Transcriptome Study And GST Gene Family Analysis Of Pomacea Canaliculata Under Metaldehyde Stress

Pomacea canaliculata originated from south America is one of the 100 th of the world's worst invasive alien species.P.canaliculata is mainly distributed in the south of China,which seriously threatens aquatic crops such as rice in the invaded area,causing huge damage to agricultural production and ecological environment.Molluscicide is mainly used to control P.canaliculata and studies have shown that continuous application of metaldehyde will cause resistance.In the present study,we conducted the acute toxic test on P.canaliculata,compared the transcriptome of hepatopancreas in female and mele P.canaliculata,and identified the GST gene family in P.canaliculata.This study provides a theoretical basis to elucidate molecular regulation mechanism of P.canaliculata in response to metaldehyde stress and effective control of P.canaliculata.The major results of this study are as follows:1.Hepatopancreas of P.canaliculata was observed by light microscope after exposure to metaldehyde.The result suggested that exposure to metaldehyde caused deformation of the digestive tubules in male and female snails,increased in number of basophilic cells,black particles and hemocyte,epithelial cells atrophy.These changes may be related to the dose and exposure time.No significant difference was observed in the hepatopancreas histology between male and female snails.2.Comparing transcriptome of hepatopancreas in female and male P.canaliculata under short-term of metaldehyde stress,most genes related to exogenous metabolism,transport and energy,and endogenous substance metabolism were upregulated.There were 211 differentially expressed genes in the female snail of control group and treatment group,of which 95 were up-regulated and 116 were downregulated.The number of differentially expressed genes in the male snail of control group and treatment group was 331,of which 143 were up-regulated and 188 were down-regulated.Differentially expressed genes in the whole control group and treatment group were used for GO enrichment analysis.Up-regulated genes were mainly enriched in 30 items,and down-regulated genes were mainly enriched in 33 items.These items involved functions such as metabolic process,cell membrane and catalytic activity.These results suggested that metaldehyde has a significant effect on the physiological state of P.canaliculata.KEGG pathway enrichment analysis further suggested that the differential genes were significantly enriched in pathways related to the metabolism of endogenous and exogenous substances and energy metabolism.3.A total of 28 GST genes were identified in the genome of P.canaliculata using sequence search and phylogenetic analysis.These genes belonging to six different subfamilies: Alpha,Theta,Zeta,Sigma,Mu,and MAPEG.Genes of each subfamily are relatively conservative except for the Alpha subclass.The members of the Theta and Sigma subclasses have most members in the GST family of P.canaliculata.The GST gene is mainly distributed in the nine chromosomes of P.canaliculata with an uneven distribution.