scholarly journals ConVarT: a search engine for orthologous variants and functional inference of human genetic variants

2021 ◽  
Author(s):  
Mustafa S. Pir ◽  
Halil I. Bilgin ◽  
Ahmet Sayici ◽  
Fatih Coskun ◽  
Furkan M. Torun ◽  
...  

The availability of genetic variants, together with phenotypic annotations from model organisms, facilitates comparing these variants with equivalent variants in humans. However, existing databases and search tools do not make it easy to scan for equivalent variants, namely orthologous variants, between humans and other organisms. Therefore, we developed an integrated search engine called ConVarT (http://www.convart.org/) for orthologous variants between humans, mice, and C. elegans. ConVarT incorporates annotations (including phenotypic and pathogenic) into variants, and these previously unexploited phenotypic OrthoVars from mice and C. elegans can give clues about the functional consequence of human genetic variants. Our analysis shows that many phenotypic variants in different genes from mice and C. elegans, so far, have no counterparts in humans, and thus, can be useful resources when evaluating a relationship between a new human mutation and a disease.

2020 ◽  
Author(s):  
Helena Rawsthorne ◽  
Fernando Calahorro ◽  
Emily Feist ◽  
Lindy Holden-Dye ◽  
Vincent O’Connor ◽  
...  

Abstract Autism spectrum disorder (ASD) is characterized by a triad of behavioural impairments including social behaviour. Neuroligin, a trans-synaptic adhesion molecule, has emerged as a penetrant genetic determinant of behavioural traits that signature the neuroatypical behaviours of autism. However, the function of neuroligin in social circuitry and the impact of genetic variation to this gene is not fully understood. Indeed, in animal studies designed to model autism, there remains controversy regarding the role of neuroligin dysfunction in the expression of disrupted social behaviours. The model organism, Caenorhabditis elegans, offers an informative experimental platform to investigate the impact of genetic variants on social behaviour. In a number of paradigms, it has been shown that inter-organismal communication by chemical cues regulates C. elegans social behaviour. We utilize this social behaviour to investigate the effect of autism-associated genetic variants within the social domain of the research domain criteria. We have identified neuroligin as an important regulator of social behaviour and segregate the importance of this gene to the recognition and/or processing of social cues. We also use CRISPR/Cas9 to edit an R-C mutation that mimics a highly penetrant human mutation associated with autism. C. elegans carrying this mutation phenocopy the behavioural dysfunction of a C. elegans neuroligin null mutant, thus confirming its significance in the regulation of animal social biology. This highlights that quantitative behaviour and precision genetic intervention can be used to manipulate discrete social circuits of the worm to provide further insight into complex social behaviour.


Author(s):  
Helena Rawsthorne ◽  
Fernando Calahorro ◽  
Emily Feist ◽  
Lindy Holden-Dye ◽  
Vincent O’Connor ◽  
...  

AbstractAutism spectrum disorder (ASD) is characterised by a triad of behavioural impairments including social behaviour. Neuroligin, a trans-synaptic adhesion molecule, has emerged as a penetrant genetic determinant of behavioural traits that signature the neuroatypical behaviours of autism. However, the function of neuroligin in social circuitry and the impact of genetic variation to this gene is not fully understood. Indeed, in animal studies designed to model autism there remains controversy regarding the role of neuroligin dysfunction in the expression of disrupted social behaviours. The model organism, C. elegans, offers an informative experimental platform to investigate the impact of genetic variants on social behaviour. In a number of paradigms it has been shown that inter-organismal communication by chemical cues regulates C. elegans social behaviour. We utilise this social behaviour to investigate the effect of autism associated genetic variants within the social domain of the research domain criteria. We have identified neuroligin as an important regulator of social behaviour and segregate the importance of this gene to the recognition and/or processing of social cues. We also use CRISPR/Cas9 to edit an R-C mutation that mimics a highly penetrant human mutation associated with autism. C. elegans carrying this mutation phenocopy the behavioural dysfunction of a C. elegans neuroligin null mutant, thus confirming its significance in the regulation of animal social biology. This highlights that quantitative behaviour and precision genetic intervention can be used to manipulate discrete social circuits of the worm to provide further insight to complex social behaviour.


2002 ◽  
Vol 69 ◽  
pp. 117-134 ◽  
Author(s):  
Stuart M. Haslam ◽  
David Gems ◽  
Howard R. Morris ◽  
Anne Dell

There is no doubt that the immense amount of information that is being generated by the initial sequencing and secondary interrogation of various genomes will change the face of glycobiological research. However, a major area of concern is that detailed structural knowledge of the ultimate products of genes that are identified as being involved in glycoconjugate biosynthesis is still limited. This is illustrated clearly by the nematode worm Caenorhabditis elegans, which was the first multicellular organism to have its entire genome sequenced. To date, only limited structural data on the glycosylated molecules of this organism have been reported. Our laboratory is addressing this problem by performing detailed MS structural characterization of the N-linked glycans of C. elegans; high-mannose structures dominate, with only minor amounts of complex-type structures. Novel, highly fucosylated truncated structures are also present which are difucosylated on the proximal N-acetylglucosamine of the chitobiose core as well as containing unusual Fucα1–2Gal1–2Man as peripheral structures. The implications of these results in terms of the identification of ligands for genomically predicted lectins and potential glycosyltransferases are discussed in this chapter. Current knowledge on the glycomes of other model organisms such as Dictyostelium discoideum, Saccharomyces cerevisiae and Drosophila melanogaster is also discussed briefly.


Author(s):  
Julia Markowski ◽  
Rieke Kempfer ◽  
Alexander Kukalev ◽  
Ibai Irastorza-Azcarate ◽  
Gesa Loof ◽  
...  

Abstract Motivation Genome Architecture Mapping (GAM) was recently introduced as a digestion- and ligation-free method to detect chromatin conformation. Orthogonal to existing approaches based on chromatin conformation capture (3C), GAM’s ability to capture both inter- and intra-chromosomal contacts from low amounts of input data makes it particularly well suited for allele-specific analyses in a clinical setting. Allele-specific analyses are powerful tools to investigate the effects of genetic variants on many cellular phenotypes including chromatin conformation, but require the haplotypes of the individuals under study to be known a-priori. So far however, no algorithm exists for haplotype reconstruction and phasing of genetic variants from GAM data, hindering the allele-specific analysis of chromatin contact points in non-model organisms or individuals with unknown haplotypes. Results We present GAMIBHEAR, a tool for accurate haplotype reconstruction from GAM data. GAMIBHEAR aggregates allelic co-observation frequencies from GAM data and employs a GAM-specific probabilistic model of haplotype capture to optimise phasing accuracy. Using a hybrid mouse embryonic stem cell line with known haplotype structure as a benchmark dataset, we assess correctness and completeness of the reconstructed haplotypes, and demonstrate the power of GAMIBHEAR to infer accurate genome-wide haplotypes from GAM data. Availability GAMIBHEAR is available as an R package under the open source GPL-2 license at https://bitbucket.org/schwarzlab/gamibhear Maintainer [email protected] Supplementary information Supplementary information is available at Bioinformatics online.


2012 ◽  
Vol 6 ◽  
pp. BBI.S9902 ◽  
Author(s):  
Divya P. Syamaladevi ◽  
Margaret S Sunitha ◽  
S. Kalaimathy ◽  
Chandrashekar C. Reddy ◽  
Mohammed Iftekhar ◽  
...  

Myosins are one of the largest protein superfamilies with 24 classes. They have conserved structural features and catalytic domains yet show huge variation at different domains resulting in a variety of functions. Myosins are molecules driving various kinds of cellular processes and motility until the level of organisms. These are ATPases that utilize the chemical energy released by ATP hydrolysis to bring about conformational changes leading to a motor function. Myosins are important as they are involved in almost all cellular activities ranging from cell division to transcriptional regulation. They are crucial due to their involvement in many congenital diseases symptomatized by muscular malfunctions, cardiac diseases, deafness, neural and immunological dysfunction, and so on, many of which lead to death at an early age. We present Myosinome, a database of selected myosin classes (myosin II, V, and VI) from five model organisms. This knowledge base provides the sequences, phylogenetic clustering, domain architectures of myosins and molecular models, structural analyses, and relevant literature of their coiled-coil domains. In the current version of Myosinome, information about 71 myosin sequences belonging to three myosin classes (myosin II, V, and VI) in five model organisms ( Homo Sapiens, Mus musculus, D. melanogaster, C. elegans and S. cereviseae) identified using bioinformatics surveys are presented, and several of them are yet to be functionally characterized. As these proteins are involved in congenital diseases, such a database would be useful in short-listing candidates for gene therapy and drug development. The database can be accessed from http://caps.ncbs.res.in/myosinome .


2020 ◽  
Author(s):  
Jennifer E. Hewitt ◽  
Ricardo Laranjeiro ◽  
Masoud Norouzi ◽  
Rebecca Ellwood ◽  
Adam Antebi ◽  
...  

ABSTRACTDetermining the physical performance of humans using several measures is essential to evaluating the severity of diseases, understanding the role of environmental factors, and developing therapeutic interventions. Development of analogous measures of physical performance in model organisms can help in identifying conserved signaling pathways and prioritizing drug candidates. In this study, we propose a multi-environment phenotyping (MEP) approach that generates a comprehensive set of measures indicative of physical performance in C. elegans. We challenge C. elegans in different mechanical environments of burrowing, swimming, and crawling, each of which places different physiological demands on the animals to generate locomotory forces. Implementation of the MEP approach is done using three established assays corresponding to each environment–a hydrogel-based burrowing assay, the CeleST swim assay, and the NemaFlex crawling strength assay. Using this approach, we study individuals and show that these three assays report on unique aspects of nematode physiology, as phenotypic measures obtained from different environments do not correlate with one another. Analysis of a subset of genes representative of oxidative stress, glucose metabolism, and fat metabolism show differential expression depending on the animal’s environment, suggesting that each environment evokes a response with distinct genetic requirements. To demonstrate the utility of the MEP platform, we evaluate the response of a muscular dystrophy model of C. elegans dys-1 to drug interventions of prednisone, melatonin and serotonin. We find that prednisone, which is the current treatment standard for human Duchenne muscular dystrophy, confers benefits in all three assays. Furthermore, while the tested compounds improve the physical performance of dys-1, these compounds are not able to fully restore the measures to wild-type levels, suggesting the need for discovery efforts to identify more efficacious compounds that could be aided using the MEP platform. In summary, the MEP platform’s ability to robustly define C. elegans locomotory phenotypes demonstrates the utility of the MEP approach toward identification of candidates for therapeutic intervention, especially in disease models in which the neuromuscular performance is impaired.


2015 ◽  
Vol 1 ◽  
pp. e33 ◽  
Author(s):  
Elisha D. Roberson

CRISPR/Cas9 is emerging as one of the most-used methods of genome modification in organisms ranging from bacteria to human cells. However, the efficiency of editing varies tremendously site-to-site. A recent report identified a novel motif, called the 3′GG motif, which substantially increases the efficiency of editing at all sites tested inC. elegans. Furthermore, they highlighted that previously published gRNAs with high editing efficiency also had this motif. I designed a Python command-line tool, ngg2, to identify 3′GG gRNA sites from indexed FASTA files. As a proof-of-concept, I screened for these motifs in six model genomes:Saccharomyces cerevisiae,Caenorhabditis elegans,Drosophila melanogaster,Danio rerio,Mus musculus, andHomo sapiens. I also scanned the genomes of pig (Sus scrofa) and African elephant (Loxodonta africana) to demonstrate the utility in non-model organisms. I identified more than 60 million single match 3′GG motifs in these genomes. Greater than 61% of all protein coding genes in the reference genomes had at least one unique 3′GG gRNA site overlapping an exon. In particular, more than 96% of mouse and 93% of human protein coding genes have at least one unique, overlapping 3′GG gRNA. These identified sites can be used as a starting point in gRNA selection, and the ngg2 tool provides an important ability to identify 3′GG editing sites in any species with an available genome sequence.


eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Andrea Cuentas-Condori ◽  
Ben Mulcahy ◽  
Siwei He ◽  
Sierra Palumbos ◽  
Mei Zhen ◽  
...  

Dendritic spines are specialized postsynaptic structures that transduce presynaptic signals, are regulated by neural activity and correlated with learning and memory. Most studies of spine function have focused on the mammalian nervous system. However, spine-like protrusions have been reported in C. elegans (Philbrook et al., 2018), suggesting that the experimental advantages of smaller model organisms could be exploited to study the biology of dendritic spines. Here, we used super-resolution microscopy, electron microscopy, live-cell imaging and genetics to show that C. elegans motor neurons have functional dendritic spines that: (1) are structurally defined by a dynamic actin cytoskeleton; (2) appose presynaptic dense projections; (3) localize ER and ribosomes; (4) display calcium transients triggered by presynaptic activity and propagated by internal Ca++ stores; (5) respond to activity-dependent signals that regulate spine density. These studies provide a solid foundation for a new experimental paradigm that exploits the power of C. elegans genetics and live-cell imaging for fundamental studies of dendritic spine morphogenesis and function.


2009 ◽  
Vol 284 (24) ◽  
pp. 16482-16491 ◽  
Author(s):  
Julia Sämann ◽  
Jan Hegermann ◽  
Erika von Gromoff ◽  
Stefan Eimer ◽  
Ralf Baumeister ◽  
...  

Mutations in two genes encoding the putative kinases LRRK2 and PINK1 have been associated with inherited variants of Parkinson disease. The physiological role of both proteins is not known at present, but studies in model organisms have linked their mutants to distinct aspects of mitochondrial dysfunction, increased vulnerability to oxidative and endoplasmic reticulum stress, and intracellular protein sorting. Here, we show that a mutation in the Caenorhabditits elegans homologue of the PTEN-induced kinase pink-1 gene resulted in reduced mitochondrial cristae length and increased paraquat sensitivity of the nematode. Moreover, the mutants also displayed defects in axonal outgrowth of a pair of canal-associated neurons. We demonstrate that in the absence of lrk-1, the C. elegans homologue of human LRRK2, all phenotypic aspects of pink-1 loss-of-function mutants were suppressed. Conversely, the hypersensitivity of lrk-1 mutant animals to the endoplasmic reticulum stressor tunicamycin was reduced in a pink-1 mutant background. These results provide the first evidence of an antagonistic role of PINK-1 and LRK-1. Due to the similarity of the C. elegans proteins to human LRRK2 and PINK1, we suggest a common role of both factors in cellular functions including stress response and regulation of neurite outgrowth. This study might help to link pink-1/PINK1 and lrk-1/LRRK2 function to the pathological processes resulting from Parkinson disease-related mutants in both genes, the first manifestations of which are cytoskeletal defects in affected neurons.


2012 ◽  
Vol 40 (4) ◽  
pp. 656-660 ◽  
Author(s):  
Jeanna M. Wheeler ◽  
Chris R. Guthrie ◽  
Brian C. Kraemer

Tauopathies are neurodegenerative diseases, including AD (Alzheimer's disease) and FTLD-T (tau-positive frontotemporal lobar degeneration), with shared pathology presenting as accumulation of detergent-insoluble hyperphosphorylated tau deposits in the central nervous system. The currently available treatments for AD address only some of the symptoms, and do not significantly alter the progression of the disease, namely the development of protein aggregates and loss of functional neurons. The development of effective treatments for various tauopathies will require the identification of common mechanisms of tau neurotoxicity, and pathways that can be modulated to protect against neurodegeneration. Model organisms, such as Caenorhabditis elegans, provide methods for identifying novel genes and pathways that are involved in tau pathology and may be exploited for treatment of various tauopathies. In the present paper, we summarize data regarding characterization of MSUT2 (mammalian suppressor of tau pathology 2), a protein identified in a C. elegans tauopathy model and subsequently shown to modify tau toxicity in mammalian cell culture via the effects on autophagy pathways. MSUT2 represents a potential drug target for prevention of tau-related neurodegeneration.


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