. Other aphid IAPs are differentially expressed in different life stages and tissues, suggesting an as yet not understood functional diversification. Interestingly, this IAP functional diversification is expected to also occur in other aphid species as, using comparative phylogenomics analyses, we have demonstrated that IAP expansion is widespread in aphid lineages.

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International audience

International audience; Symbiosis is a key source of ecological and evolutionary diversification of eukaryotic organisms throughout the animal and plant kingdoms. In insects that are obligatorily dependent on intracellular bacterial symbionts, novel host cells, the bacteriocytes, have evolved for harboring beneficial microbial partners. These cells constitute a fascinating riddle in developmental and evolutionary cell biology, as the molecular mechanisms governing their homeostasis in response to host physiology remain largely unsolved. We recently demonstrated that in the pea aphid (Acyrthosiphon pisum) model system, bacteriocytes degenerate through a hitherto unknown process distinct from evolutionarily conserved pathways, including apoptosis- or autophagy-dependent cell deaths (1,2). By combining electron microscopy, immunohistochemistry, and molecular analyses, we showed that the initial event of bacteriocyte cell death is the cytoplasmic accumulation of non-autophagic vacuoles derived from the endoplasmic reticulum. This early process is followed by a sequence of cellular stress responses, spanning aphid adulthood, that include the formation of autophagosomes in intervacuolar spaces and Buchnera aphidicola endosymbiont degradation by the lysosomal system.Interestingly, this mechanism of bacteriocyte degeneration is distinct from the process previously described in other insects. In the recently established symbiotic relationship [dating to less than 0.03 million years (My)] between Sitophilus weevils and the Sodalis pierantonius bacterium, bacteriocytes are totally and rapidly eliminated in young adults by a combination of apoptosis and autophagy (3). Given that bacteriocytes evolved independently in many different insect orders, it remains to be seen whether the bacteriocyte cell death identified in the pea aphid is a conserved mechanisms across insects or is restricted to evolutionary ancient symbioses like aphids and other hemipteran species. In order to understand the mechanisms underlying aphid bacteriocyte cell death, we carefully annotated the apoptosis pathway of A. pisum and studied the expression of apoptosis- and apoptosis inhibitors-related genes. We found that, while the executive pathway of apoptosis is incomplete in the pea aphid, with homologs for only four out of the eight proteins present in Drosophila melanogaster, apoptosis inhibitors underwent a huge gene expansion, with more than 80 inhibitor of apoptosis protein (IAP) homologs annotated. Indeed, in D. melanogaster, only four IAPs have been identified. We were able to classify the A. pisum IAPs in five different classes, based on the presence of different combinations of BIR and RING domains. While only a few apoptotic genes are induced in senescent bacteriocytes, apoptosis inhibitors from three of these classes are concomitantly over-expressed with time, possibly preventing the apoptosis in these cells and thereby delaying their elimination. Phylogenetic analyses showed that this expansion of IAP-encoding genes is widespread in the aphid lineage, even in the ancient, non-symbiotic, phylloxera species that contains 31 IAPs encoding genes. IAP gene expansion has not been found in other insect genomes. Complementary phylogenetic analyses and functional studies are ongoing to understand the role of this gene expansion and of the different IAPs in aphid physiology.(1) Simonet et al (2016) Direct flow cytometry measurements reveal a fine-tuning of symbiotic cell dynamics according to the host developmental needs in aphid symbiosis. Sci Rep. doi: 10.1038/srep19967.(2) Simonet et al (2018) Bacteriocyte cell death in the aphid/Buchnera symbiotic system. PNAS doi: 10.1073/pnas.1720237115.(3) Vigneron et al (2014) Insects recycle endosymbionts when the benefit is over. Curr Biol. doi: 10.1016/j.cub.2014.07.065.

International audience; Symbiosis is a key source of ecological and evolutionary diversification of eukaryotic organisms throughout the animal and plant kingdoms. In insects that are obligatorily dependent on intracellular bacterial symbionts, novel host cells, the bacteriocytes, have evolved for harboring beneficial microbial partners. One of the most fundamental questions concerning these enigmatic cells is how organismal homeostasis controls their numbers and elimination.Here we report that, in the pea aphid, Acyrthosiphon pisum, bacteriocytes degenerate through a hitherto unknown process distinct from evolutionarily conserved pathways, including apoptosis- or autophagy-dependent cell deaths. By combining electron microscopy, immunohistochemistry, and molecular analyses, we demonstrated that the initial event of bacteriocyte cell death is the cytoplasmic accumulation of non-autophagic vacuoles derived from the endoplasmic reticulum, followed by a sequence of cellular stress responses including the formation of autophagosomes in intervacuolar spaces, activation of reactive oxygen species, and Buchnera endosymbiont degradation by the lysosomal system (1). This new cell death process does not seem to affect the other tissues of the insect and is therefore specific to the bacteriocyte cell. It is not activated by caspases, the enzymes involved in triggering and executing apoptosis, whose pathway is incomplete in the pea aphid (2).Our findings reveal novel mechanisms by which bacteriocyte cell and symbiotic bacterial numbers are controlled by organismal homeostasis and shed light on previously unknown aspects of bacteriocyte biological functioning. The discovery of a non-apoptotic and non- autophagic cell-death process in an insect model contributes more broadly to the understanding of metazoan cell-death diversity.(1) Simonet P., Gaget K., Balmand S., Ribeiro-Lopes M., Parisot N., Buhler K., Duport G., Vulsteke V., Febvay G., Heddi A., Charles H., Callaerts P., Calevro F. (2018) Bacteriocyte cell death in the aphid/Buchnera symbiotic system. www.pnas.org/cgi/doi/10.1073/pnas.1720237115. (2) Ribeiro-Lopes M., Simonet P., Gaget K., Duport G., Charles H., Heddi A., Callaerts P., Parisot N., Calevro F. (2017) Effecteurs et inhibiteurs de l’apoptose chez le puceron du pois : annotation et implication dans la mort cellulaire bactériocytaire. 10ème Réunion du Réseau Français de Biologie Adaptative des Pucerons et Organismes Associés (BAPOA), novembre 2017, Colmar, France.

Amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) are neurodegenerative diseases characterized by the progressive loss of specific groups of neurons. Due to clinical, genetic and pathological overlap, both diseases are considered as the extremes of one disease spectrum and in a number of ALS and FTD patients, fused in sarcoma (FUS) aggregates are present. Even in families with a monogenetic disease cause, a striking variability is observed in disease presentation. This suggests the presence of important modifying genes. The identification of disease-modifying genes will contribute to defining clear therapeutic targets and to understanding the pathways involved in motor neuron death. In this study, we established a novel in vivo screening platform in which new modifying genes of FUS toxicity can be identified. Expression of human FUS induced the selective apoptosis of crustacean cardioactive peptide (CCAP) neurons from the ventral nerve cord of fruit flies. No defects in the development of these neurons were observed nor were the regulatory CCAP neurons from the brain affected. We used the number of CCAP neurons from the ventral nerve cord as an in vivo read-out for FUS toxicity in neurons. Via a targeted screen, we discovered a potent modifying role of proteins involved in nucleocytoplasmic transport. Downregulation of Nucleoporin 154 and Exportin1 (XPO1) prevented FUS-induced neurotoxicity. Moreover, we show that XPO1 interacted with FUS. Silencing XPO1 significantly reduced the propensity of FUS to form inclusions upon stress. Taken together, our findings point to an important role of nucleocytoplasmic transport proteins in FUS-induced ALS/FTD. ispartof: HUMAN MOLECULAR GENETICS vol:27 issue:23 pages:1-14 ispartof: location:England status: Published online

Growth and maturation are coordinated processes in all animals. Integration of internal cues, such as signalling pathways, with external cues, such as nutritional status, is paramount for an orderly progression of development and growth. In

Significance Beneficial symbiotic associations, ubiquitously found in nature, have led to the emergence of eukaryotic cells, the bacteriocytes, specialized in harboring microbial partners. One of the most fundamental questions concerning these enigmatic cells is how organismal homeostasis controls their elimination. Here we report that aphid bacteriocytes have evolved a form of cell death distinct from the conserved cell-death mechanisms hitherto characterized. This cell-death mechanism is a nonapoptotic multistep process that starts with the hypervacuolation of the endoplasmic reticulum, followed by a cascade of cellular stress responses. Our findings provide a framework to study biological functioning of bacteriocytes and the cellular mechanisms associated with symbiosis and contribute to the understanding of eukaryotic cell-death diversity., Symbiotic associations play a pivotal role in multicellular life by facilitating acquisition of new traits and expanding the ecological capabilities of organisms. In insects that are obligatorily dependent on intracellular bacterial symbionts, novel host cells (bacteriocytes) or organs (bacteriomes) have evolved for harboring beneficial microbial partners. The processes regulating the cellular life cycle of these endosymbiont-bearing cells, such as the cell-death mechanisms controlling their fate and elimination in response to host physiology, are fundamental questions in the biology of symbiosis. Here we report the discovery of a cell-death process involved in the degeneration of bacteriocytes in the hemipteran insect Acyrthosiphon pisum. This process is activated progressively throughout aphid adulthood and exhibits morphological features distinct from known cell-death pathways. By combining electron microscopy, immunohistochemistry, and molecular analyses, we demonstrated that the initial event of bacteriocyte cell death is the cytoplasmic accumulation of nonautophagic vacuoles, followed by a sequence of cellular stress responses including the formation of autophagosomes in intervacuolar spaces, activation of reactive oxygen species, and Buchnera endosymbiont degradation by the lysosomal system. We showed that this multistep cell-death process originates from the endoplasmic reticulum, an organelle exhibiting a unique reticular network organization spread throughout the entire cytoplasm and surrounding Buchnera aphidicola endosymbionts. Our findings provide insights into the cellular and molecular processes that coordinate eukaryotic host and endosymbiont homeostasis and death in a symbiotic system and shed light on previously unknown aspects of bacteriocyte biological functioning.

International audience; Symbiotic associations play a pivotal role in multicellular life by facilitating acquisition of new traits and expanding the ecological capabilities of organisms. In insects that are obligatorily dependent on intracellular bacterial symbionts, novel host cells (bacteriocytes) or organs (bacteriomes) have evolved for harboring beneficial microbial partners. The processes regulating the cellular life cycle of these endosymbiont-bearing cells, such as the cell-death mechanisms controlling their fate and elimination in response to host physiology, are fundamental questions in the biology of symbiosis. Here we report the discovery of a cell-death process involved in the degeneration of bacteriocytes in the hemipteran insect Acyrthosiphon pisum This process is activated progressively throughout aphid adulthood and exhibits morphological features distinct from known cell-death pathways. By combining electron microscopy, immunohistochemistry, and molecular analyses, we demonstrated that the initial event of bacteriocyte cell death is the cytoplasmic accumulation of nonautophagic vacuoles, followed by a sequence of cellular stress responses including the formation of autophagosomes in intervacuolar spaces, activation of reactive oxygen species, and Buchnera endosymbiont degradation by the lysosomal system. We showed that this multistep cell-death process originates from the endoplasmic reticulum, an organelle exhibiting a unique reticular network organization spread throughout the entire cytoplasm and surrounding Buchnera aphidicola endosymbionts. Our findings provide insights into the cellular and molecular processes that coordinate eukaryotic host and endosymbiont homeostasis and death in a symbiotic system and shed light on previously unknown aspects of bacteriocyte biological functioning.

Microglia, the mononuclear phagocytes of the central nervous system (CNS), are important for the maintenance of CNS homeostasis, but also critically contribute to CNS pathology. Here we demonstrate that the nuclear factor kappa B (NF-κB) regulatory protein A20 is crucial in regulating microglia activation during CNS homeostasis and pathology. In mice, deletion of A20 in microglia increases microglial cell number and affects microglial regulation of neuronal synaptic function. Administration of a sublethal dose of lipopolysaccharide induces massive microglia activation, neuroinflammation, and lethality in mice with microglia-confined A20 deficiency. Microglia A20 deficiency also exacerbates multiple sclerosis (MS)-like disease, due to hyperactivation of the Nlrp3 inflammasome leading to enhanced interleukin-1β secretion and CNS inflammation. Finally, we confirm a Nlrp3 inflammasome signature and IL-1β expression in brain and cerebrospinal fluid from MS patients. Collectively, these data reveal a critical role for A20 in the control of microglia activation and neuroinflammation., As resident macrophages of the brain, microglia are important for neuroinflammatory responses. This work shows that nuclear factor kappa B regulatory protein A20 is important for microglia activation and regulation during inflammation of the central nervous system.

Growth and maturation are coordinated processes in all animals. Integration of internal cues, such as signalling pathways, with external cues such as nutritional status is paramount for an orderly progression of development in function of growth. In Drosophila, this involves insulin and steroid signalling, but the underlying mechanisms and their coordination are incompletely understood. We show that bioactive 20-hydroxyecdysone production by the enzyme Shade in the fat body is a nutrient-dependent process. We demonstrate that under fed conditions, Shade plays a role in growth control. We identify the trachea and the insulin-producing cells in the brain as direct targets through which 20-hydroxyecdysone regulates insulin-signaling. The identification of the trachea-dependent regulation of insulin-signaling exposes an important variable that may have been overlooked in other studies focusing on insulin-signaling in Drosophila. Our findings provide a potentially conserved, novel mechanism by which nutrition can modulate steroid hormone bioactivation, reveal an important caveat of a commonly used transgenic tool to study IPC function and yield further insights as to how steroid and insulin signalling are coordinated during development to regulate growth and developmental timing.