Genomewide transcriptional signatures of migratory flight activity in a globally invasive insect pest

Migration is a key life history strategy for many animals and requires a suite of behavioural, morphological and physiological adaptations which together form the migratory syndrome'. Genetic variation has been demonstrated for many traits that make up this syndrome, but the underlying genes involved remain elusive. Recent studies investigating migration-associated genes have focussed on sampling migratory and nonmigratory populations from different geographic locations but have seldom explored phenotypic variation in a migratory trait. Here, we use a novel combination of tethered flight and next-generation sequencing to determine transcriptomic differences associated with flight activity in a globally invasive moth pest, the cotton bollworm Helicoverpa armigera. By developing a state-of-the-art phenotyping platform, we show that field-collected H.armigera display continuous variation in flight performance with individuals capable of flying up to 40km during a single night. Comparative transcriptomics of flight phenotypes drove a gene expression analysis to reveal a suite of expressed candidate genes which are clearly related to physiological adaptations required for long-distance flight. These include genes important to the mobilization of lipids as flight fuel, the development of flight muscle structure and the regulation of hormones that influence migratory physiology. We conclude that the ability to express this complex set of pathways underlines the remarkable flexibility of facultative insect migrants to respond to deteriorating conditions in the form of migratory flight and, more broadly, the results provide novel insights into the fundamental transcriptional changes required for migration in insects and other taxa

Overwintering Survival and Spring Emergence of Helicoverpa armigera (Lepidoptera: Noctuidae) in Northern Greece

Overwintering survival of Helicoverpa annigera (Hubner) was studied under field conditions during the winter of 2004-2005 and 2005-2006 to clarify whether a local population of this insect is established in northern Greece. Additionally, the postdiapause eclosion times of the overwintering generation was compared with adult male dynamics using pheromone traps. Our study supplies strong evidence that part, if not all, of the late-season generation of H armigera overwinters as diapausing pupa in northern Greece, suggesting that a local population exists in this area. Pupae enter diapause during September and October in response to declining temperatures and photoperiod. A limited number of degree-days in autumn prevented part of the population from developing to the diapausing pupal stage Larvae of H armigera that were placed in field conditions late in October were not able to pupate and died. The termination of diapause and the eclosion of adults in the following spring were determined by the local soil temperatures. Diapause terminated between mid-April and early May, and adult emergence occurred within a 4- to 6-wk period from late April to early June. Females emerged slightly earlier than the males. The emergence of 10, 25, 50, 75, and 90% of adults required 153, 199, 252, 303, and 347 DD, respectively Differences in timing and degree of overlap between adult emergence from the experimental population and pheromone trap catches suggests that the spring population of this species also includes immigrants

RNAseq read count data from China Helicoverpa armigera

The data is a matrix of read counts generated from an RNAseq analysis of six samples of H. armigera. Each RNA sample was extracted from a pool of three whole individual insects. The first column contains the gene identification number. All other column headings represent the individual samples. AY = insects from Anyang. DF = insects from Dafeng. The data was used to determine differential gene expression using the open software packages edgeR and DEseq2

Data from: Genome-wide transcriptional signatures of migratory flight activity in a globally invasive insect pest

Migration is a key life history strategy for many animals and requires a suite of behavioural, morphological and physiological adaptations which together form the ‘migratory syndrome’. Genetic variation has been demonstrated for many traits that make up this syndrome, but the underlying genes involved remain elusive. Recent studies investigating migration-associated genes have focussed on sampling migratory and nonmigratory populations from different geographic locations but have seldom explored phenotypic variation in a migratory trait. Here, we use a novel combination of tethered flight and next-generation sequencing to determine transcriptomic differences associated with flight activity in a globally invasive moth pest, the cotton bollworm Helicoverpa armigera. By developing a state-of-the-art phenotyping platform, we show that field-collected H. armigera display continuous variation in flight performance with individuals capable of flying up to 40 km during a single night. Comparative transcriptomics of flight phenotypes drove a gene expression analysis to reveal a suite of expressed candidate genes which are clearly related to physiological adaptations required for long-distance flight. These include genes important to the mobilization of lipids as flight fuel, the development of flight muscle structure and the regulation of hormones that influence migratory physiology. We conclude that the ability to express this complex set of pathways underlines the remarkable flexibility of facultative insect migrants to respond to deteriorating conditions in the form of migratory flight and, more broadly, the results provide novel insights into the fundamental transcriptional changes required for migration in insects and other taxa

Total distance flown by individual adult Helicoverpa armigera on the flight mills

Flight mill data used in all figures and REML analyses. This data is used in Fig1B, Fig1C and FigS2. Column headings and data are as follows:- ID = the flight mill channel (A or B), year flown ('13' represents 2013), date flown (e.g. Nov13 = November 13th) and mill flown (e.g. _Ch7 = mill #7). origin = origin of the insect population. sex = male (m) or female (f). Total distance flown = the total distance (metres) each individual flew on the flight mill during the course of a single night as recorded by the tethered flight mill

Identified GO terms for Helicoverpa armigera genes

The file provides a list of GO-terms used in a functional enrichment analysis for genes involved in flight activity in Helicoverpa armigera. The list was generated using BLAST-2-GO. A total of 11316 genes (from a total of 17001) have identified GO-terms

RNA-seq analysis of flight phenotypes of H. armigera - DEseq2 full output

Output from R package DEseq2 for China and Greece H. armigera RNAseq experiments analysing differential expression between flight phenotypes. Gene ID = gene identification number. baseMean = average of the normalised count values. log2FoldChange = estimated log fold change between sample groups (for China the estimate is measured against AY; for Greece the estimate is measured against GR_S). lfcSE = standard error estimate for logFC. p-value = evidence for an effect of treatment on expression. padj = multiple testing correction for p-value. 'NA' in the p-value or padj column indicates that the gene was excluded from the analysis due to no count data or an extreme outlier