Abstract: 【Aim】 To clarify the relationship between carbohydrate metabolism and diapause during the earlyembryonicdevelopmentalstageinBombyx mori. 【Methods】 Theactivatedhibernating eggs of bivoltine B. mori strain Qiufeng were used as materials. Some were incubated under 17℃ in darkness and fed normally to produce the non-diapause-destined eggs (ND), and others were incubated under 25℃ in natural circadian rhythm and fed normally to produce the diapause-destined eggs (DD), part of which were further treated with HCl solution to produce the immediately acid-treated eggs (IA). Samples were collected at 0, 2, 6, 12, 24, 48, 72, and 96 h, respectively, after oviposition or acid treatment. The mRNA levels of genes of five carbohydrate metabolism-related enzymes including hexokinase (HK), phosphofructokinase (PFK), sorbitol dehydrogenase (SDH), phosphoenolpyruvate carboxykinase (PEPCK) and trehalase (TRE) in B. mori eggs were detected by qRT-PCR, and the activities of the five enzymes in B. mori eggs were assayed by ultraviolet visible spectrophotometry. 【Results】 The overall mRNA levels and activities of the key enzymes of glycolysis,hexokinase (BmHK) and phosphofructokinase (BmPFK), and the key enzymes of glycometabolism, sorbitol dehydrogenase (BmSDH-1) and trehalase (BmTRE), in ND and IA of B. mori were higher than those in DD, while the mRNA levels and activities of phosphoenolpyruvate carboxykinase (BmPEPCK) related to gluconeogenesis in DD were higher than those in ND and IA. 【Conclusion】 The results suggest that in the early embryonic developmental stage of DD, carbohydrate metabolism is mainly towards energy and material storage for diapause, while in ND and IA, carbohydrate metabolism is mainly towards material catabolism due to fast embryonic development. This study has preliminarily uncovered the relationship between carbohydrate metabolism and diapause of B. mori, being beneficial to better understand the molecular mechanisms of diapause of B. mori.

Key words: Bombyx mori, egg, diapause, carbohydrate metabolism, transcriptional level, enzymatic activity