Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 43
Filtrar
1.
J Virol ; 95(12)2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-33827942

RESUMO

Host-pathogen interactions play a major role in evolutionary selection and shape natural genetic variation. The genetically distinct Caenorhabditis elegans strains, Bristol N2 and Hawaiian CB4856, are differentially susceptible to the Orsay virus (OrV). Here, we report the dissection of the genetic architecture of susceptibility to OrV infection. We compare OrV infection in the relatively resistant wild-type CB4856 strain to the more susceptible canonical N2 strain. To gain insight into the genetic architecture of viral susceptibility, 52 fully sequenced recombinant inbred lines (CB4856 × N2 RILs) were exposed to OrV. This led to the identification of two loci on chromosome IV associated with OrV resistance. To verify the two loci and gain additional insight into the genetic architecture controlling virus infection, introgression lines (ILs) that together cover chromosome IV, were exposed to OrV. Of the 27 ILs used, 17 had an CB4856 introgression in an N2 background, and 10 had an N2 introgression in a CB4856 background. Infection of the ILs confirmed and fine-mapped the locus underlying variation in OrV susceptibility, and we found that a single nucleotide polymorphism in cul-6 may contribute to the difference in OrV susceptibility between N2 and CB4856. An allele swap experiment showed the strain CB4856 became as susceptible as the N2 strain by having an N2 cul-6 allele, although having the CB4856 cul-6 allele did not increase resistance in N2. In addition, we found that multiple strains with nonoverlapping introgressions showed a distinct infection phenotype from the parental strain, indicating that there are punctuated locations on chromosome IV determining OrV susceptibility. Thus, our findings reveal the genetic complexity of OrV susceptibility in C. elegans and suggest that viral susceptibility is governed by multiple genes.IMPORTANCE Genetic variation determines the viral susceptibility of hosts. Yet, pinpointing which genetic variants determine viral susceptibility remains challenging. Here, we have exploited the genetic tractability of the model organism Caenorhabditis elegans to dissect the genetic architecture of Orsay virus infection. Our results provide novel insight into natural determinants of Orsay virus infection.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Caenorhabditis elegans/virologia , Cromossomos/genética , Proteínas Culina/genética , Variação Genética , Nodaviridae/patogenicidade , Locos de Características Quantitativas , Animais , Genes de Helmintos , Predisposição Genética para Doença , Interações Hospedeiro-Patógeno , Herança Multifatorial , Nodaviridae/fisiologia , Polimorfismo de Nucleotídeo Único , Carga Viral
2.
Glob Chang Biol ; 25(8): 2714-2726, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31002208

RESUMO

Current climate change has led to latitudinal and altitudinal range expansions of numerous species. During such range expansions, plant species are expected to experience changes in interactions with other organisms, especially with belowground biota that have a limited dispersal capacity. Nematodes form a key component of the belowground food web as they include bacterivores, fungivores, omnivores and root herbivores. However, their community composition under climate change-driven intracontinental range-expanding plants has been studied almost exclusively under controlled conditions, whereas little is known about actual patterns in the field. Here, we use novel molecular sequencing techniques combined with morphological quantification in order to examine nematode communities in the rhizospheres of four range-expanding and four congeneric native species along a 2,000 km latitudinal transect from South-Eastern to North-Western Europe. We tested the hypotheses that latitudinal shifts in nematode community composition are stronger in range-expanding plant species than in congeneric natives and that in their new range, range-expanding plant species accumulate fewest root-feeding nematodes. Our results show latitudinal variation in nematode community composition of both range expanders and native plant species, while operational taxonomic unit richness remained the same across ranges. Therefore, range-expanding plant species face different nematode communities at higher latitudes, but this is also the case for widespread native plant species. Only one of the four range-expanding plant species showed a stronger shift in nematode community composition than its congeneric native and accumulated fewer root-feeding nematodes in its new range. We conclude that variation in nematode community composition with increasing latitude occurs for both range-expanding and native plant species and that some range-expanding plant species may become released from root-feeding nematodes in the new range.


Assuntos
Nematoides , Solo , Animais , Europa (Continente) , Plantas , Rizosfera
3.
Trends Genet ; 31(5): 224-31, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25804345

RESUMO

Model organisms are of great importance to our understanding of basic biology and to making advances in biomedical research. However, the influence of laboratory cultivation on these organisms is underappreciated, and especially how that environment can affect research outcomes. Recent experiments led to insights into how the widely used laboratory reference strain of the nematode Caenorhabditis elegans compares with natural strains. Here we describe potential selective pressures that led to the fixation of laboratory-derived alleles for the genes npr-1, glb-5, and nath-10. These alleles influence a large number of traits, resulting in behaviors that affect experimental interpretations. Furthermore, strong phenotypic effects caused by these laboratory-derived alleles hinder the discovery of natural alleles. We highlight strategies to reduce the influence of laboratory-derived alleles and to harness the full power of C. elegans.


Assuntos
Caenorhabditis elegans/genética , Modelos Animais , Adaptação Biológica/genética , Alelos , Animais , Interação Gene-Ambiente , Variação Genética
4.
Mol Cell Proteomics ; 15(5): 1670-80, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-26944343

RESUMO

Natural genetic variation is the raw material of evolution and influences disease development and progression. An important question is how this genetic variation translates into variation in protein abundance. To analyze the effects of the genetic background on gene and protein expression in the nematode Caenorhabditis elegans, we quantitatively compared the two genetically highly divergent wild-type strains N2 and CB4856. Gene expression was analyzed by microarray assays, and proteins were quantified using stable isotope labeling by amino acids in cell culture. Among all transcribed genes, we found 1,532 genes to be differentially transcribed between the two wild types. Of the total 3,238 quantified proteins, 129 proteins were significantly differentially expressed between N2 and CB4856. The differentially expressed proteins were enriched for genes that function in insulin-signaling and stress-response pathways, underlining strong divergence of these pathways in nematodes. The protein abundance of the two wild-type strains correlates more strongly than protein abundance versus transcript abundance within each wild type. Our findings indicate that in C. elegans only a fraction of the changes in protein abundance can be explained by the changes in mRNA abundance. These findings corroborate with the observations made across species.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Perfilação da Expressão Gênica/métodos , Variação Genética , Proteômica/métodos , Animais , Evolução Biológica , Caenorhabditis elegans/classificação , Proteínas de Caenorhabditis elegans/genética , Regulação da Expressão Gênica , Redes Reguladoras de Genes , Marcação por Isótopo/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos
5.
PLoS Genet ; 11(5): e1005236, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25978500

RESUMO

Human cancer is caused by the interplay of mutations in oncogenes and tumor suppressor genes and inherited variations in cancer susceptibility genes. While many of the tumor initiating mutations are well characterized, the effect of genetic background variation on disease onset and progression is less understood. We have used C. elegans genetics to identify genetic modifiers of the oncogenic RAS/MAPK signaling pathway. Quantitative trait locus analysis of two highly diverged C. elegans isolates combined with allele swapping experiments identified the polymorphic monoamine oxidase A (MAOA) gene amx-2 as a negative regulator of RAS/MAPK signaling. We further show that the serotonin metabolite 5-hydroxyindoleacetic acid (5-HIAA), which is a product of MAOA catalysis, systemically inhibits RAS/MAPK signaling in different organs of C. elegans. Thus, MAOA activity sets a global threshold for MAPK activation by controlling 5-HIAA levels. To our knowledge, 5-HIAA is the first endogenous small molecule that acts as a systemic inhibitor of RAS/MAPK signaling.


Assuntos
Regulação da Expressão Gênica , Ácido Hidroxi-Indolacético/química , Sistema de Sinalização das MAP Quinases , Inibidores de Proteínas Quinases/química , Proteínas Proto-Oncogênicas p21(ras)/antagonistas & inibidores , Serotonina/química , Alelos , Animais , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Mapeamento Cromossômico , Técnicas de Genotipagem , Monoaminoxidase/genética , Monoaminoxidase/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Locos de Características Quantitativas , Transdução de Sinais
6.
BMC Genomics ; 17: 280, 2016 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-27066825

RESUMO

BACKGROUND: The invertebrate immune system comprises physiological mechanisms, physical barriers and also behavioral responses. It is generally related to the vertebrate innate immune system and widely believed to provide nonspecific defense against pathogens, whereby the response to different pathogen types is usually mediated by distinct signalling cascades. Recent work suggests that invertebrate immune defense can be more specific at least at the phenotypic level. The underlying genetic mechanisms are as yet poorly understood. RESULTS: We demonstrate in the model invertebrate Caenorhabditis elegans that a single gene, a homolog of the mammalian neuropeptide Y receptor gene, npr-1, mediates contrasting defense phenotypes towards two distinct pathogens, the Gram-positive Bacillus thuringiensis and the Gram-negative Pseudomonas aeruginosa. Our findings are based on combining quantitative trait loci (QTLs) analysis with functional genetic analysis and RNAseq-based transcriptomics. The QTL analysis focused on behavioral immune defense against B. thuringiensis, using recombinant inbred lines (RILs) and introgression lines (ILs). It revealed several defense QTLs, including one on chromosome X comprising the npr-1 gene. The wildtype N2 allele for the latter QTL was associated with reduced defense against B. thuringiensis and thus produced an opposite phenotype to that previously reported for the N2 npr-1 allele against P. aeruginosa. Analysis of npr-1 mutants confirmed these contrasting immune phenotypes for both avoidance behavior and nematode survival. Subsequent transcriptional profiling of C. elegans wildtype and npr-1 mutant suggested that npr-1 mediates defense against both pathogens through p38 MAPK signaling, insulin-like signaling, and C-type lectins. Importantly, increased defense towards P. aeruginosa seems to be additionally influenced through the induction of oxidative stress genes and activation of GATA transcription factors, while the repression of oxidative stress genes combined with activation of Ebox transcription factors appears to enhance susceptibility to B. thuringiensis. CONCLUSIONS: Our findings highlight the role of a single gene, npr-1, in fine-tuning nematode immune defense, showing the ability of the invertebrate immune system to produce highly specialized and potentially opposing immune responses via single regulatory genes.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Imunidade Inata/genética , Locos de Características Quantitativas , Receptores de Neuropeptídeo Y/genética , Animais , Bacillus thuringiensis , Caenorhabditis elegans/imunologia , Caenorhabditis elegans/microbiologia , Pseudomonas aeruginosa , Transdução de Sinais , Transcriptoma
7.
Trends Genet ; 29(6): 367-74, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23428113

RESUMO

Many organisms have stress response pathways, components of which share homology with players in complex human disease pathways. Research on stress response in the nematode worm Caenorhabditis elegans has provided detailed insights into the genetic and molecular mechanisms underlying complex human diseases. In this review we focus on four different types of environmental stress responses - heat shock, oxidative stress, hypoxia, and osmotic stress - and on how these can be used to study the genetics of complex human diseases. All four types of responses involve the genetic machineries that underlie a number of complex human diseases such as cancer and neurodegenerative diseases, including Alzheimer's and Parkinson's. We highlight the types of stress response experiments required to detect the genes and pathways underlying human disease and suggest that studying stress biology in worms can be translated to understanding human disease and provide potential targets for drug discovery.


Assuntos
Caenorhabditis elegans/fisiologia , Estresse Fisiológico , Envelhecimento/fisiologia , Animais , Caenorhabditis elegans/efeitos dos fármacos , Modelos Animais de Doenças , Descoberta de Drogas , Resposta ao Choque Térmico , Humanos , Hipóxia , Estresse Oxidativo , Estresse Fisiológico/efeitos dos fármacos
8.
Mol Ecol ; 25(8): 1759-68, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26615058

RESUMO

Epigenetic variation has been proposed to contribute to the success of asexual plants, either as a contributor to phenotypic plasticity or by enabling transient adaptation via selection on transgenerationally stable, but reversible, epialleles. While recent studies in experimental plant populations have shown the potential for epigenetic mechanisms to contribute to adaptive phenotypes, it remains unknown whether heritable variation in ecologically relevant traits is at least partially epigenetically determined in natural populations. Here, we tested the hypothesis that DNA methylation variation contributes to heritable differences in flowering time within a single widespread apomictic clonal lineage of the common dandelion (Taraxacum officinale s. lat.). Apomictic clone members of the same apomictic lineage collected from different field sites showed heritable differences in flowering time, which was correlated with inherited differences in methylation-sensitive AFLP marker profiles. Differences in flowering between apomictic clone members were significantly reduced after in vivo demethylation using the DNA methyltransferase inhibitor zebularine. This synchronization of flowering times suggests that flowering time divergence within an apomictic lineage was mediated by differences in DNA methylation. While the underlying basis of the methylation polymorphism at functional flowering time-affecting loci remains to be demonstrated, our study shows that epigenetic variation contributes to heritable phenotypic divergence in ecologically relevant traits in natural plant populations. This result also suggests that epigenetic mechanisms can facilitate adaptive divergence within genetically uniform asexual lineages.


Assuntos
Metilação de DNA , Epigênese Genética , Flores/fisiologia , Taraxacum/genética , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , República Tcheca , Finlândia , Genética Populacional , Alemanha , Repetições de Microssatélites , Reprodução Assexuada , Taraxacum/fisiologia
9.
Nucleic Acids Res ; 42(Database issue): D794-801, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24217915

RESUMO

Interactions between proteins are highly conserved across species. As a result, the molecular basis of multiple diseases affecting humans can be studied in model organisms that offer many alternative experimental opportunities. One such organism-Caenorhabditis elegans-has been used to produce much molecular quantitative genetics and systems biology data over the past decade. We present WormQTL(HD) (Human Disease), a database that quantitatively and systematically links expression Quantitative Trait Loci (eQTL) findings in C. elegans to gene-disease associations in man. WormQTL(HD), available online at http://www.wormqtl-hd.org, is a user-friendly set of tools to reveal functionally coherent, evolutionary conserved gene networks. These can be used to predict novel gene-to-gene associations and the functions of genes underlying the disease of interest. We created a new database that links C. elegans eQTL data sets to human diseases (34 337 gene-disease associations from OMIM, DGA, GWAS Central and NHGRI GWAS Catalogue) based on overlapping sets of orthologous genes associated to phenotypes in these two species. We utilized QTL results, high-throughput molecular phenotypes, classical phenotypes and genotype data covering different developmental stages and environments from WormQTL database. All software is available as open source, built on MOLGENIS and xQTL workbench.


Assuntos
Caenorhabditis elegans/genética , Bases de Dados Genéticas , Modelos Animais de Doenças , Doença/genética , Variação Genética , Locos de Características Quantitativas , Animais , Expressão Gênica , Genoma Helmíntico , Genômica , Humanos , Internet , Pressão Osmótica , Fenótipo
10.
Nucleic Acids Res ; 41(Database issue): D738-43, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23180786

RESUMO

Here, we present WormQTL (http://www.wormqtl.org), an easily accessible database enabling search, comparative analysis and meta-analysis of all data on variation in Caenorhabditis spp. Over the past decade, Caenorhabditis elegans has become instrumental for molecular quantitative genetics and the systems biology of natural variation. These efforts have resulted in a valuable amount of phenotypic, high-throughput molecular and genotypic data across different developmental worm stages and environments in hundreds of C. elegans strains. WormQTL provides a workbench of analysis tools for genotype-phenotype linkage and association mapping based on but not limited to R/qtl (http://www.rqtl.org). All data can be uploaded and downloaded using simple delimited text or Excel formats and are accessible via a public web user interface for biologists and R statistic and web service interfaces for bioinformaticians, based on open source MOLGENIS and xQTL workbench software. WormQTL welcomes data submissions from other worm researchers.


Assuntos
Caenorhabditis/genética , Bases de Dados Genéticas , Locos de Características Quantitativas , Animais , Caenorhabditis elegans/genética , Expressão Gênica , Estudos de Associação Genética , Variação Genética , Internet
11.
J Exp Bot ; 65(22): 6603-15, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25240065

RESUMO

Seed performance after dispersal is highly dependent on parental environmental cues, especially during seed formation and maturation. Here we examine which environmental factors are the most dominant in this respect and whether their effects are dependent on the genotypes under investigation. We studied the influence of light intensity, photoperiod, temperature, nitrate, and phosphate during seed development on five plant attributes and thirteen seed attributes, using 12 Arabidopsis genotypes that have been reported to be affected in seed traits. As expected, the various environments during seed development resulted in changed plant and/or seed performances. Comparative analysis clearly indicated that, overall, temperature plays the most dominant role in both plant and seed performance, whereas light has a prominent impact on plant traits. In comparison to temperature and light, nitrate mildly affected some of the plant and seed traits while phosphate had even less influence on those traits. Moreover, clear genotype-by-environment interactions were identified. This was shown by the fact that individual genotypes responded differentially to the environmental conditions. Low temperature significantly increased seed dormancy and decreased seed longevity of NILDOG1 and cyp707a1-1, whereas low light intensity increased seed dormancy and decreased seed longevity of NILDOG3 and NILDOG6. This also indicates that different genetic and molecular pathways are involved in the plant and seed responses. By identifying environmental conditions that affect the dormancy vs longevity correlation in the same way as previously identified naturally occurring loci, we have identified selective forces that probably shaped evolution for these important seed traits.


Assuntos
Arabidopsis/genética , Arabidopsis/fisiologia , Meio Ambiente , Interação Gene-Ambiente , Sementes/genética , Sementes/fisiologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/efeitos da radiação , Flores/efeitos dos fármacos , Flores/fisiologia , Flores/efeitos da radiação , Genótipo , Germinação/efeitos dos fármacos , Germinação/efeitos da radiação , Luz , Manitol/farmacologia , Modelos Biológicos , Dormência de Plantas/efeitos dos fármacos , Dormência de Plantas/efeitos da radiação , Característica Quantitativa Herdável , Reprodução/efeitos dos fármacos , Reprodução/efeitos da radiação , Cloreto de Sódio/farmacologia , Estresse Fisiológico/efeitos dos fármacos , Estresse Fisiológico/efeitos da radiação
12.
BMC Biol ; 11: 93, 2013 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-23957880

RESUMO

BACKGROUND: Analyzing and understanding the relationship between genotypes and phenotypes is at the heart of genetics. Research on the nematode Caenorhabditis elegans has been instrumental for unraveling genotype-phenotype relations, and has important implications for understanding the biology of mammals, but almost all studies, including forward and reverse genetic screens, are limited by investigations in only one canonical genotype. This hampers the detection and functional analysis of allelic variants, which play a key role in controlling many complex traits. It is therefore essential to explore the full potential of the natural genetic variation and evolutionary context of the genotype-phenotype map in wild C. elegans populations. RESULTS: We used multiple wild C. elegans populations freshly isolated from local sites to investigate gene sequence polymorphisms and a multitude of phenotypes including the transcriptome, fitness, and behavioral traits. The genotype, transcriptome, and a number of fitness traits showed a direct link with the original site of the strains. The separation between the isolation sites was prevalent on all chromosomes, but chromosome V was the largest contributor to this variation. These results were supported by a differential food preference of the wild isolates for naturally co-existing bacterial species. Comparing polymorphic genes between the populations with a set of genes extracted from 19 different studies on gene expression in C. elegans exposed to biotic and abiotic factors, such as bacteria, osmotic pressure, and temperature, revealed a significant enrichment for genes involved in gene-environment interactions and protein degradation. CONCLUSIONS: We found that wild C. elegans populations are characterized by gene-environment signatures, and we have unlocked a wealth of genotype-phenotype relations for the first time. Studying natural isolates provides a treasure trove of evidence compared with that unearthed by the current research in C. elegans, which covers only a diminutive part of the myriad of genotype-phenotype relations that are present in the wild.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , DNA de Helmintos/isolamento & purificação , Interação Gene-Ambiente , Genoma Helmíntico , Animais , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , DNA de Helmintos/genética , Evolução Molecular , Genética Populacional , Genótipo , Fenótipo , Polimorfismo Genético , Transcriptoma
13.
Int J Food Microbiol ; 410: 110495, 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-37980813

RESUMO

Aspergilli can be used to produce food but can spoil it as well. Both food production and spoilage are initiated by germination of the conidia of these fungi that have been introduced by inoculation and contamination, respectively. Germination of these spores includes activation, swelling, establishment of cell polarity, and formation of a germ tube. So far, only quantitative single-species germination studies of fungal spores have been performed. Here, spore germination of the food spoilage fungus Aspergillus niger was studied quantitatively in mono-culture or when mixed with other food-relevant aspergilli (Aspergillus nidulans, Aspergillus terreus, Aspergillus clavatus, and Aspergillus oryzae). In the presence of the germination inducing amino acids proline or alanine, but not in the case of the lowly inducing amino acid arginine, the incidence of swelling and germ tube formation was reduced when 35,000 extra conidia of Aspergillus niger were added to wells containing 5000 of these spores. Adding 35,000 spores of one of the other aspergilli also did not have an effect on germination in the presence of arginine, but the germination inhibition was stronger when compared to the extra A. niger spores in the case of alanine. A similar effect was obtained with proline. Together, results show that the germination of A. niger conidia is impacted by the density of its own spores and that of other aspergilli under favorable nutritional conditions. These results increase our understanding of food spoilage by fungi and can be used to optimize food production with fungi.


Assuntos
Alanina , Aspergillus niger , Esporos Fúngicos , Alanina/metabolismo , Prolina/metabolismo , Prolina/farmacologia , Arginina/farmacologia
14.
Genome Res ; 20(7): 929-37, 2010 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-20488933

RESUMO

Gene expression becomes more variable with age, and it is widely assumed that this is due to a decrease in expression regulation. But currently there is no understanding how gene expression regulatory patterns progress with age. Here we explored genome-wide gene expression variation and regulatory loci (eQTL) in a population of developing and aging C. elegans recombinant inbred worms. We found almost 900 genes with an eQTL, of which almost half were found to have a genotype-by-age effect ((gxa)eQTL). The total number of eQTL decreased with age, whereas the variation in expression increased. In developing worms, the number of genes with increased expression variation (1282) was similar to the ones with decreased expression variation (1328). In aging worms, the number of genes with increased variation (1772) was nearly five times higher than the number of genes with a decreased expression variation (373). The number of cis-acting eQTL in juveniles decreased by almost 50% in old worms, whereas the number of trans-acting loci decreased by approximately 27%, indicating that cis-regulation becomes relatively less frequent than trans-regulation in aging worms. Of the 373 genes with decreased expression level variation in aging worms, approximately 39% had an eQTL compared with approximately 14% in developing worms. (gxa)eQTL were found for approximately 21% of these genes in aging worms compared with only approximately 6% in developing worms. We highlight three examples of linkages: in young worms (pgp-6), in old worms (daf-16), and throughout life (lips-16). Our findings demonstrate that eQTL patterns are strongly affected by age, and suggest that gene network integrity declines with age.


Assuntos
Envelhecimento/genética , Caenorhabditis elegans/genética , Regulação da Expressão Gênica , Genoma , Animais , Caenorhabditis elegans/crescimento & desenvolvimento , Proteínas de Caenorhabditis elegans/genética , Mapeamento Cromossômico/métodos , Fatores de Transcrição Forkhead , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Loci Gênicos , Marcadores Genéticos/fisiologia , Variação Genética/fisiologia , Genoma/genética , Genótipo , Locos de Características Quantitativas , Fatores de Transcrição/genética
15.
PLoS Genet ; 5(9): e1000638, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19730687

RESUMO

Natural genetic variation in Arabidopsis thaliana exists for many traits and often reflects acclimation to local environments. Studying natural variation has proven valuable in the characterization of phenotypic traits and, in particular, in identifying genetic factors controlling these traits. It has been previously shown that chromatin compaction changes during development and biotic stress. To gain more insight into the genetic control of chromatin compaction, we investigated the nuclear phenotype of 21 selected Arabidopsis accessions from different geographic origins and habitats. We show natural variation in chromatin compaction and demonstrate a positive correlation with latitude of geographic origin. The level of compaction appeared to be dependent on light intensity. A novel approach, combining Quantitative Trait Locus (QTL) mapping and microscopic examination, pointed at PHYTOCHROME-B (PHYB) and HISTONE DEACETYLASE-6 (HDA6) as positive regulators of light-controlled chromatin compaction. Indeed, mutant analyses demonstrate that both factors affect global chromatin organization. HDA6, in addition, strongly promotes the light-mediated compaction of the Nucleolar Organizing Regions (NORs). The accession Cape Verde Islands-0 (Cvi-0), which shows sequence polymorphism in the PHYB gene and in the HDA6 promotor, resembles the hda6 mutant in having reduced chromatin compaction and decreased methylation levels of DNA and histone H3K9 at the NORs. We provide evidence that chromatin organization is controlled by light intensity. We propose that chromatin plasticity is associated with acclimation of Arabidopsis to its environment. The polymorphic alleles such as PHYB and HDA6 control this process.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Arabidopsis/efeitos da radiação , Cromatina/metabolismo , Histona Desacetilases/metabolismo , Fitocromo B/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Cromatina/genética , Regulação da Expressão Gênica de Plantas/efeitos da radiação , Histona Desacetilases/genética , Luz , Fitocromo B/genética
16.
Plant Physiol ; 154(3): 1067-78, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20833726

RESUMO

Gene expression differences between individuals within a species can be largely explained by differences in genetic background. The effect of genetic variants (alleles) of genes on expression can be studied in a multifactorial way by the application of genetical genomics or expression quantitative trait locus mapping. In this paper, we present a strategy to construct regulatory networks by the application of genetical genomics in combination with transcript profiling of mutants that are disrupted in single genes. We describe the network identification downstream of the receptor-like kinase ERECTA in Arabidopsis (Arabidopsis thaliana). Extending genetical genomics on the Landsberg erecta/Cape Verde Islands (Ler/Cvi) recombinant inbred population with expression profiling of monogenic mutants enabled the identification of regulatory networks in the so far elusive ERECTA signal transduction cascade. We provide evidence that ERECTA is the causal gene for the major hotspot for transcript regulation in the Arabidopsis Ler/Cvi recombinant inbred population. We further propose additional genetic variation between Ler and Cvi in loci of the signaling pathway downstream of ERECTA and suggest candidate genes underlying these loci. Integration of publicly available microarray expression data of other monogenic mutants allowed us to link ERECTA to a downstream mitogen-activated protein kinase signaling cascade. Our study shows that microarray data of monogenic mutants can be effectively used in combination with genetical genomics data to enhance the identification of genetic regulatory networks.


Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Genômica/métodos , Proteínas Serina-Treonina Quinases/metabolismo , Receptores de Superfície Celular/metabolismo , Transdução de Sinais , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , DNA de Plantas/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Redes Reguladoras de Genes , Sistema de Sinalização das MAP Quinases , Mutação , Análise de Sequência com Séries de Oligonucleotídeos , Proteínas Serina-Treonina Quinases/genética , Locos de Características Quantitativas , Receptores de Superfície Celular/genética , Fatores de Transcrição/metabolismo
17.
Nucleic Acids Res ; 37(16): e110, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19542186

RESUMO

Recombinant inbred lines (RILs) derived from Caenorhabditis elegans wild-type N2 and CB4856 are increasingly being used for mapping genes underlying complex traits. To speed up mapping and gene discovery, introgression lines (ILs) offer a powerful tool for more efficient QTL identification. We constructed a library of 90 ILs, each carrying a single homozygous CB4856 genomic segment introgressed into the genetic background of N2. The ILs were genotyped by 123 single-nucleotide polymorphism (SNP) markers. The proportion of the CB4856 segments in most lines does not exceed 3%, and together the introgressions cover 96% of the CB4856 genome. The value of the IL library was demonstrated by identifying novel loci underlying natural variation in two ageing-related traits, i.e. lifespan and pharyngeal pumping rate. Bin mapping of lifespan resulted in six QTLs, which all have a lifespan-shortening effect on the CB4856 allele. We found five QTLs for the decrease in pumping rate, of which four colocated with QTLs found for average lifespan. This suggests pleiotropic or closely linked QTL associated with lifespan and pumping rate. Overall, the presented IL library provides a versatile resource toward easier and efficient fine mapping and functional analyses of loci and genes underlying complex traits in C. elegans.


Assuntos
Caenorhabditis elegans/genética , Biblioteca Genômica , Locos de Características Quantitativas , Animais , Animais Endogâmicos , Caenorhabditis elegans/fisiologia , Mapeamento Cromossômico , Genoma Helmíntico , Longevidade/genética , Faringe/fisiologia
18.
Trends Plant Sci ; 14(4): 214-8, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19303350

RESUMO

The Arabidopsis thaliana accession Landsberg erecta contains an induced mutation in the leucine-rich repeat receptor-like Ser/Thr kinase gene ERECTA. Landsberg erecta is commonly used as a genetic background in mutant screens and in natural variation studies. Therefore, the erecta mutation is present in many loss-of-function mutants and recombinant inbred lines. Information on how the absence of functional ERECTA affects the interpretation of obtained phenotypic results is scattered. In this report we inventoried ERECTA functions and highlight ERECTA as a pleiotropic regulator of developmental and physiological processes, as well as a modulator of responses to environmental stimuli.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/crescimento & desenvolvimento , Proteínas Serina-Treonina Quinases/fisiologia , Receptores de Superfície Celular/fisiologia , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Mutação , Proteínas Serina-Treonina Quinases/genética , Receptores de Superfície Celular/genética
19.
Environ Int ; 154: 106551, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-33857708

RESUMO

Air is a major conduit for the dispersal of organisms at the local and the global scale. Most research has focused on the dispersal of plants, vertebrates and human disease agents. However, the air represents a key dispersal medium also for bacteria, fungi and protists. Many of those represent potential pathogens of animals and plants and have until now gone largely unrecorded. Here we studied the turnover in composition of the entire aerobiome, the collective diversity of airborne microorganisms. For that we performed daily analyses of all prokaryotes and eukaryotes (including plants) using multi-marker high-throughput sequencing for a total of three weeks. We linked the resulting communities to local weather conditions, to assess determinants of aerobiome composition and distribution. We observed hundreds of microbial taxa, mostly belonging to spore-forming organisms including fungi, but also protists. Additionally, we detected many potential human- and plant-pathogens. Community composition fluctuated on a daily basis and was linked to concurrent weather conditions, particularly air pressure and temperature. Using network analyses, we identified taxonomically diverse groups of organisms with correlated temporal dynamics. In part, this was due to co-variation with environmental conditions, while we could also detect specific host-parasite interactions. This study provides the first full inventory of the aerobiome and identifies putative drivers of its dynamics in terms of taxon composition. This knowledge can help develop early warning systems against pathogens and improve our understanding of microbial dispersal.


Assuntos
Microbiota , Alérgenos , Bactérias/genética , Fungos/genética , Humanos , Microbiota/genética , Plantas
20.
Front Microbiol ; 10: 505, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30936858

RESUMO

Introduced exotic plant species that originate from other continents are known to alter soil microbial community composition and nutrient cycling. Plant species that expand range to higher latitudes and altitudes as a consequence of current climate warming might as well affect the composition and functioning of native soil communities in their new range. However, the functional consequences of plant origin have been poorly studied in the case of plant range shifts. Here, we determined rhizosphere bacterial communities of four intracontinental range-expanding plant species in comparison with their four congeneric natives grown in soils collected from underneath those plant species in the field and in soils that are novel to them. We show that, when controlling for both species relatedness and soil characteristics, range-expanding plant species in higher latitude ecosystems will influence soil bacterial community composition and nutrient cycling in a manner similar to congeneric related native species. Our results highlight the importance to include phylogenetically controlled comparisons to disentangle the effect of origin from the effect of contrasting plant traits in the context of exotic plant species.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA