title: Analysis of midgut gene expression profiles from different silkworm varieties after exposure to high temperature.
abstract: The silkworm is a poikilothermic animal, whose growth and development is significantly influenced by environmental temperature. To identify genes and metabolic pathways involved in the heat-stress response, digital gene expression analysis was performed on the midgut of the thermotolerant silkworm variety '932' and thermosensitive variety 'HY' after exposure to high temperature (932T and HYT). Deep sequencing yielded 6,211,484, 5,898,028, 5,870,395 and 6,088,303 reads for the 932, 932T, HY and HYT samples, respectively. The annotated genes associated with these tags numbered 4357, 4378, 4296 and 4658 for the 932, 932T, HY and HYT samples, respectively. In the HY-vs-932, 932-vs-932T, and HY-vs-HYT comparisons, 561, 316 and 281 differentially expressed genes were identified, which could be assigned to 179, 140 and 123 biological pathways, respectively. It was found that some of the biological pathways, which included oxidative phosphorylation, related to glucose and lipid metabolism, are greatly affected by high temperature and may lead to a decrease in the ingestion of fresh mulberry. When subjected to an early period of continuous heat stress, HSP genes, such as HSP19.9, HSP23.7, HSP40-3, HSP70, HSP90 and HSP70 binding protein, are up-regulated but then reduced after 24h and the thermotolerant '932' strain has higher levels of mRNA of some HSPs, except HSP70, than the thermosensitive variety during continuous high temperature treatment. It is suggested that HSPs and the levels of their expression may play important roles in the resistance to high temperature stress among silkworm varieties. This study has generated important reference tools that can be used to further analyze the mechanisms that underlie thermotolerance differences among silkworm varieties.
authors.affiliation: The Sericulture and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, GuangZhou, China.
authors.forename: Qing Rong
authors.initials: QR
authors.lastname: Li
authors.affiliation: The Sericulture and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, GuangZhou, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Xiao
authors.affiliation: The Sericulture and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, GuangZhou, China.
authors.forename: Fu Quan
authors.initials: FQ
authors.lastname: Wu
authors.affiliation: The Sericulture and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, GuangZhou, China.
authors.forename: Ming Qiang
authors.initials: MQ
authors.lastname: Ye
authors.affiliation: The Sericulture and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, GuangZhou, China.
authors.forename: Guo Qing
authors.initials: GQ
authors.lastname: Luo
authors.affiliation: The Sericulture and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, GuangZhou, China.
authors.forename: Dong Xu
authors.initials: DX
authors.lastname: Xing
authors.affiliation: The Sericulture and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, GuangZhou, China.
authors.forename: Li
authors.initials: L
authors.lastname: Li
authors.affiliation: The Sericulture and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, GuangZhou, China. Electronic address: serilover@126.com.
authors.forename: Qiong
authors.initials: Q
authors.lastname: Yang
mesh_terms: D000220:Adaptation, Biological; D000818:Animals; D012831:Bombyx / Q000145:classification / Q000235:genetics* / Q000254:growth & development / Q000502:physiology; D041981:Gastrointestinal Tract / Q000378:metabolism*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D017344:Genes, Insect; D006360:Heat-Shock Proteins / Q000235:genetics*; D018869:Heat-Shock Response; D007814:Larva / Q000235:genetics; D053858:Metabolic Networks and Pathways; D031625:Morus / Q000378:metabolism
chemical_list: D006360:Heat-Shock Proteins
keywords: Digital gene expression; High temperature; Midgut; Silkworm