Transcriptome Sequencing For Identification Of Diapause-associated Genes And Genetic Differentiation Of Hyphantria Cunea (Drury)

Fall webworm（Hyphantria cunea,Lepidoptera:Arctiidae）,originated in North America.With the human activities,It has invaded to many countries and become a worldwide quarantine pests which cause serious disasters.In order to explore the genes related to diapause of fall webworm,high-throughput RNA-Seq data were generated from non-diapause pupae and diapause pupae of Shenyang.Differentially expressed genes（DEGs）and diapause-associated genes were obtained after comparison and selecting.In addition,to study the relationship among different different geographical populations of fall webworm,mtDNA COI of different geographical populations were sequenced.Also the COI sequence of Canadian and Hungarian populations from GeneBank was combined with our results.The phylogenetic relationships of fall webworm were established based on COI sequences.The conclusions of two parts were as follows:1.After sequencing and filtering,a total of 58,151 unigenes were assembled and 21,689 of them were annotated in 9 public databases.According to the annotations,Nr database had the largest match（20,872,35.89%）,the top match was obtained by Bombyx mori,with7596 sequences（36.39%）.16,734 unigenes（28.78%）were categorized into 61sub-categories under 3 main GO categories.A total of 3,225 unigenes were annotated against KEGG database and assigned to 332 pathways.2.32,464 DGEs（FDR≤0.001and log₂|Fold change|>1）were filtered.Among the DEGs,29,013 up-regulated and 3,451 down-regulated DGEs were revealed.Based on the transcriptome analysis and referring to the existing research results,MCM2,JHAMT,PRPCK,HSP20,FOXO3,PIK3R,SDH2 and other diapause related genes were filtered.3.Sequencing the COI sequences of the samples of 5 provinces or cities of China（10spots）and 12 states of America（including red head type and black head type）,a total of 28COI sequences of 709bp with 46 variable sites were obtained.the phylogenetic trees were built based on the Kimura-2-Parameter model by the maximum likelihood method and the adjacency method.The results showed that there were great differences between the red head type and black head type,except for the black head type in Wisconsin and North Carolina,and the COI sequences’differentiation of the Chinese populations was not obvious.4.Combined COI sequence of Canadian and Hungarian populations of GeneBank with our results,40 COI partial sequences of 519bp with 35 variable sites were acquired.The same method was used to construct the phylogenetic trees.It was known that the fall webworm populations in the East and Middle East of the United States,the southeast of Canada and China can be clustered.