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1.
Science ; 366(6465): 594-599, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31672890

RESUMO

We used 20 de novo genome assemblies to probe the speciation history and architecture of gene flow in rapidly radiating Heliconius butterflies. Our tests to distinguish incomplete lineage sorting from introgression indicate that gene flow has obscured several ancient phylogenetic relationships in this group over large swathes of the genome. Introgressed loci are underrepresented in low-recombination and gene-rich regions, consistent with the purging of foreign alleles more tightly linked to incompatibility loci. Here, we identify a hitherto unknown inversion that traps a color pattern switch locus. We infer that this inversion was transferred between lineages by introgression and is convergent with a similar rearrangement in another part of the genus. These multiple de novo genome sequences enable improved understanding of the importance of introgression and selective processes in adaptive radiation.

2.
Artigo em Inglês | MEDLINE | ID: mdl-31712408

RESUMO

Color pattern mimicry in Heliconius butterflies is a classic case study of complex trait adaptation via selection on a few large effect genes. Association studies have linked color pattern variation to a handful of noncoding regions, yet the presumptive cis-regulatory elements (CREs) that control color patterning remain unknown. Here we combine chromatin assays, DNA sequence associations, and genome editing to functionally characterize 5 cis-regulatory elements of the color pattern gene optix We were surprised to find that the cis-regulatory architecture of optix is characterized by pleiotropy and regulatory fragility, where deletion of individual cis-regulatory elements has broad effects on both color pattern and wing vein development. Remarkably, we found orthologous cis-regulatory elements associate with wing pattern convergence of distantly related comimics, suggesting that parallel coevolution of ancestral elements facilitated pattern mimicry. Our results support a model of color pattern evolution in Heliconius where changes to ancient, multifunctional cis-regulatory elements underlie adaptive radiation.

3.
Genome Biol Evol ; 11(10): 2963-2975, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31518398

RESUMO

Butterfly eyes are complex organs that are composed of a diversity of proteins and they play a central role in visual signaling and ultimately, speciation, and adaptation. Here, we utilized the whole eye transcriptome to obtain a more holistic view of the evolution of the butterfly eye while accounting for speciation events that co-occur with ancient hybridization. We sequenced and assembled transcriptomes from adult female eyes of eight species representing all major clades of the Heliconius genus and an additional outgroup species, Dryas iulia. We identified 4,042 orthologous genes shared across all transcriptome data sets and constructed a transcriptome-wide phylogeny, which revealed topological discordance with the mitochondrial phylogenetic tree in the Heliconius pupal mating clade. We then estimated introgression among lineages using additional genome data and found evidence for ancient hybridization leading to the common ancestor of Heliconius hortense and Heliconius clysonymus. We estimated the Ka/Ks ratio for each orthologous cluster and performed further tests to demonstrate genes showing evidence of adaptive protein evolution. Furthermore, we characterized patterns of expression for a subset of these positively selected orthologs using qRT-PCR. Taken together, we identified candidate eye genes that show signatures of adaptive molecular evolution and provide evidence of their expression divergence between species, tissues, and sexes. Our results demonstrate: 1) greater evolutionary changes in younger Heliconius lineages, that is, more positively selected genes in the cydno-melpomene-hecale group as opposed to the sara-hortense-erato group, and 2) suggest an ancient hybridization leading to speciation among Heliconius pupal-mating species.

5.
Ann Rheum Dis ; 78(10): 1405-1411, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31278138

RESUMO

OBJECTIVES: To describe the clinical characteristics, treatment response and genetic findings in a large cohort of patients with undefined systemic autoinflammatory diseases (SAIDs). METHODS: Clinical and genetic data from patients with undefined SAIDs were extracted from the Eurofever registry, an international web-based registry that retrospectively collects clinical information on patients with autoinflammatory diseases. RESULTS: This study included 187 patients. Seven patients had a chronic disease course, 180 patients had a recurrent disease course. The median age at disease onset was 4.3 years. Patients had a median of 12 episodes per year, with a median duration of 4 days. Most commonly reported symptoms were arthralgia (n=113), myalgia (n=86), abdominal pain (n=89), fatigue (n=111), malaise (n=104) and mucocutaneous manifestations (n=128). In 24 patients, relatives were affected as well. In 15 patients, genetic variants were found in autoinflammatory genes. Patients with genetic variants more often had affected relatives compared with patients without genetic variants (p=0.005). Most patients responded well to non-steroidal anti-inflammatory drugs (NSAIDs), corticosteroids, colchicine and anakinra. Complete remission was rarely achieved with NSAIDs alone. Notable patterns were found in patients with distinctive symptoms. Patients with pericarditis (n=11) were older at disease onset (33.8 years) and had fewer episodes per year (3.0/year) compared with other patients. Patients with an intellectual impairment (n=8) were younger at disease onset (2.2 years) and often had relatives affected (28.6%). CONCLUSION: This study describes the clinical characteristics of a large cohort of patients with undefined SAIDs. Among these, patients with pericarditis and intellectual impairment appear to comprise distinct subsets.

6.
Artigo em Inglês | MEDLINE | ID: mdl-31325311

RESUMO

OBJECTIVES: The number of innate immune system disorders classified as systemic autoinflammatory diseases (SAID) has increased in recent years. More than 70% of patients with clinical manifestations of SAID did not receive a molecular diagnosis, thus being classed as so-called undifferentiated or undefined SAID (uSAID). The aim of the present study was to evaluate a next-generation sequencing (NGS)-based clinically oriented protocol in patients with uSAID. METHODS: We designed a NGS panel that included 41 genes clustered in seven subpanels. Patients with uSAID were classified into different groups according to their clinical features and sequenced for the coding portions of the 41 genes. RESULTS: Fifty patients were enrolled in the study. Thirty-four patients (72%) displayed recurrent fevers not consistent with a PFAPA phenotype. Sixteen patients displayed a chronic inflammatory disease course. A total of 100 gene variants were found (mean 2 per patient; range 0-6), a quarter of which affected suspected genes. Mutations with a definitive diagnostic impact were detected in two patients. Patients with genetically negative recurrent fevers displayed a prevalent gastrointestinal, skin and articular involvement. Patients responded to steroids on demands (94%) and colchicine, with a response rate of 78%. CONCLUSION: Even with a low molecular diagnostic rate, a NGS-based approach is able to provide a final diagnosis in a proportion of uSAID patients with evident cost-effectiveness. It also allows the identification of a subgroup of genetically negative patients with recurrent fever responding to steroid on demand and colchicine.

8.
PeerJ ; 6: e5502, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30310733

RESUMO

Background: Insects are the most diverse group of animals which have established intricate evolutionary interactions with bacteria. However, the importance of these interactions is still poorly understood. Few studies have focused on a closely related group of insect species, to test the similarities and differences between their microbiota. Heliconius butterflies are a charismatic recent insect radiation that evolved the unique ability to use pollen as a protein source, which affected life history traits and resulted in an elevated speciation rates. We hypothesize that different Heliconius butterflies sharing a similar trophic pollen niche, harbor a similar gut flora within species, population and sexes. Methods: To test our hypothesis, we characterized the microbiota of 38 adult male and female butterflies representing six species of Heliconius butterflies and 2 populations of the same species. We sequenced the V4 region of the 16S rRNA gene with the Roche 454 system and analyzed the data with standard tools for microbiome analysis. Results: Overall, we found a low microbial diversity with only 10 OTUs dominating across all individuals, mostly Proteobacteria and Firmicutes, which accounted for  99.5% of the bacterial reads. When rare reads were considered, we identified a total of 406 OTUs across our samples. We identified reads within Phyla Chlamydiae, found in 5 butterflies of four species. Interestingly, only three OTUs were shared among all 38 individuals (Bacillus, Enterococcus and Enterobacteriaceae). Altogether, the high individual variation overshadowed species and sex differences. Thus, bacterial communities were not structured randomly with 13% of beta-diversity explained by species, and 40 rare OTUs being significantly different across species. Finally, 13 OTUs, including the intercellular symbiont Spiroplasma, varied significantly in relative abundance between males and females. Discussion: The Heliconius microbial communities in these 38 individuals show a low diversity with few differences in the rare microbes between females, males, species or populations. Indeed, Heliconius butterflies, similarly to other insects, are dominated by few OTUs, mainly from Proteobacteria and Firmicutes. The overall low microbial diversity observed contrasts with the high intra-species variation in microbiome composition. This could indicate that much of the microbiome maybe acquired from their surroundings. The significant differences between species and sexes were restricted to rare taxa, which could be important for microbial community stability under changing conditions as seen in other host-microbiome systems. The presence of symbionts like Spiroplasma or Chlamydiae, identified in this study for the first time in Heliconius, could play a vital role in their behavior and evolution by vertical transmission. Altogether, our study represents a step forward into the description of the microbial diversity in a charismatic group of closely related butterflies.

9.
Rheum Dis Clin North Am ; 44(4): 585-603, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30274625

RESUMO

Secondary, AA, amyloidosis is a rare systemic complication that can develop in any long-term inflammatory disorder, and is characterized by the extracellular deposition of fibrils derived from serum amyloid A (SAA) protein. SAA is an acute-phase reactant synthetized largely by hepatocytes under the transcriptional regulation of proinflammatory cytokines. The kidney is the major involved organ with proteinuria as first clinical manifestation; renal biopsy is the commonest diagnostic investigation. Targeted anti-inflammatory treatment promotes normalization of circulating SAA levels preventing amyloid deposition and renal damage. Novel therapies aimed at promoting clearance of existing amyloid deposits soon may be an effective treatment approach.

10.
Methods Ecol Evol ; 9(2): 390-398, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29755717

RESUMO

The use of image data to quantify, study and compare variation in the colors and patterns of organisms requires the alignment of images to establish homology, followed by color-based segmentation of images. Here we describe an R package for image alignment and segmentation that has applications to quantify color patterns in a wide range of organisms. patternize is an R package that quantifies variation in color patterns obtained from image data. patternize first defines homology between pattern positions across specimens either through manually placed homologous landmarks or automated image registration. Pattern identification is performed by categorizing the distribution of colors using an RGB threshold, k-means clustering or watershed transformation.We demonstrate that patternize can be used for quantification of the color patterns in a variety of organisms by analyzing image data for butterflies, guppies, spiders and salamanders. Image data can be compared between sets of specimens, visualized as heatmaps and analyzed using principal component analysis (PCA). patternize has potential applications for fine scale quantification of color pattern phenotypes in population comparisons, genetic association studies and investigating the basis of color pattern variation across a wide range of organisms.

11.
Mol Ecol ; 27(19): 3852-3872, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29569384

RESUMO

Sex chromosomes are disproportionately involved in reproductive isolation and adaptation. In support of such a "large-X" effect, genome scans between recently diverged populations and species pairs often identify distinct patterns of divergence on the sex chromosome compared to autosomes. When measures of divergence between populations are higher on the sex chromosome compared to autosomes, such patterns could be interpreted as evidence for faster divergence on the sex chromosome, that is "faster-X", barriers to gene flow on the sex chromosome. However, demographic changes can strongly skew divergence estimates and are not always taken into consideration. We used 224 whole-genome sequences representing 36 populations from two Heliconius butterfly clades (H. erato and H. melpomene) to explore patterns of Z chromosome divergence. We show that increased divergence compared to equilibrium expectations can in many cases be explained by demographic change. Among Heliconius erato populations, for instance, population size increase in the ancestral population can explain increased absolute divergence measures on the Z chromosome compared to the autosomes, as a result of increased ancestral Z chromosome genetic diversity. Nonetheless, we do identify increased divergence on the Z chromosome relative to the autosomes in parapatric or sympatric species comparisons that imply postzygotic reproductive barriers. Using simulations, we show that this is consistent with reduced gene flow on the Z chromosome, perhaps due to greater accumulation of incompatibilities. Our work demonstrates the importance of taking demography into account to interpret patterns of divergence on the Z chromosome, but nonetheless provides evidence to support the Z chromosome as a strong barrier to gene flow in incipient Heliconius butterfly species.

12.
Orphanet J Rare Dis ; 12(1): 167, 2017 10 18.
Artigo em Inglês | MEDLINE | ID: mdl-29047407

RESUMO

BACKGROUND: Hereditary recurrent fevers (HRF) are a group of rare monogenic diseases leading to recurrent inflammatory flares. A large number of variants has been described for the four genes associated with the best known HRF, namely MEFV, NLRP3, MVK, TNFRSF1A. The Infevers database ( http://fmf.igh.cnrs.fr/ISSAID/infevers ) is a large international registry collecting variants reported in these genes. However, no genotype-phenotype associations are provided, but only the clinical phenotype of the first patient(s) described for each mutation. The aim of this study is to develop a registry of genotype-phenotype associations observed in patients with HRF, enrolled and validated in the Eurofever registry. RESULTS: Genotype-phenotype associations observed in all the patients with HRF enrolled in the Eurofever registry were retrospectively analyzed. For autosomal dominant diseases (CAPS and TRAPS), all mutations were individually analyzed. For autosomal recessive diseases (FMF and MKD), homozygous and heterozygous combinations were described. Mean age of onset, disease course (recurrent or chronic), mean duration of fever episodes, clinical manifestations associated with fever episodes, atypical manifestations, complications and response to treatment were also studied. Data observed in 751 patients (346 FMF, 133 CAPS, 114 MKD, 158 TRAPS) included in the Eurofever registry and validated by experts were summarized in Tables. A total of 149 variants were described: 46 TNFRSF1A and 27 NLRP3 variants, as well as various combinations of 48 MVK and 28 MEFV variants were available. CONCLUSIONS: We provide a potentially useful tool for physicians dealing with HRF, namely a registry of genotype-phenotype associations for patients enrolled in the Eurofever registry. This tool is complementary to the Infevers database and will be available at the Eurofever and Infevers websites.


Assuntos
Estudos de Associação Genética , Doenças Hereditárias Autoinflamatórias/epidemiologia , Doenças Hereditárias Autoinflamatórias/genética , Sistema de Registros , Bases de Dados Genéticas , Europa (Continente)/epidemiologia , Humanos , Estudos Retrospectivos
13.
Nat Ecol Evol ; 1(3): 52, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28523290

RESUMO

Identifying the genomic changes that control morphological variation and understanding how they generate diversity is a major goal of evolutionary biology. In Heliconius butterflies, a small number of genes control the development of diverse wing color patterns. Here, we used full genome sequencing of individuals across the Heliconius erato radiation and closely related species to characterize genomic variation associated with wing pattern diversity. We show that variation around color pattern genes is highly modular, with narrow genomic intervals associated with specific differences in color and pattern. This modular architecture explains the diversity of color patterns and provides a flexible mechanism for rapid morphological diversification.

14.
Clin Exp Rheumatol ; 35(3): 516-517, 2017 May-Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28339360

RESUMO

OBJECTIVES: In 1966, Goldbloom et al. described two children who developed a peculiar clinical picture characterized by intermittent daily bone pain in the lower limbs, fever spikes, increased acute phase reactants and dysproteinaemia. The syndrome occurred two weeks after a group A ß-haemolytic streptococcus infection. So far, only a few cases have been reported in the medical literature in English. METHODS: We report two further cases of Goldbloom's syndrome with a review of the literature in English. RESULTS: Our two patients lived in the same Italian region and presented their syndrome onset a week apart. Early use of STIR MRI revealed an atypical metaphyseal hyperintensity in the femurs and tibias. X-ray showed periosteal hyperostosis. A short cycle of corticosteroids led to rapid recovery of symptoms and disappearance of bone changes. CONCLUSIONS: The reported cases highlight a likely under-recognised post-streptococcal inflammatory periosteal reaction and emphasise the diagnostic utility of the newer imaging modalities.


Assuntos
Fêmur/diagnóstico por imagem , Hipergamaglobulinemia/sangue , Hipoalbuminemia/sangue , Imagem por Ressonância Magnética , Periostite/diagnóstico por imagem , Infecções Estreptocócicas/complicações , Tíbia/diagnóstico por imagem , Corticosteroides/uso terapêutico , Biomarcadores/sangue , Criança , Diagnóstico Precoce , Feminino , Fêmur/microbiologia , Humanos , Hipergamaglobulinemia/diagnóstico , Hipergamaglobulinemia/tratamento farmacológico , Hipergamaglobulinemia/microbiologia , Hipoalbuminemia/diagnóstico , Hipoalbuminemia/tratamento farmacológico , Hipoalbuminemia/microbiologia , Periostite/tratamento farmacológico , Periostite/microbiologia , Valor Preditivo dos Testes , Prednisona/uso terapêutico , Infecções Estreptocócicas/diagnóstico , Infecções Estreptocócicas/microbiologia , Síndrome , Tíbia/microbiologia , Resultado do Tratamento
15.
Mol Cytogenet ; 9: 78, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27766118

RESUMO

BACKGROUND: Deletions of the long arm of chromosome 18 cause a common autosomal syndrome clinically characterized by a protean clinical phenotype. CASE PRESENTATION: We report on a 16-month-old male infant affected by fever attacks apparently unrelated with any infectious or inflammatory symptoms, growth retardation, bilateral vertical talus, congenital aural atresia, dysmorphisms, mild psychomotor delay, and peculiar neuroradiological features. Array-CGH analysis revealed one of the smallest 18q22.3q23 interstitial deletions involving five genes: TSHZ1, ZNF516, ZNF236, MBP, and GALR1. CONCLUSIONS: Herein we focus on previously unreported heralding symptoms and neuroradiological abnormalities which enlarge the spectrum of 18q deletion syndrome demonstrating that a small deletion can determine a complex phenotype.

16.
Clin Exp Rheumatol ; 34(3): 527-30, 2016 May-Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27268780

RESUMO

OBJECTIVES: Eosinophilic fasciitis is an uncommon scleroderma-like disorder characterised by induration and thickening of skin and soft tissue, usually associated with peripheral eosinophilia, poorly characterised in childhood. METHODS: We report 3 paediatric cases of eosinophilic fasciitis showing unusual clinical and histopathological features with a review of the literature. RESULTS: All cases presented progressive motility impairment started from upper limbs with no skin abnormalities. All cases showed systemic inflammatory involvement and 2 patients had acute complications. Two patients developed disabling outcomes despite appropriate treatments. CONCLUSIONS: Eosinophilic fasciitis may present unusual clinical and histopathological features during childhood and requires early recognition in order to prevent acute complications and disabling outcomes.


Assuntos
Contratura , Eosinofilia , Fáscia/patologia , Fasciite , Glucocorticoides/administração & dosagem , Metotrexato/administração & dosagem , Modalidades de Fisioterapia , Antirreumáticos/administração & dosagem , Pré-Escolar , Contratura/diagnóstico , Contratura/etiologia , Contratura/prevenção & controle , Diagnóstico Diferencial , Diagnóstico Precoce , Eosinofilia/sangue , Eosinofilia/complicações , Eosinofilia/diagnóstico , Eosinofilia/fisiopatologia , Eosinofilia/terapia , Fasciite/sangue , Fasciite/complicações , Fasciite/diagnóstico , Fasciite/fisiopatologia , Fasciite/terapia , Feminino , Humanos , Imagem por Ressonância Magnética/métodos , Resultado do Tratamento
17.
BMC Genomics ; 17: 254, 2016 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-27004525

RESUMO

BACKGROUND: In a world of chemical cues, smell and taste are essential senses for survival. Here we focused on Heliconius, a diverse group of butterflies that exhibit variation in pre- and post-zygotic isolation and chemically-mediated behaviors across their phylogeny. Our study examined the ionotropic receptors, a recently discovered class of receptors that are some of the most ancient chemical receptors. RESULTS: We found more ionotropic receptors in Heliconius (31) than in Bombyx mori (25) or in Danaus plexippus (27). Sixteen genes in Lepidoptera were not present in Diptera. Only IR7d4 was exclusively found in butterflies and two expansions of IR60a were exclusive to Heliconius. A genome-wide comparison between 11 Heliconius species revealed instances of pseudogenization, gene gain, and signatures of positive selection across the phylogeny. IR60a2b and IR60a2d are unique to the H. melpomene, H. cydno, and H. timareta clade, a group where chemosensing is likely involved in pre-zygotic isolation. IR60a2b also displayed copy number variations (CNVs) in distinct populations of H. melpomene and was the only gene significantly higher expressed in legs and mouthparts than in antennae, which suggests a gustatory function. dN/dS analysis suggests more frequent positive selection in some intronless IR genes and in particular in the sara/sapho and melpomene/cydno/timareta clades. IR60a1 was the only gene with an elevated dN/dS along a major phylogenetic branch associated with pupal mating. Only IR93a was differentially expressed between sexes. CONCLUSIONS: All together these data make Heliconius butterflies one of the very few insects outside Drosophila where IRs have been characterized in detail. Our work outlines a dynamic pattern of IR gene evolution throughout the Heliconius radiation which could be the result of selective pressure to find potential mates or host-plants.


Assuntos
Evolução Biológica , Borboletas/genética , Genes de Insetos , Receptores Ionotrópicos de Glutamato/genética , Animais , Borboletas/classificação , Variações do Número de Cópias de DNA , Feminino , Masculino , Filogenia , Seleção Genética
18.
Pediatr Neurol ; 55: 58-63, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26718981

RESUMO

BACKGROUND: Female carriers of Duchenne muscular dystrophy (DMD), although usually asymptomatic, develop muscle weakness up to 17% of the time, and a third present cardiac abnormalities or cognitive impairment. Clinical features of DMD carriers during childhood are poorly known. PATIENTS: We describe a cohort of pediatric DMD carriers, providing clinical, genetic, and histopathologic features, with a mean follow-up of 7 years. RESULTS: Fifteen females with a DMD mutation (age range 5 to 18 years) were included. Seven patients (46%) presented with clinically evident symptoms and signs such as limb girdle weakness, abnormal gait, and exercise intolerance. The other eight patients (53%) were evaluated because of an incidental finding of elevated level of creatine kinase. Creatine kinase level was elevated in all, ranging from 392 to 13,000 U/L. Calf hypertrophy was observed in eight patients (53%). No patient developed respiratory or cardiac involvement. The most frequent complication was scoliosis (46%). Four patients (29%) also presented minor learning disabilities or behavioral problems. We performed electromyography in half of patients, showing myopathic pattern in four (53%). Muscle biopsy revealed a mosaic reduction of dystrophin in nine available cases. DMD gene mutations were mostly deletions (71%), resulting in loss of reading frame in five patients (36%). The three patients who experienced the most severe disease course were affected either by a nonsense or frameshift mutation. CONCLUSIONS: Our analysis suggests that DMD gene mutations may be suspected in a female child with persistently elevated levels of creatine kinase. Evidence of scoliosis, calf hypertrophy, or myopathic pattern at electromyography may also be helpful, and muscle biopsy is always indicative. DMD carriers should be followed for subtle orthopedic and psychiatric complications during childhood.


Assuntos
Creatina Quinase/sangue , Distrofina/genética , Distrofia Muscular de Duchenne , Adolescente , Criança , Pré-Escolar , Eletromiografia , Feminino , Seguimentos , Mutação da Fase de Leitura , Humanos , Distrofia Muscular de Duchenne/sangue , Distrofia Muscular de Duchenne/genética , Distrofia Muscular de Duchenne/patologia , Distrofia Muscular de Duchenne/fisiopatologia , Deleção de Sequência
19.
BMC Evol Biol ; 15: 204, 2015 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-26403600

RESUMO

BACKGROUND: A key to understanding the origins of species is determining the evolutionary processes that drive the patterns of genomic divergence during speciation. New genomic technologies enable the study of high-resolution genomic patterns of divergence across natural speciation continua, where taxa pairs with different levels of reproductive isolation can be used as proxies for different stages of speciation. Empirical studies of these speciation continua can provide valuable insights into how genomes diverge during speciation. METHODS: We examine variation across a handful of genomic regions in parapatric and allopatric populations of Heliconius butterflies with varying levels of reproductive isolation. Genome sequences were mapped to 2.2-Mb of the H. erato genome, including 1-Mb across the red color pattern locus and multiple regions unlinked to color pattern variation. RESULTS: Phylogenetic analyses reveal a speciation continuum of pairs of hybridizing races and incipient species in the Heliconius erato clade. Comparisons of hybridizing pairs of divergently colored races and incipient species reveal that genomic divergence increases with ecological and reproductive isolation, not only across the locus responsible for adaptive variation in red wing coloration, but also at genomic regions unlinked to color pattern. DISCUSSION: We observe high levels of divergence between the incipient species H. erato and H. himera, suggesting that divergence may accumulate early in the speciation process. Comparisons of genomic divergence between the incipient species and allopatric races suggest that limited gene flow cannot account for the observed high levels of divergence between the incipient species. CONCLUSIONS: Our results provide a reconstruction of the speciation continuum across the H. erato clade and provide insights into the processes that drive genomic divergence during speciation, establishing the H. erato clade as a powerful framework for the study of speciation.


Assuntos
Borboletas/anatomia & histologia , Borboletas/genética , Fluxo Gênico , Genes de Insetos , Pigmentação , Asas de Animais/anatomia & histologia , Animais , Evolução Biológica , Borboletas/classificação , Especiação Genética , Hibridização Genética , Filogenia
20.
Genetics ; 200(1): 1-19, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25953905

RESUMO

Wing-pattern mimicry in butterflies has provided an important example of adaptation since Charles Darwin and Alfred Russell Wallace proposed evolution by natural selection >150 years ago. The neotropical butterfly genus Heliconius played a central role in the development of mimicry theory and has since been studied extensively in the context of ecology and population biology, behavior, and mimicry genetics. Heliconius species are notable for their diverse color patterns, and previous crossing experiments revealed that much of this variation is controlled by a small number of large-effect, Mendelian switch loci. Recent comparative analyses have shown that the same switch loci control wing-pattern diversity throughout the genus, and a number of these have now been positionally cloned. Using a combination of comparative genetic mapping, association tests, and gene expression analyses, variation in red wing patterning throughout Heliconius has been traced back to the action of the transcription factor optix. Similarly, the signaling ligand WntA has been shown to control variation in melanin patterning across Heliconius and other butterflies. Our understanding of the molecular basis of Heliconius mimicry is now providing important insights into a variety of additional evolutionary phenomena, including the origin of supergenes, the interplay between constraint and evolvability, the genetic basis of convergence, the potential for introgression to facilitate adaptation, the mechanisms of hybrid speciation in animals, and the process of ecological speciation.


Assuntos
Mimetismo Biológico/genética , Borboletas/genética , Evolução Molecular , Pigmentação/genética , Asas de Animais/anatomia & histologia , Animais
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