Project description:The purpose of this experiment was to compare RNA-seq profiles of adult male and female butterfly chemosensory tissues to identify tissue- and sex-specific differences in gustatory and olfactory gene expression. Three biological replicates per sex were produced from individual Heliconius melpomene rosina butterflies. For the antennal libraries, both antennae were used, for the labial palps + proboscis libraries both labial palps and each proboscis was used, and for the leg libraries all six legs were used.
Project description:We use RNAseq data to perform differential gene expression to identify genes controlling structural colouration in two co-mimetic species of Heliconius butterfly - Heliconius erato and Heliconius melpomene. We use comparisons between iridescent and non-iridescent subspecies of Helcionius erato (H. e. cyrbia and H. e. demophoon, respectively) and Helcionius melpomene (H. m. cythera and H. m. rosina, respectively) at two separate developmental stages, 50% and 70% of development. In addition, in the iridescent subspecies of both H. erato and H. melpomene, we compared the iridescent wing regions (forewing and hindwing combined) to the non-iridescent androconial wing region using differential gene expression.
Project description:We use RNAseq data to perform differential gene expression analysis to identify genes controlling structural colouration in two co-mimetic species of Heliconius butterfly - Heliconius erato and Heliconius melpomene. We use comparisons between iridescent and non-iridescent subspecies of Helcionius erato (H. e. cyrbia and H. e. demophoon, respectively) and Helcionius melpomene (H. m. cythera and H. m. rosina, respectively) at two separate developmental stages, 50% and 70% of development. In addition, in the iridescent subspecies of both H. erato and H. melpomene, we compared the iridescent wing regions (forewing and hindwing combined) to the non-iridescent androconial wing (anterior hindwing) region using differential gene expression.
Project description:Background: Heliconius butterflies are an excellent model system for studies of adaptive convergent and divergent phenotypic traits. Wing colour patterns are used as signals to both predators and potential mates and are inherited in a Mendelian manner. The underlying genetic mechanisms of pattern formation have been studied for many years and shed light on broad issues, such as the repeatability of evolution. In Heliconius melpomene, the yellow hindwing bar is controlled by the HmYb locus and several genes in this region show expression pattern differences across races. MicroRNAs (miRNAs) are important post-transcriptional regulators of gene expression that have key roles in many biological processes, including development. It seems likely that miRNAs could act as downstream regulators of genes involved in wing development, patterning and pigmentation. For this reason we characterised miRNAs in developing butterfly wings and examined differences in their expression between colour pattern races. Results: We sequenced small RNA libraries from two colour pattern races and detected 142 Heliconius miRNAs with homology to others found in miRBase. Several highly abundant miRNAs appeared to be differentially expressed between colour pattern races and this was tested further in different developing pupal wing stages using Northern blots. These revealed that differences in expression were due to developmental stage rather than colour pattern. Assembly of sequenced reads to the HmYb region identified miR-193 and miR-2788; located 2380bp apart in an intergenic region. A search for miRNAs in all available H. melpomene BAC sequences (~2.5Mb) did not reveal any other miRNA genes and no novel miRNAs were predicted. There were several regions where other small RNA sequences assembled to the HmYb region and appeared to be differentially expressed.These might represent other regulatory RNAs. Conclusions: Here we describe the first butterfly miRNAs and characterise their expression in developing wings. Some show differences in expression across developing pupal stages. Two miRNAs were located in the HmYb region. Future work will examine the expression of these miRNAs in different colour pattern races and identify miRNA targets among wing patterning genes. High-throughput sequencing of Heliconius melpomene endogenous small RNAs. Size fractionated small RNA from total RNA extracts of two different Heliconius melpomene races (Heliconius melpomene melpomene and Heliconius melpomene rosina) were isolated from wing tissue using miRVana kit. 100µg RNA from 11 individuals of different developmental stages was pooled for each race as follows: 4.1% larval stage <1; 2% larval stage 1-1.75; 2.9% larval stage 2-2.5; 22% larval stage 2.75-3; 19% larval stage > 3; 25% early pupae; 25% mid-melanin pupae. Sequences were ligated to adapters, purified again and reverse transcribed. After PCR amplification the sample was subjected to Solexa/Illumina high throughput pyrosequencing. Please see www.illumina.com for details of the sequencing technology.
Project description:Heliconius butterfly wing pattern diversity offers a unique opportunity to investigate how natural genetic variation can drive the evolution of complex adaptive phenotypes. Here we took a large-scale transcriptomic approach to identify the network of genes involved in Heliconius wing pattern development and variation. This included applying 147 microarrays representing the Heliconius transcriptome to assay shifts in gene expression across pupal development among several wing pattern morphs of Heliconius erato. We focused in particular on genes differentially expressed relative to the gene optix, which controls red pattern elements in wings. We combined expression results from three hindwing morphs from Peru and from dissected basal to apical wing elements in two forewing morphs to uncover two main classes of genes. First we looked for candidate upstream regulators of optix by determining transcripts expressed differently across basal to apical sections of the forewing prior to optix expression. Second, we assessed how optix regulates downstream gene expression by targeting transcripts with differential expression similar to optix, where expression differs among red wing pattern elements of both the forewing and hindwing.
Project description:Background: Heliconius butterflies are an excellent model system for studies of adaptive convergent and divergent phenotypic traits. Wing colour patterns are used as signals to both predators and potential mates and are inherited in a Mendelian manner. The underlying genetic mechanisms of pattern formation have been studied for many years and shed light on broad issues, such as the repeatability of evolution. In Heliconius melpomene, the yellow hindwing bar is controlled by the HmYb locus and several genes in this region show expression pattern differences across races. MicroRNAs (miRNAs) are important post-transcriptional regulators of gene expression that have key roles in many biological processes, including development. It seems likely that miRNAs could act as downstream regulators of genes involved in wing development, patterning and pigmentation. For this reason we characterised miRNAs in developing butterfly wings and examined differences in their expression between colour pattern races. Results: We sequenced small RNA libraries from two colour pattern races and detected 142 Heliconius miRNAs with homology to others found in miRBase. Several highly abundant miRNAs appeared to be differentially expressed between colour pattern races and this was tested further in different developing pupal wing stages using Northern blots. These revealed that differences in expression were due to developmental stage rather than colour pattern. Assembly of sequenced reads to the HmYb region identified miR-193 and miR-2788; located 2380bp apart in an intergenic region. A search for miRNAs in all available H. melpomene BAC sequences (~2.5Mb) did not reveal any other miRNA genes and no novel miRNAs were predicted. There were several regions where other small RNA sequences assembled to the HmYb region and appeared to be differentially expressed.These might represent other regulatory RNAs. Conclusions: Here we describe the first butterfly miRNAs and characterise their expression in developing wings. Some show differences in expression across developing pupal stages. Two miRNAs were located in the HmYb region. Future work will examine the expression of these miRNAs in different colour pattern races and identify miRNA targets among wing patterning genes.
Project description:We sequenced the mRNA of three species of Heliconius butterfly and Eueides isabella in order to identify genes upregulated in the mouthparts tissues. Sequencing libraries were produced for three tissues types (mouthparts, legs and antennae), for one male and one female of each species.
Project description:We test the hypothesis that intraspecific genomic divergence is linked to regulatory variation between Heliconius butterfly populations. We show that population-level divergence in chromatin accessibility and regulatory activity during wing development is abundant, and that differences in regulatory activity between populations are strongly associated with developmental stage. Genomic regions with high Fst are highly enriched for regulatory variants, and enrichment patterns vary significantly across development. Regulatory variants are associated with most differential gene expression between populations, and our data point to two roles for histone modifications in the evolution of gene expression.
Project description:We test the hypothesis that intraspecific genomic divergence is linked to regulatory variation between Heliconius butterfly populations. We show that population-level divergence in chromatin accessibility and regulatory activity during wing development is abundant, and that differences in regulatory activity between populations are strongly associated with developmental stage. Genomic regions with high Fst are highly enriched for regulatory variants, and enrichment patterns vary significantly across development. Regulatory variants are associated with most differential gene expression between populations, and our data point to two roles for histone modifications in the evolution of gene expression.
Project description:We test the hypothesis that intraspecific genomic divergence is linked to regulatory variation between Heliconius butterfly populations. We show that population-level divergence in chromatin accessibility and regulatory activity during wing development is abundant, and that differences in regulatory activity between populations are strongly associated with developmental stage. Genomic regions with high Fst are highly enriched for regulatory variants, and enrichment patterns vary significantly across development. Regulatory variants are associated with most differential gene expression between populations, and our data point to two roles for histone modifications in the evolution of gene expression.