Background:Although methionine (Met), the first-limiting dietary amino acid, has crucial roles in growth and regulation of lipid metabolism in ducks, mechanisms underlying are not well understood. Therefore, the objective was to use dietary Met deficiency to investigate the involvement of Met in lipid metabolism and fat accumulation of Pekin ducks. Methods:A total of 150 male Pekin ducks (15-d-old, 558.5 ± 4.4 g) were allocated into 5 groups (6 replicates with 5 birds each) and fed corn and soybean meal-based diets containing 0.28％, 0.35％, 0.43％, 0.50％, and 0.58％Met, respectively, for 4 weeks. Met-deficient (Met-D, 0.28％Met) and Met-adequate (Met-A, 0.43％Met) groups were selected for subsequent molecular studies. Serum, liver, and abdominal fat samples were collected to assess the genes and proteins involved in lipid metabolism of Pekin ducks and hepatocytes were cultured in vivo for verification. Results:Dietary Met deficiency caused growth depression and excess fat deposition that were ameliorated by feeding diets with adequate Met. Serum triglyceride and non-esterified fatty acid concentrations increased (P< 0.05), whereas serum concentrations of total cholesterol, low density lipoprotein cholesterol, total protein, and albumin decreased (P<0.05) in Met-D ducks compared to those in Met-A ducks. Based on hepatic proteomics analyses, dietary Met deficiency suppressed expression of key proteins related to fatty acid transport, fatty acid oxidation, tricarboxylic acid cycle, glycolysis/gluconeogenesis, ketogenesis, and electron transport chain;selected key proteins had similar expression patterns verified by qRT-PCR and Western blotting, which indicated these processes were likely impaired. In vitro verification with hepatocyte models confirmed albumin expression was diminished by Met deficiency. Additionally, in abdominal fat, dietary Met deficiency increased adipocyte diameter and area (P<0.05), and down-regulated (P<0.05) of lipolytic genes and proteins, suggesting Met deficiency may suppress lipolysis in adipocyte. Conclusion:Taken together, these data demonstrated that dietary Met deficiency in Pekin ducks resulted in stunted growth and excess fat deposition, which may be related to suppression of fatty acids transportation and hepatic catabolism.

Yongbao Wu;Jing Tang;Zhiguo Wen;Bo Zhang;Junting Cao;Lulu Zhao;Zhanbao Guo;Ming Xie;Zhengkui Zhou;Shuisheng Hou

State Key Laboratory of Animal Nutrition,Key Laboratory of Animal(Poultry)Genetics Breeding and Reproduction,Ministry of Agriculture and Rural Affairs,Institute of Animal Sciences,Chinese Academy of Agricultural Sciences,Beijing 100193,China;Key Laboratory of Feed Biotechnology of Ministry of Agriculture and Rural Affairs,Institute of Feed Research,Chinese Academy of Agricultural Sciences,Beijing 100081,China

畜牧与生物技术杂志（英文版）

[1]Yongbao Wu;Jing Tang;Zhiguo Wen;Bo Zhang;Junting Cao;Lulu Zhao;Zhanbao Guo;Ming Xie;Zhengkui Zhou;Shuisheng Hou-.Dietary methionine deficiency stunts growth and increases fat deposition via suppression of fatty acids transportation and hepatic catabolism in Pekin ducks)[J].畜牧与生物技术杂志（英文版）,2022(06):1871-1886

stunts,ketogenesis,lipolytic

Dietary,methionine,deficiency,growth,increases,deposition,via,suppression,fatty,acids,transportation,hepatic,catabolism,Pekin,ducks,Background,Although,first,limiting,dietary,amino,has,crucial,roles,regulation,lipid,metabolism,mechanisms,underlying,not,well,understood,Therefore,objective,was,investigate,involvement,accumulation,Methods,total,male,old,were,allocated,into,groups,replicates,birds,each,fed,corn,soybean,meal,diets,containing,respectively,weeks,deficient,adequate,selected,subsequent,molecular,studies,Serum,liver,abdominal,samples,collected,assess,proteins,involved,hepatocytes,cultured,vivo,verification,Results,caused,depression,excess,that,ameliorated,by,feeding,triglyceride,esterified,concentrations,increased,whereas,serum,cholesterol,low,density,lipoprotein,albumin,decreased,compared,those,Based,proteomics,analyses,suppressed,expression,key,related,oxidation,tricarboxylic,cycle,glycolysis,gluconeogenesis,electron,chain,had,similar,patterns,verified,qRT,blotting,which,indicated,these,processes,likely,impaired,In,vitro,models,confirmed,diminished,Additionally,adipocyte,diameter,area,down,regulated,suggesting,may,lipolysis,Conclusion,Taken,together,data,demonstrated,resulted,stunted

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