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The population genetics of mimetic diversity in Heliconius butterflies

Kronforst, Marcus R; Gilbert, Lawrence E
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
EN
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47.53%
Theory predicts strong stabilizing selection on warning patterns within species and convergent evolution among species in Müllerian mimicry systems yet Heliconius butterflies exhibit extreme wing pattern diversity. One potential explanation for the evolution of this diversity is that genetic drift occasionally allows novel warning patterns to reach the frequency threshold at which they gain protection. This idea is controversial, however, because Heliconius butterflies are unlikely to experience pronounced population subdivision and local genetic drift. To examine the fine-scale population genetic structure of Heliconius butterflies we genotyped 316 individuals from eight Costa Rican Heliconius species with 1428 AFLP markers. Six species exhibited evidence of population subdivision and/or isolation by distance indicating genetic differentiation among populations. Across species, variation in the extent of local genetic drift correlated with the roles different species have played in generating pattern diversity: species that originally generated the diversity of warning patterns exhibited striking population subdivision while species that later radiated onto these patterns had intermediate levels of genetic diversity and less genetic differentiation among populations. These data reveal that Heliconius butterflies possess the coarse population genetic structure necessary for local populations to experience pronounced genetic drift which...

Hybrid trait speciation and Heliconius butterflies

Jiggins, Chris D; Salazar, Camilo; Linares, Mauricio; Mavarez, Jesus
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
47.22%
Homoploid hybrid speciation (HHS) is the establishment of a novel species through introgressive hybridization without a change in chromosome number. We discuss different routes by which this might occur and propose a novel term, ‘hybrid trait speciation’, which combines the idea that hybridization can generate adaptive novelty with the ‘magic trait’ model of ecological speciation. Heliconius butterflies contain many putative examples of hybrid colour patterns, but only recently has the HHS hypothesis been tested explicitly in this group. Molecular data has shown evidence for gene flow between many distinct species. Furthermore, the colour pattern of Heliconius heurippa can be recreated in laboratory crosses between Heliconius melpomene and Heliconius cydno and, crucially, plays a role in assortative mating between the three species. Nonetheless, although the genome of H. heurippa shows evidence for hybridization, it is not a mosaic of the two parental species. Instead, ongoing hybridization has likely blurred any signal of the original speciation event. We argue that where hybridization leads to novel adaptive traits that also cause reproductive isolation, it is likely to trigger speciation.

Genetic Evidence for Hybrid Trait Speciation in Heliconius Butterflies

Salazar, Camilo; Baxter, Simon W.; Pardo-Diaz, Carolina; Wu, Grace; Surridge, Alison; Linares, Mauricio; Bermingham, Eldredge; Jiggins, Chris D.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
47.22%
Homoploid hybrid speciation is the formation of a new hybrid species without change in chromosome number. So far, there has been a lack of direct molecular evidence for hybridization generating novel traits directly involved in animal speciation. Heliconius butterflies exhibit bright aposematic color patterns that also act as cues in assortative mating. Heliconius heurippa has been proposed as a hybrid species, and its color pattern can be recreated by introgression of the H. m. melpomene red band into the genetic background of the yellow banded H. cydno cordula. This hybrid color pattern is also involved in mate choice and leads to reproductive isolation between H. heurippa and its close relatives. Here, we provide molecular evidence for adaptive introgression by sequencing genes across the Heliconius red band locus and comparing them to unlinked wing patterning genes in H. melpomene, H. cydno, and H. heurippa. 670 SNPs distributed among 29 unlinked coding genes (25,847bp) showed H. heurippa was related to H. c. cordula or the three species were intermixed. In contrast, among 344 SNPs distributed among 13 genes in the red band region (18,629bp), most showed H. heurippa related with H. c. cordula, but a block of around 6,5kb located in the 3′ of a putative kinesin gene grouped H. heurippa with H. m. melpomene...

Genomic islands of divergence in hybridizing Heliconius butterflies identified by large-scale targeted sequencing

Nadeau, Nicola J.; Whibley, Annabel; Jones, Robert T.; Davey, John W.; Dasmahapatra, Kanchon K.; Baxter, Simon W.; Quail, Michael A.; Joron, Mathieu; ffrench-Constant, Richard H.; Blaxter, Mark L.; Mallet, James; Jiggins, Chris D.
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
Publicado em 05/02/2012 EN
Relevância na Pesquisa
47.22%
Heliconius butterflies represent a recent radiation of species, in which wing pattern divergence has been implicated in speciation. Several loci that control wing pattern phenotypes have been mapped and two were identified through sequencing. These same gene regions play a role in adaptation across the whole Heliconius radiation. Previous studies of population genetic patterns at these regions have sequenced small amplicons. Here, we use targeted next-generation sequence capture to survey patterns of divergence across these entire regions in divergent geographical races and species of Heliconius. This technique was successful both within and between species for obtaining high coverage of almost all coding regions and sufficient coverage of non-coding regions to perform population genetic analyses. We find major peaks of elevated population differentiation between races across hybrid zones, which indicate regions under strong divergent selection. These ‘islands’ of divergence appear to be more extensive between closely related species, but there is less clear evidence for such islands between more distantly related species at two further points along the ‘speciation continuum’. We also sequence fosmid clones across these regions in different Heliconius melpomene races. We find no major structural rearrangements but many relatively large (greater than 1 kb) insertion/deletion events (including gain/loss of transposable elements) that are variable between races.

Introgression of wing pattern alleles and speciation via homoploid hybridization in Heliconius butterflies: a review of evidence from the genome

Brower, Andrew V. Z.
Fonte: The Royal Society Publicador: The Royal Society
Tipo: Artigo de Revista Científica
Publicado em 07/02/2013 EN
Relevância na Pesquisa
47.29%
The diverse Müllerian mimetic wing patterns of neotropical Heliconius (Nymphalidae) have been proposed to be not only aposematic signals to potential predators, but also intra- and interspecific recognition signals that allow the butterflies to maintain their specific identities, and which perhaps drive the process of speciation, as well. Adaptive features under differential selection that also serve as cues for assortative mating have been referred to as ‘magic traits’, which can drive ecological speciation. Such traits are expected to exhibit allelic differentiation between closely related species with ongoing gene flow, whereas unlinked neutral traits are expected to be homogenized to a greater degree by introgression. However, recent evidence suggests that interspecific hybridization among Heliconius butterflies may have resulted in adaptive introgression of these very same traits across species boundaries, and in the evolution of new species by homoploid hybrid speciation. The theory and data supporting various aspects of the apparent paradox of ‘magic trait’ introgression are reviewed, with emphasis on population genomic comparisons of Heliconius melpomene and its close relatives.

Genomic architecture of adaptive color pattern divergence and convergence in Heliconius butterflies

Supple, Megan A.; Hines, Heather M.; Dasmahapatra, Kanchon K.; Lewis, James J.; Nielsen, Dahlia M.; Lavoie, Christine; Ray, David A.; Salazar, Camilo; McMillan, W. Owen; Counterman, Brian A.
Fonte: Cold Spring Harbor Laboratory Press Publicador: Cold Spring Harbor Laboratory Press
Tipo: Artigo de Revista Científica
Publicado em /08/2013 EN
Relevância na Pesquisa
47.3%
Identifying the genetic changes driving adaptive variation in natural populations is key to understanding the origins of biodiversity. The mosaic of mimetic wing patterns in Heliconius butterflies makes an excellent system for exploring adaptive variation using next-generation sequencing. In this study, we use a combination of techniques to annotate the genomic interval modulating red color pattern variation, identify a narrow region responsible for adaptive divergence and convergence in Heliconius wing color patterns, and explore the evolutionary history of these adaptive alleles. We use whole genome resequencing from four hybrid zones between divergent color pattern races of Heliconius erato and two hybrid zones of the co-mimic Heliconius melpomene to examine genetic variation across 2.2 Mb of a partial reference sequence. In the intergenic region near optix, the gene previously shown to be responsible for the complex red pattern variation in Heliconius, population genetic analyses identify a shared 65-kb region of divergence that includes several sites perfectly associated with phenotype within each species. This region likely contains multiple cis-regulatory elements that control discrete expression domains of optix. The parallel signatures of genetic differentiation in H. erato and H. melpomene support a shared genetic architecture between the two distantly related co-mimics; however...

Mechanical damage to pollen aids nutrient acquisition in Heliconius butterflies (Nymphalidae)

Krenn, Harald W.; Eberhard, Monika J. B.; Eberhard, Stefan H.; Hikl, Anna-Laetitia; Huber, Werner; Gilbert, Lawrence E.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em 01/12/2009 EN
Relevância na Pesquisa
47.35%
Neotropical Heliconius and Laparus butterflies actively collect pollen onto the proboscis and extract nutrients from it. This study investigates the impact of the processing behaviour on the condition of the pollen grains. Pollen samples (n = 72) were collected from proboscides of various Heliconius species and Laparus doris in surrounding habitats of the Tropical Research Station La Gamba (Costa Rica). Examination using a light microscope revealed that pollen loads contained 74.88 ± 53.67% of damaged Psychotria pollen, 72.04 ± 23.4% of damaged Psiguria/Gurania pollen, and 21.35 ± 14.5% of damaged Lantana pollen (numbers represent median ± first quartile). Damaged pollen grains showed deformed contours, inhomogeneous and/or leaking contents, or they were empty. Experiments with Heliconius and Laparus doris from a natural population in Costa Rica demonstrated that 200 min of pollen processing behaviour significantly increased the percentage of damaged pollen of Psychotria compared to pollen from anthers (P = 0.015, Z = −2.44, Mann–Whitney U-test). Examination of pollen loads from green house reared Heliconius butterflies resulted in significantly greater amounts of damaged Psiguria pollen after 200 min of processing behaviour compared to pollen from flowers (P < 0.001...

Highly conserved gene order and numerous novel repetitive elements in genomic regions linked to wing pattern variation in Heliconius butterflies

Papa, Riccardo; Morrison, Clayton M; Walters, James R; Counterman, Brian A; Chen, Rui; Halder, Georg; Ferguson, Laura; ffrench-Constant, Richard; Kapan, Durrell D; Jiggins, Chris D; Chamberlain, Nicola L; Reed, Robert D.; McMillan, William O.
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
EN_US
Relevância na Pesquisa
47.33%
Background: With over 20 parapatric races differing in their warningly colored wing patterns, the butterfly Heliconius erato provides a fascinating example of an adaptive radiation. Together with matching races of its co-mimic Heliconius melpomene, H. erato also represents a textbook case of Müllerian mimicry, a phenomenon where common warning signals are shared amongst noxious organisms. It is of great interest to identify the specific genes that control the mimetic wing patterns of H. erato and H. melpomene. To this end we have undertaken comparative mapping and targeted genomic sequencing in both species. This paper reports on a comparative analysis of genomic sequences linked to color pattern mimicry genes in Heliconius. Results: Scoring AFLP polymorphisms in H. erato broods allowed us to survey loci at approximately 362 kb intervals across the genome. With this strategy we were able to identify markers tightly linked to two color pattern genes: D and Cr, which were then used to screen H. erato BAC libraries in order to identify clones for sequencing. Gene density across 600 kb of BAC sequences appeared relatively low, although the number of predicted open reading frames was typical for an insect. We focused analyses on the D- and Cr-linked H. erato BAC sequences and on the Yb-linked H. melpomene BAC sequence. A comparative analysis between homologous regions of H. erato (Cr-linked BAC) and H. melpomene (Yb-linked BAC) revealed high levels of sequence conservation and microsynteny between the two species. We found that repeated elements constitute 26% and 20% of BAC sequences from H. erato and H. melpomene respectively. The majority of these repetitive sequences appear to be novel...

Estrutura genética populacional de Heliconius erato e Heliconius melpomene (Lepidoptera: Nymphalidae) em fragmentos de Mata Atlântica do Rio Grande do Norte

Moura, Priscila Albuquerque de
Fonte: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Ecologia; Bioecologia Aquática Publicador: Universidade Federal do Rio Grande do Norte; BR; UFRN; Programa de Pós-Graduação em Ecologia; Bioecologia Aquática
Tipo: Dissertação Formato: application/pdf
POR
Relevância na Pesquisa
47.63%
Extensive studies using molecular markers on butterflies have shown how a highly fragmented landscape may result in the reduction of gene flow among patches of habitat and, consequently, increase genetic differentiation among populations. However, little is known about Heliconius geographical structure and the effects of fragmentation on the connectivity of populations. Furthermore, findings on the effects of the population structure on the dynamics of mimicry evolution in Heliconius butterflies need to be tested in H. erato and H. melpomene specimens found in other locations other than Central and northern South Americas. For the present study, we had two motivations: (1) compare the population structure of H. erato and H. melpomene given the highly fragmented Brazil s Atlantic Forest habitat; and (2) studying population structure of co-mimics could give us insights into the dynamics of mimicry evolution. For this, we analysed the spatial structure and connectivity of eight populations of Heliconius butterflies, in a total of 137 H. erato specimens and 145 H. melpomene specimens, using nine microsatellites loci, 1144 AFLPs markers and 282 mitochondrial DNA sequences. In general, both species exhibited evidence of population subdivision but no isolation by distance indicating some extent of genetic differentiation among populations. Contrary to Kronforst & Gilbert s (2008) Costa Rican Heliconius...

Adaptive introgression across species boundaries in heliconius butterflies

Pardo-Diaz, C.; Salazar, C.; Baxter, S.; Merot, C.; Figueiredo-Ready, W.; Joron, M.; McMillan, W.; Jiggins, C.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
57.13%
It is widely documented that hybridisation occurs between many closely related species, but the importance of introgression in adaptive evolution remains unclear, especially in animals. Here, we have examined the role of introgressive hybridisation in transferring adaptations between mimetic Heliconius butterflies, taking advantage of the recent identification of a gene regulating red wing patterns in this genus. By sequencing regions both linked and unlinked to the red colour locus, we found a region that displays an almost perfect genotype by phenotype association across four species, H. melpomene, H. cydno, H. timareta, and H. heurippa. This particular segment is located 70 kb downstream of the red colour specification gene optix, and coalescent analysis indicates repeated introgression of adaptive alleles from H. melpomene into the H. cydno species clade. Our analytical methods complement recent genome scale data for the same region and suggest adaptive introgression has a crucial role in generating adaptive wing colour diversity in this group of butterflies.; Carolina Pardo-Diaz, Camilo Salazar, Simon W. Baxter, Claire Merot, Wilsea Figueiredo-Ready, Mathieu Joron, W. Owen McMillan and Chris D. Jiggins

Convergent evolution in the genetic basis of Müllerian mimicry in Heliconius butterflies; Convergent evolution in the genetic basis of Mullerian mimicry in Heliconius butterflies

Baxter, S.; Papa, R.; Chamberlain, N.; Humphray, S.; Joron, M.; Morrison, C.; ffrench-Constant, R.; McMillan, W.; Jiggins, C.
Fonte: Genetics Publicador: Genetics
Tipo: Artigo de Revista Científica
Publicado em //2008 EN
Relevância na Pesquisa
47.28%
The neotropical butterflies Heliconius melpomene and H. erato are Müllerian mimics that display the same warningly colored wing patterns in local populations, yet pattern diversity between geographic regions. Linkage mapping has previously shown convergent red wing phenotypes in these species are controlled by loci on homologous chromosomes. Here, AFLP bulk segregant analysis using H. melpomene crosses identified genetic markers tightly linked to two red wing-patterning loci. These markers were used to screen a H. melpomene BAC library and a tile path was assembled spanning one locus completely and part of the second. Concurrently, a similar strategy was used to identify a BAC clone tightly linked to the locus controlling the mimetic red wing phenotypes in H. erato. A methionine rich storage protein (MRSP) gene was identified within this BAC clone, and comparative genetic mapping shows red wing color loci are in homologous regions of the genome of H. erato and H. melpomene. Subtle differences in these convergent phenotypes imply they evolved independently using somewhat different developmental routes, but are nonetheless regulated by the same switch locus. Genetic mapping of MRSP in a third related species, the "tiger" patterned H. numata...

Genetic evidence for hybrid trait speciation in Heliconius butterflies

Salazar, C.; Baxter, S.; Pardo-Diaz, C.; Wu, G.; Surridge, A.; Linares, M.; Bermingham, E.; Jiggins, C.
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
57.35%
Homoploid hybrid speciation is the formation of a new hybrid species without change in chromosome number. So far, there has been a lack of direct molecular evidence for hybridization generating novel traits directly involved in animal speciation. Heliconius butterflies exhibit bright aposematic color patterns that also act as cues in assortative mating. Heliconius heurippa has been proposed as a hybrid species, and its color pattern can be recreated by introgression of the H. m. melpomene red band into the genetic background of the yellow banded H. cydno cordula. This hybrid color pattern is also involved in mate choice and leads to reproductive isolation between H. heurippa and its close relatives. Here, we provide molecular evidence for adaptive introgression by sequencing genes across the Heliconius red band locus and comparing them to unlinked wing patterning genes in H. melpomene, H. cydno, and H. heurippa. 670 SNPs distributed among 29 unlinked coding genes (25,847bp) showed H. heurippa was related to H. c. cordula or the three species were intermixed. In contrast, among 344 SNPs distributed among 13 genes in the red band region (18,629bp), most showed H. heurippa related with H. c. cordula, but a block of around 6,5kb located in the 3′ of a putative kinesin gene grouped H. heurippa with H. m. melpomene...

Genomic hotspots for adaptation: the population genetics of Müllerian mimicry in the Heliconius melpomene clade; Genomic hotspots for adaptation: the population genetics of Mullerian mimicry in the Heliconius melpomene clade

Baxter, S.; Nadeau, N.; Maroja, L.; Wilkinson, P.; Counterman, B.; Dawson, A.; Beltran, M.; Perez-Espona, S.; Chamberlain, N.; Ferguson, L.; Clark, R.; Davidson, C.; Glithero, R.; Mallet, J.; McMillan, W.; Kronforst, M.; Joron, M.; ffrench-Constant, R.; J
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
47.27%
Wing patterning in Heliconius butterflies is a longstanding example of both Müllerian mimicry and phenotypic radiation under strong natural selection. The loci controlling such patterns are “hotspots” for adaptive evolution with great allelic diversity across different species in the genus. We characterise nucleotide variation, genotype-by-phenotype associations, linkage disequilibrium, and candidate gene expression at two loci and across multiple hybrid zones in Heliconius melpomene and relatives. Alleles at HmB control the presence or absence of the red forewing band, while alleles at HmYb control the yellow hindwing bar. Across HmYb two regions, separated by ~100 kb, show significant genotype-by-phenotype associations that are replicated across independent hybrid zones. In contrast, at HmB a single peak of association indicates the likely position of functional sites at three genes, encoding a kinesin, a G-protein coupled receptor, and an mRNA splicing factor. At both HmYb and HmB there is evidence for enhanced linkage disequilibrium (LD) between associated sites separated by up to 14 kb, suggesting that multiple sites are under selection. However, there was no evidence for reduced variation or deviations from neutrality that might indicate a recent selective sweep...

Genomic islands of divergence in hybridizing Heliconius butterflies identified by large-scale targeted sequencing

Nadeau, N.; Whibley, A.; Jones, R.; Davey, J.; Dasmahapatra, K.; Baxter, S.; Quail, M.; Joron, M.; ffrench-Constant, R.; Blaxter, M.; Mallet, J.; Jiggins, C.
Fonte: Royal Soc London Publicador: Royal Soc London
Tipo: Artigo de Revista Científica
Publicado em //2012 EN
Relevância na Pesquisa
57.27%
Heliconius butterflies represent a recent radiation of species, in which wing pattern divergence has been implicated in speciation. Several loci that control wing pattern phenotypes have been mapped and two were identified through sequencing. These same gene regions play a role in adaptation across the whole Heliconius radiation. Previous studies of population genetic patterns at these regions have sequenced small amplicons. Here, we use targeted next-generation sequence capture to survey patterns of divergence across these entire regions in divergent geographical races and species of Heliconius. This technique was successful both within and between species for obtaining high coverage of almost all coding regions and sufficient coverage of non-coding regions to perform population genetic analyses. We find major peaks of elevated population differentiation between races across hybrid zones, which indicate regions under strong divergent selection. These ‘islands’ of divergence appear to be more extensive between closely related species, but there is less clear evidence for such islands between more distantly related species at two further points along the ‘speciation continuum’. We also sequence fosmid clones across these regions in different Heliconius melpomene races. We find no major structural rearrangements but many relatively large (greater than 1 kb) insertion/deletion events (including gain/loss of transposable elements) that are variable between races.; Nicola J. Nadeau...

Genomic architecture of adaptive color pattern divergence and convergence in Heliconius butterflies

Supple, Megan A.; Hines, Heather M.; Dasmahapatra, Kanchon K.
Fonte: Universidade do Rosário Publicador: Universidade do Rosário
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/acceptedVersion Formato: application/pdf
Publicado em //2013 ENG
Relevância na Pesquisa
47.3%
Identifying the genetic changes driving adaptive variation in natural populations is key to understanding the origins of biodiversity. The mosaic of mimetic wing patterns in Heliconius butterflies makes an excellent system for exploring adaptive variation using next-generation sequencing. In this study, we use a combination of techniques to annotate the genomic interval modulating red color pattern variation, identify a narrow region responsible for adaptive divergence and convergence in Heliconius wing color patterns, and explore the evolutionary history of these adaptive alleles. We use whole genome resequencing from four hybrid zones between divergent color pattern races of Heliconius erato and two hybrid zones of the co-mimic Heliconius melpomene to examine genetic variation across 2.2 Mb of a partial reference sequence. In the intergenic region near optix, the gene previously shown to be responsible for the complex red pattern variation in Heliconius, population genetic analyses identify a shared 65-kb region of divergence that includes several sites perfectly associated with phenotype within each species. This region likely contains multiple cis-regulatory elements that control discrete expression domains of optix. The parallel signatures of genetic differentiation in H. erato and H. melpomene support a shared genetic architecture between the two distantly related co-mimics; however...

Sex Chromosome Dosage Compensation in Heliconius Butterflies: Global yet Still Incomplete?

Walters, James R.; Hardcastle, Thomas J.; Jiggins, Chris D.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Artigo de Revista Científica
Publicado em 02/09/2015 EN
Relevância na Pesquisa
47.35%
The evolution of heterogametic sex chromosomes is often—but not always—accompanied by the evolution of dosage compensating mechanisms that mitigate the impact of sex-specific gene dosage on levels of gene expression. One emerging view of this process is that such mechanisms may only evolve in male-heterogametic (XY) species but not in female-heterogametic (ZW) species, which will consequently exhibit “incomplete” sex chromosome dosage compensation. However, recent results suggest that at least some Lepidoptera (moths and butterflies) may prove to be an exception to this prediction. Studies in bombycoid moths indicate the presence of a chromosome-wide epigenetic mechanism that effectively balances Z chromosome gene expression between the sexes by reducing Z-linked expression in males. In contrast, strong sex chromosome dosage effects without any reduction in male Z-linked expression were previously reported in a pyralid moth, suggesting a lack of any such dosage compensating mechanism. Here we report an analysis of sex chromosome dosage compensation in Heliconius butterflies, sampling multiple individuals for several different adult tissues (head, abdomen, leg, mouth, and antennae). Methodologically, we introduce a novel application of linear mixed-effects models to assess dosage compensation...

Genetic architecture and ecological speciation in Heliconius butterflies

Merrill, Richard
Fonte: University of Cambridge; Department of Zoology Publicador: University of Cambridge; Department of Zoology
Tipo: Thesis; doctoral; PhD
EN
Relevância na Pesquisa
47.39%
Second half of final page redacted as it contained the beginning of the following article in 'Current Biology'; It is now widely accepted that adaptation to different ecological niches can result in the evolution of new species. However, when gene flow persists speciation must overcome the antagonism between selection and recombination: Specifically, if gene flow persists, recombination will break down the genetic associations between alleles that characterise emerging species and cause reproductive isolation. Accordingly, genetic architectures that impede recombination can slow the breakdown of linkage disequilibrium and facilitate speciation. Mimicry in tropical butterflies has long been championed as an example of adaptation driving speciation. In the Neotropical genus Heliconius, distantly related pairs of unpalatable species often converge on the same bright warning-pattern to more efficiently advertise their distastefulness to predators. In contrast, closely related taxa often belong to different mimicry rings. The sister species, Heliconius melpomene and H. cydno are sympatric across much of Central and northern South America. Using artificial butterflies I reveal selection against non-mimetic hybrid colour patterns between these two species. These colour patterns are also used as mating cues and mimetic shifts may cause both pre-mating and post-mating isolation. However...

Sex chromosome dosage compensation in Heliconius butterflies: global yet still incomplete?

Walters, James R.; Hardcastle, Thomas J.; Jiggins, Chris D.
Fonte: OUP Publicador: OUP
Tipo: Article; published version
EN
Relevância na Pesquisa
57.39%
This is the final version of the article. It first appeared from Oxford University Press via http://dx.doi.org/10.1093/gbe/evv156.; The evolution of heterogametic sex chromosomes is often?but not always?accompanied by the evolution of dosage compensating mechanisms that mitigate the impact of sex-specific gene dosage on levels of gene expression. One emerging view of this process is that such mechanisms may only evolve in male-heterogametic (XY) species but not in female-heterogametic (ZW) species, which will consequently exhibit ?incomplete? sex chromosome dosage compensation. However, recent results suggest that at least some Lepidoptera (moths and butterflies) may prove to be an exception to this prediction. Studies in bombycoid moths indicate the presence of a chromosome-wide epigenetic mechanism that effectively balances Z chromosome gene expression between the sexes by reducing Z-linked expression in males. In contrast, strong sex chromosome dosage effects without any reduction in male Z-linked expression were previously reported in a pyralid moth, suggesting a lack of any such dosage compensating mechanism. Here we report an analysis of sex chromosome dosage compensation in Heliconius butterflies, sampling multiple individuals for several different adult tissues (head...

The diversification of Heliconius butterflies: what have we learned in 150 years?

Merrill, R. M.; Dasmahapatra, K. K.; Davey, J. W.; Dell'Aglio, D. D.; Hanly, J. J.; Huber, B.; Jiggins, C. D.; Joron, M.; Kozak, K. M.; Llaurens, V.; Martin, S. H.; Montgomery, S. H.; Morris, J.; Nadeau, N. J.; Pinharanda, A. L.; Rosser, N.; Thompson, M.
Fonte: Wiley Publicador: Wiley
Tipo: Article; accepted version
EN
Relevância na Pesquisa
47.39%
This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1111/jeb.12672; Research into Heliconius butterflies has made a significant contribution to evolutionary biology. Here we review our understanding of the diversification of these butterflies, covering recent advances and a vast foundation of earlier work. While no single group of organisms can be sufficient for understanding life?s diversity, after years of intensive study, research into Heliconius has addressed a wide variety of evolutionary questions. We first discuss evidence for widespread gene flow between Heliconius species and what this reveals about the nature of species. We then address the evolution and diversity of warning patterns, both as the target of selection and with respect to their underlying genetic basis. The identification of major genes involved in mimetic shifts, and homology at these loci between distantly related taxa, has revealed a surprising predictability in the genetic basis of evolution. In the final sections, we consider the evolution of warning patterns, and Heliconius diversity more generally, within a broader context of ecological and sexual selection. We consider how different traits and modes of selection can interact and influence the evolution of reproductive isolation.; RMM is funded by a Junior Research Fellowship at King?s College...

Pollen feeding proteomics: Salivary proteins of the passion flower butterfly, Heliconius melpomene

Harpel, Desiree; Cullen, Darron A.; Ott, Swidbert R.; Jiggins, Chris D.; Walters, James R.
Fonte: Elsevier Publicador: Elsevier
Tipo: Article; accepted version
EN
Relevância na Pesquisa
47.45%
This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.ibmb.2015.04.004; While most adult Lepidoptera use flower nectar as their primary food source, butterflies in the genus Heliconius have evolved the novel ability to acquire amino acids from consuming pollen. Heliconius butterflies collect pollen on their proboscis, moisten the pollen with saliva, and use a combination of mechanical disruption and chemical degradation to release free amino acids that are subsequently re-ingested in the saliva. Little is known about the molecular mechanisms of this complex pollen feeding adaptation. Here we report an initial shotgun proteomic analysis of saliva from Heliconius melpomene. Results from liquid-chromatography tandem mass-spectrometry confidently identified 31 salivary proteins, most of which contained predicted signal peptides, consistent with extracellular secretion. Further bioinformatic annotation of these salivary proteins indicated the presence of four distinct functional classes: proteolysis (10 proteins), carbohydrate hydrolysis (5), immunity (6), and ?housekeeping? (4). Additionally, six proteins could not be functionally annotated beyond containing a predicted signal sequence. The presence of several salivary proteases is consistent with previous demonstrations that Heliconius saliva has proteolytic capacity. It is likely that these proteins play a key role in generating free amino acids during pollen digestion. The identification of proteins functioning in carbohydrate hydrolysis is consistent with Heliconius butterflies consuming nectar...