The fat body of the holometabolous insect is remodeled by the degradation of the larval fat body and the development of the adult fat body during metamorphosis.However,the mechanism of adult fat body development is qu...The fat body of the holometabolous insect is remodeled by the degradation of the larval fat body and the development of the adult fat body during metamorphosis.However,the mechanism of adult fat body development is quite unclear.Using the agricultural pest Helicoverpa armigera,the cotton bollworm,as a model,we revealed that the development of adult fat body was regulated by glycolysis,triglyceride(triacylglycerol[TAG])synthesis,cell proliferation,and cell adhesion.RNA sequencing detected a set of genes that were upregulated in the 8-d late pupal fat body at a late metamorphic stage compared with the 2-d pupal fat body at an earlier metamorphic stage.The pathways for glycolysis,TAG synthesis,cell proliferation,and cell adhesion were enriched by the differentially expressed genes,and the key genes linked with these pathways showed increased expression in the 8-d pupal fat body.Knockdown of phosphofructokinase(Pfk),acetyl-CoA carboxylase(Acc1),phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit(P110)and collagen alpha-1(IV)chain(Col4a1)by RNA interference resulted in abnormal eclosion and death at pupal stages,and repressed lipid droplets accumulation and adult fat body development.The expression of Acc1,P110,and Col4a1 was repressed by the insect steroid hormone 20-hydroxyecdysone(20E).The critical genes in the 20E pathway appeared to decrease at the late pupal stage.These data suggested that the development of the insect adult fat body is regulated by glycolysis,lipids synthesis,cell proliferation,and cell adhesion at the late pupal stage when the 20E signal decreases.展开更多
Background In contrast to protein-rich insect meal,the feed potential of insect fat is generally less explored and knowledge about the suitability of insect fat as a fat source specifically in broiler diets is still l...Background In contrast to protein-rich insect meal,the feed potential of insect fat is generally less explored and knowledge about the suitability of insect fat as a fat source specifically in broiler diets is still limited.In view of this,the present study aimed to comprehensively investigate the effect of partial(50%) and complete replacement of soybean oil with insect fat from Hermetia illucens(HI) larvae in broiler diets on performance,fat digestibility,cecal microbiome,liver transcriptome and liver and plasma lipidomes.Thus,100 male,1-day-old Cobb 500 broilers were randomly assigned to three groups and fed three different diets with either 0(group HI-0,n cens(HI) larvae fat for 35 d.= 30),2.5%(group HI-2.5,n %(HI-5.0,n = 35) or 5.0= 35) Hermetia illuResults Body weight gain,final body weight,feed intake,and feed:gain ratio during the whole period and apparent ileal digestibility coefficient for ether extract were not different between groups.Cecal microbial diversity did not differ between groups and taxonomic analysis revealed differences in the abundance of only four low-abundance bacterial taxa among groups;the abundances of phylum Actinobacteriota,class Coriobacteriia,order Coriobacteriales and family Eggerthellaceae were lower in group HI-5.0 compared to group HI-2.5(P < 0.05).Concentrations of total and individual short-chain fatty acids in the cecal digesta were not different between the three groups.Liver transcriptomics revealed a total of 55 and 25 transcripts to be differentially expressed between groups HI-5.0 vs.HI-0 and groups HI-2.5 vs.HI-0,respectively(P < 0.05).The concentrations of most lipid classes,with the exception of phosphatidylethanolamine,phosphatidylglycerol and lysophosphatidylcholine in the liver and cholesterylester and ceramide in plasma(P < 0.05),and of the sum of all lipid classes were not different between groups.Conclusions Partial and complete replacement of soybean oil with HI larvae fat in broiler diets had no effect on growth performance and only modest,but no adverse effects on the cecal microbiome and the metabolic health of broilers.This suggests that HI larvae fat can be used as an alternative fat source in broiler diets,thereby,making broiler production more sustainable.展开更多
基金supported by grants from the National Natural Science Foundation of China(Grant Nos.32270507 and 32330011).
文摘The fat body of the holometabolous insect is remodeled by the degradation of the larval fat body and the development of the adult fat body during metamorphosis.However,the mechanism of adult fat body development is quite unclear.Using the agricultural pest Helicoverpa armigera,the cotton bollworm,as a model,we revealed that the development of adult fat body was regulated by glycolysis,triglyceride(triacylglycerol[TAG])synthesis,cell proliferation,and cell adhesion.RNA sequencing detected a set of genes that were upregulated in the 8-d late pupal fat body at a late metamorphic stage compared with the 2-d pupal fat body at an earlier metamorphic stage.The pathways for glycolysis,TAG synthesis,cell proliferation,and cell adhesion were enriched by the differentially expressed genes,and the key genes linked with these pathways showed increased expression in the 8-d pupal fat body.Knockdown of phosphofructokinase(Pfk),acetyl-CoA carboxylase(Acc1),phosphatidylinositol 4,5-bisphosphate 3-kinase catalytic subunit(P110)and collagen alpha-1(IV)chain(Col4a1)by RNA interference resulted in abnormal eclosion and death at pupal stages,and repressed lipid droplets accumulation and adult fat body development.The expression of Acc1,P110,and Col4a1 was repressed by the insect steroid hormone 20-hydroxyecdysone(20E).The critical genes in the 20E pathway appeared to decrease at the late pupal stage.These data suggested that the development of the insect adult fat body is regulated by glycolysis,lipids synthesis,cell proliferation,and cell adhesion at the late pupal stage when the 20E signal decreases.
基金Open Access funding enabled and organized by Projekt DEALfinancially supported by H. Wilhelm Schaumann foundation。
文摘Background In contrast to protein-rich insect meal,the feed potential of insect fat is generally less explored and knowledge about the suitability of insect fat as a fat source specifically in broiler diets is still limited.In view of this,the present study aimed to comprehensively investigate the effect of partial(50%) and complete replacement of soybean oil with insect fat from Hermetia illucens(HI) larvae in broiler diets on performance,fat digestibility,cecal microbiome,liver transcriptome and liver and plasma lipidomes.Thus,100 male,1-day-old Cobb 500 broilers were randomly assigned to three groups and fed three different diets with either 0(group HI-0,n cens(HI) larvae fat for 35 d.= 30),2.5%(group HI-2.5,n %(HI-5.0,n = 35) or 5.0= 35) Hermetia illuResults Body weight gain,final body weight,feed intake,and feed:gain ratio during the whole period and apparent ileal digestibility coefficient for ether extract were not different between groups.Cecal microbial diversity did not differ between groups and taxonomic analysis revealed differences in the abundance of only four low-abundance bacterial taxa among groups;the abundances of phylum Actinobacteriota,class Coriobacteriia,order Coriobacteriales and family Eggerthellaceae were lower in group HI-5.0 compared to group HI-2.5(P < 0.05).Concentrations of total and individual short-chain fatty acids in the cecal digesta were not different between the three groups.Liver transcriptomics revealed a total of 55 and 25 transcripts to be differentially expressed between groups HI-5.0 vs.HI-0 and groups HI-2.5 vs.HI-0,respectively(P < 0.05).The concentrations of most lipid classes,with the exception of phosphatidylethanolamine,phosphatidylglycerol and lysophosphatidylcholine in the liver and cholesterylester and ceramide in plasma(P < 0.05),and of the sum of all lipid classes were not different between groups.Conclusions Partial and complete replacement of soybean oil with HI larvae fat in broiler diets had no effect on growth performance and only modest,but no adverse effects on the cecal microbiome and the metabolic health of broilers.This suggests that HI larvae fat can be used as an alternative fat source in broiler diets,thereby,making broiler production more sustainable.
