Diapause is a programmed developmental arrest process in insects.Diapause can occur at various stages of insect development and is frequently restricted to a specific developmental stage within a single species.In Bom...Diapause is a programmed developmental arrest process in insects.Diapause can occur at various stages of insect development and is frequently restricted to a specific developmental stage within a single species.In Bombyx mori,embryonic diapause is elicited by the diapause hormone(DH)and DH receptor(DHR)in diapause strains.Nevertheless,the regulatory mechanism through which BmDHR functions as a G protein-coupled receptor(GPCR),to exert other physiological functions in nondiapause silkworms,remains unclear.In this study,we found that BmDHR had 7 alternative splice isoforms.A knockout experiment confirmed that BmDHR mediated the transduction of diapause signals.Interestingly,the loss of BmDHR caused partial precocious metamorphosis and an embryo-lethal phenotype in nondiapause silkworms.An assessment of global transcriptional patterns revealed that BmDHR knockout affected physiological responses induced by manifold cellular processes,including the Toll/immune deficiency(Imd),Wnt,insulin-like growth factor,Hedgehog and P38/mitogen-activated protein kinase(MAPK)signaling pathways.This study expands our knowledge of the physiological roles for DHR in insect growth and development.展开更多
[Objectives]The present study was conducted to investigate the change rule ofβ-fructofuranosidase gene expression and its enzyme activity in the midgut of 5 th instar silkworm(Bombyx mori),in order to provide a refer...[Objectives]The present study was conducted to investigate the change rule ofβ-fructofuranosidase gene expression and its enzyme activity in the midgut of 5 th instar silkworm(Bombyx mori),in order to provide a reference for illustrating the enzymatic mechanism of usingβ-fructofuranosidase to absorb sucrose nutrition from mulberry leaves.[Methods]Real-time fluorescent quantitative PCR was applied to analyze the expression of BmSuc1 and BmSuc2 in midgut of 5 th-instar silkworm larvae,meanwhile the activities ofβ-fructofuranosidase was determined.[Results]BmSuc1 was expressed in the midgut of 5 th-instar silkworm larvae at different developmental stages.Its expression was upregulated at the beginning of the 5 th instar and during the peak feeding period,whereas BmSuc2 expression remained very low throughout the entire 5 th instar.The activity ofβ-fructofuranosidase was relatively high during the peak feeding period of 5 th-instar larvae,showing a trend of increasing first and then decreasing.[Conclusions]The expression pattern of the BmSuc1 gene and the changes inβ-fructofuranosidase activity were generally consistent with the physiological process of sugar nutrient absorption and utilization from mulberry leaves in 5 th-instar silkworms.It suggests that BmSuc1,as a sucrose hydrolase gene,plays a major role in the digestion and absorption of sucrose nutrients from mulberry leaves in the midgut tissue.展开更多
桑枝是桑科植物桑(Mrous alba L.)的干燥嫩枝,具有祛风湿、利关节等功效,现代研究发现生物碱是桑枝中的主要活性物质。本文以高脂饮食小鼠为模型研究桑枝生物碱(SZ-A)对降脂的功效。实验结果表明:饲喂高脂饲料16周后,小鼠体重显著上升;...桑枝是桑科植物桑(Mrous alba L.)的干燥嫩枝,具有祛风湿、利关节等功效,现代研究发现生物碱是桑枝中的主要活性物质。本文以高脂饮食小鼠为模型研究桑枝生物碱(SZ-A)对降脂的功效。实验结果表明:饲喂高脂饲料16周后,小鼠体重显著上升;总生物碱干预后,SZ-A组小鼠体重显著低于模型组;理化指标分析发现,总生物碱显著降低了HFD小鼠血脂(TG、TC、LDL-C)、谷丙转氨酶、谷草转氨酶活性,有效缓解高脂饮食导致的小鼠肝脏病变;RT-PCR结果显示,总生物碱具有抑制CD36/PPARγ介导的脂质摄取,激活AMPK/ACC通路促进脂肪酸氧化,抑制SREBP1核转位减少脂质合成等降脂活性。本实验结果表明,桑枝生物碱SZ-A具有良好的降脂功效,能激活CD36/PPARγ与AMPK/ACC通路,抑制下游脂质代谢相关基因表达,发挥降脂功效和肝脏保护作用。展开更多
基金supported by the National Natural Science Foundation of China(32170483 and 31970460)the Natural Science Foundation of Zhejiang Province(LR22C040001 and LQ23C040001)the Zhejiang Province Agricultural Technology Major Collaborative Promotion Project(2024ZDXT09).
文摘Diapause is a programmed developmental arrest process in insects.Diapause can occur at various stages of insect development and is frequently restricted to a specific developmental stage within a single species.In Bombyx mori,embryonic diapause is elicited by the diapause hormone(DH)and DH receptor(DHR)in diapause strains.Nevertheless,the regulatory mechanism through which BmDHR functions as a G protein-coupled receptor(GPCR),to exert other physiological functions in nondiapause silkworms,remains unclear.In this study,we found that BmDHR had 7 alternative splice isoforms.A knockout experiment confirmed that BmDHR mediated the transduction of diapause signals.Interestingly,the loss of BmDHR caused partial precocious metamorphosis and an embryo-lethal phenotype in nondiapause silkworms.An assessment of global transcriptional patterns revealed that BmDHR knockout affected physiological responses induced by manifold cellular processes,including the Toll/immune deficiency(Imd),Wnt,insulin-like growth factor,Hedgehog and P38/mitogen-activated protein kinase(MAPK)signaling pathways.This study expands our knowledge of the physiological roles for DHR in insect growth and development.
基金Supported by General Project of Yunnan Provincial Agricultural Basic Research Joint Special Project(202301BD070001-229)Yunnan Provincial Key R&D Program(202403AK140075)+1 种基金Modern Sericulture Industry Technology System of Yunan Province(KJTX-07)Honghe Comprehensive Test Station of National Sericulture Industry Technology System(CARS-18).
文摘[Objectives]The present study was conducted to investigate the change rule ofβ-fructofuranosidase gene expression and its enzyme activity in the midgut of 5 th instar silkworm(Bombyx mori),in order to provide a reference for illustrating the enzymatic mechanism of usingβ-fructofuranosidase to absorb sucrose nutrition from mulberry leaves.[Methods]Real-time fluorescent quantitative PCR was applied to analyze the expression of BmSuc1 and BmSuc2 in midgut of 5 th-instar silkworm larvae,meanwhile the activities ofβ-fructofuranosidase was determined.[Results]BmSuc1 was expressed in the midgut of 5 th-instar silkworm larvae at different developmental stages.Its expression was upregulated at the beginning of the 5 th instar and during the peak feeding period,whereas BmSuc2 expression remained very low throughout the entire 5 th instar.The activity ofβ-fructofuranosidase was relatively high during the peak feeding period of 5 th-instar larvae,showing a trend of increasing first and then decreasing.[Conclusions]The expression pattern of the BmSuc1 gene and the changes inβ-fructofuranosidase activity were generally consistent with the physiological process of sugar nutrient absorption and utilization from mulberry leaves in 5 th-instar silkworms.It suggests that BmSuc1,as a sucrose hydrolase gene,plays a major role in the digestion and absorption of sucrose nutrients from mulberry leaves in the midgut tissue.
文摘桑枝是桑科植物桑(Mrous alba L.)的干燥嫩枝,具有祛风湿、利关节等功效,现代研究发现生物碱是桑枝中的主要活性物质。本文以高脂饮食小鼠为模型研究桑枝生物碱(SZ-A)对降脂的功效。实验结果表明:饲喂高脂饲料16周后,小鼠体重显著上升;总生物碱干预后,SZ-A组小鼠体重显著低于模型组;理化指标分析发现,总生物碱显著降低了HFD小鼠血脂(TG、TC、LDL-C)、谷丙转氨酶、谷草转氨酶活性,有效缓解高脂饮食导致的小鼠肝脏病变;RT-PCR结果显示,总生物碱具有抑制CD36/PPARγ介导的脂质摄取,激活AMPK/ACC通路促进脂肪酸氧化,抑制SREBP1核转位减少脂质合成等降脂活性。本实验结果表明,桑枝生物碱SZ-A具有良好的降脂功效,能激活CD36/PPARγ与AMPK/ACC通路,抑制下游脂质代谢相关基因表达,发挥降脂功效和肝脏保护作用。
