The effect of fat mass and obesity associated proteins mediated mRNA m6A modification on animal fat deposition and its application prospects / 生物工程学报

In the process of animal fat deposition, the proliferation and differentiation of pre-adipocytes and the change of lipid droplet content in adipocytes are regulated by a series of transcription factors and signal pathways. Although researchers have conducted in-depth studies on the transcriptional regulation mechanisms of adipogenesis, there are relatively few reports on post-transcriptional modification on mRNA levels. The modification of mRNA m6A regulated by methyltransferase, demethylase and methylation reading protein is a dynamic and reversible process, which is closely related to fat deposition in animals. Fat mass and obesity associated proteins (FTO) act as RNA demethylases that affect the expression of modified genes and play a key role in fat deposition. This article summarized the mechanism of FTO-mediated demethylation of mRNA m6A in the process of animal fat deposition, suggesting that FTO may become a target for effective treatment of obesity. Moreover, this review summarized the development of FTO inhibitors in recent years.

C/EBPb converts bovine fibroblasts to adipocytes without hormone cocktail induction

BACKGROUND: Adipogenesis and fibrogenesis can be considered as a competitive process in muscle, which may affect the intramuscular fat deposition. The CCAAT/enhancer-binding protein beta (C/EBPb) plays an important role in adipogenesis, which is well-characterized in mice, but little known in bovine so far. RESULTS: In this study, real-time qPCR revealed that the level of C/EBPb was increased during the developmental stages of bovine and adipogenesis process of preadipocytes. Overexpression of C/EBPb promoted bovine fibroblast proliferation through mitotic clonal expansion (MCE), a necessary process for initiating adipogenesis, by significantly downregulating levels of p21 and p27 (p < 0.01). Also, the PPARc expression was inhibited during the MCE stage (p < 0.01). 31.28% of transfected fibroblasts adopted lipid-laden adipocyte morphology after 8 d. Real-time qPCR showed that C/EBPb activated the transcription of early stage adipogenesis markers C/EBPa and PPARc. Expression of ACCa, FASN, FABP4 and LPL was also significantly upregulated, while the expression of LEPR was weakened. CONCLUSIONS: It was concluded C/EBPb can convert bovine fibroblasts into adipocytes without hormone induction by initiating the MCE process and promoting adipogenic genes expression, which may provide new insights into the potential functions of C/EBPb in regulating intramuscular fat deposition in beef cattle.

Effect of dietary nutrition on tail fat deposition and evaluation of tail-related genes in fat-tailed sheep

BACKGROUND: The effects of dietary nutrition on tail fat deposition and the correlation between production performance and the Hh signaling pathway and OXCT1 were investigated in fat-tailed sheep. Tan sheep were fed different nutritional diets and the variances in tail length, width, thickness and tail weight as well as the mRNA expression of fat-related genes (C/EBPα, FAS, LPL, and HSL) were determined in the tail fat of sheep at three different growth stages based on their body weight. Furthermore, the correlations between tail phenotypes and the Hedgehog (Hh) signaling pathway components (IHH, PTCH1, SMO, and GLI1) and OXCT1 were investigated. RESULTS: C/EBPα, FAS, LPL, and HSL were expressed with differences in tail fat of sheep fed different nutritional diets at three different growth stages. The results of the two-way ANOVA showed the significant effect of nutrition, stage, and interaction on gene expression, except the between C/EBPα and growth stage. C/EBPα, FAS, and LPL were considerably correlated with the tail phenotypes. Furthermore, the results of the correlation analysis demonstrated a close relationship between the tail phenotypes and Hh signaling pathway and OXCT1. CONCLUSIONS: The present study demonstrated the gene-level role of dietary nutrition in promoting tail fat deposition and related tail fat-related genes. It provides a molecular basis by which nutritional balance and tail fat formation can be investigated and additional genes can be identified. The findings of the present study may help improve the production efficiency of fat-tailed sheep and identify crucial genes associated with tail fat deposition.

Substitution of ractopamine by safflower or coconut oil as an additive in finishing pig diets / Substituição da ractopamina por óleo de cártamo ou óleo de coco como aditivos em dietas para suínos em terminação

ABSTRACT: The objective of this study was to explore the substitution of ractopamine by coconut or safflower oil in finishing pig diets. The study included 24 crossbred barrows weighing 78.00 ± 8.76 kg distributed in a randomized block design with four treatments and six replicates composed of: basal ration (BR), BR + 10 ppm ractopamine, BR + four 1 g capsules of safflower oil, and BR + four 1 g capsules of coconut oil. Performance evaluation showed that safflower oil, ractopamine, and coconut oil supplementation had a significant effect (P < 0.05) on weight gain and feed conversion. Carcass-related variables were also affected by the treatments (P < 0.05), with fat thickness 3 (FT3) reduced by the use of safflower oil, ractopamine, and coconut oil. Rib eye area was positively affected (P < 0.05) by diet, with ractopamine, coconut oil, and safflower oil supplementation treatments showing higher values than control diet treatment. The diets also affected fatty acid profiles (P < 0.05), with decreased myristic acid content in animals supplemented with ractopamine and safflower oil and increased deposition of palmitoleic and oleic acids in animals supplemented with coconut oil and safflower oil, respectively. Results suggested that both safflower oil and coconut oil can be used as substitutes for ractopamine.

RESUMO: Objetivou-se avaliar a substituição da suplementação da ractopamina pelo uso dos óleos de coco ou cártamo nas dietas de suínos em terminação. Foram utilizados 24 suínos machos castrados mestiços com peso médio de 78,00±8,76 kg, distribuídos em um delineamento de blocos casualizados, contendo quatro tratamentos e seis repetições compostos por: Ração Basal (RB); RB + 10 ppm de ractopamina; RB + 4 cápsulas de 1 grama cada de óleo de cártamo e RB + 4 cápsulas de 1 grama cada de óleo de coco. Na avaliação do desempenho foi observado o efeito (P<0,05) da suplementação das dietas com óleo de cártamo, ractopamina e coco no ganho de peso e conversão alimentar. As variáveis relacionadas com as carcaças também foram afetadas pelos tratamentos (P<0,05), sendo a espessura de toucinho 3 (ET3) reduzida pelo uso do óleo de cártamo, ractopamina e coco. Na avaliação da área de olho de lombo foram observados efeitos positivos (P<0,05), com maiores valores para os tratamentos suplementados com ractopamina, óleo de coco e com óleo de cártamo, quando comparados com a dieta controle. As dietas também afetaram o perfil dos ácidos graxos (P<0,05) de forma positiva, com a redução do ácido míristico do toucinho nas dietas com ractopamina e óleo de cártamo e aumento na deposição dos ácidos graxos palmitoleico e oleico do lombo nas dietas suplementadas com óleo de coco e cártamo, respectivamente. Conclui-se que tanto o óleo de coco quanto o de cártamo podem ser utilizados como substitutos da ractopamina.

Role of miRNA and lncRNA in animal fat deposition-a review / 生物工程学报

MicroRNA (miRNA) is a type of highly conserved nucleotide sequence composed of 18 to 25 nucleotides, which can specifically bind to the 3'-noncoding regions of mRNA, and then play a negative regulatory role in degrading mRNA or inhibiting translation. Long non-coding RNA (lncRNA) is a type of nucleotide sequence that exceeds 200 nucleotides in length and cannot encode proteins or can only encode protein peptides. It regulates gene expression at the levels of epigenetic, transcriptional and post-transcriptional. As an important energy storage organ, fat plays an important role in regulating the energy balance of animals, and is closely related to meat production traits such as meat production and meat quality. And the disorder of fat function can lead to hyperlipidemia, type 2 diabetes and a series of cardiovascular diseases, so the molecular regulation mechanism of animal fat deposition has attracted more attention. In recent years, more and more studies have found that miRNA and lncRNA play a crucial role in animal fat deposition. We review here the current research progresses in the role of miRNA and lncRNA in animal fat deposition, to provide theoretical guidance and new ideas for further revealing the molecular regulation mechanism of animal fat deposition.

Effects of resistant dextrin on liver fat deposition and the AMPK signaling pathway in high-fat diet-fed mice / 中华内分泌代谢杂志

Objective@#To study the effects of resistant dextrin (RD) on liver fat deposition in high-fat diet-fed (HFD) mice, and to further explore whether it can regulate the AMPK signaling pathway.@*Methods@#Thirty-six 4-week-old male C57BL/6 mice were randomly divided into three groups: normal control group (chow), high-fat diet group (HFD), and high-fat diet+ resistant dextrin group (HFD+ RD, 10 g·kg-1·d-1). After 12 weeks of intervention, the liver tissues and serum samples were collected. Serum triglyceride (TG), total cholesterol (TC), low-density lipoprotein-cholesterol (LDL-C), high-density lipoprotein-cholesterol (HDL-C), aspartate aminotransferase (AST), alanine transaminase (ALT) levels and liver TG were measured. Liver tissue HE and oil red O staining were performed to observe hepatocyte steatosis and liver fat deposition. Quantitative real-time PCR was performed to detect the relative expression of fatty acid synthesis related genes SREBP1, ACC, SCD1 in the liver tissue, and Western blot was performed to detect relative protein levels of pAMPK, SREBP1, Fasn, and ACC in the liver.@*Results@#Compared with chow group, the body weight gain, fasting blood glucose (FBG), serum TC, LDL-C, HDL-C, and ALT levels were increased in HFD group (P<0.01), and serum AST level was also increased (P<0.05). Moreover, liver oil red O staining revealed that liver fat deposition was much more obvious in HFD group than that in chow group, and liver TG was also increased in HFD group (P<0.01). The mRNA levels of SREBP1 and ACC were increased in HFD group compared with that in chow group, and the protein level of pAMPK was reduced in HFD group (P<0.05). As compared with HFD group, the body weight gain, serum TG, TC, LDL-C, HDL-C and ALT levels were significantly reduced in RD group (P<0.01), and FBG level was also reduced (P<0.05). Moreover, RD treatment alleviated liver fat deposition and TG accumulation (P<0.01). The mRNA levels of SREBP1, ACC, and SCD1 were all reduced in RD group compared with HFD group. The protein level of pAMPK was increased, and the expression of Fasn was reduced with RD treatment (P<0.01).@*Conclusion@#Resistant dextrin improves liver fat deposition and activates the AMPK signaling pathway in HFD-fed mice.

Ultrasonic estimation on pancreatic fat deposition and its relationship with risk factor for diabetes / 中华胰腺病杂志

Objective To investigate the feasibility of evaluating the pancreatic fat deposition with ultrasound,and analyze the relationship of pancreatic fat deposition with the risk factors for diabetes.Methods Two hundred and ninety-four subjects were recruited in the diabetes epidemic survey of Shanghai Sixth Peoples' Hospital,Shanghai Jiaotong University from Oct 2015 to Jan 2016,including 111 diabetes mellitus (DM) cases,54 sugar metabolic abnormalities (IGR) cases,and 129 healthy cases as control group.The general data were collected.Biochemical indicators including ALT,AST and insulin in fasting blood samples were detected,and insulin resistance index (HOMA2-IR) and insulin secretion index (HOMA-IS) were calculated.The pancreatic fat deposition was evaluated by the ultrasound,and pancreas echoes were divided into three levels (1,2,3),by comparing with the echo of the rectus.The Chi-square test was used to analyze the pancreatic fat deposition rate,while the Logistic regression was used to figure out the diabetes high-risk factors influencing the pancreatic fat deposition.Results Forty-two subjects were found to have the pancreatic fat deposition in the healthy group (33.3％),of whom 19 cases,16 cases and 8 cases were categorized into level 1,2 and 3,respectively.Thirty subjects were found to have the pancreatic fat deposition in the IGR group (55.6％),of whom 14 cases,11 cases and 5 cases were categorized into level 1,2 and 3,respectively.Sixty-seven subjects were found to have the pancreatic fat deposition in the DM group (60.4％),of whom 37 cases,18 cases and 12 cases,were categorized into level 1,2,3,respectively.The pancreatic fat deposition rates of the 3 groups were statistically significantly different (P＜0.01).Multivariate Logistic regression analysis showed that body mass index (BMI),HOMA2-IR,high triglycerides (TG),and total cholesterol (TC) may be the-risk factors for the pancreatic fat deposition in IGR and T2DM patients.Conclusions The ultrasound evaluation on pancreatic fat deposition was feasible,and the pancreatic fat deposition was related to multiple high-risk factors for diabetes.

Consumo alimentar residual e sua relação com medidas de desempenho e eficiência e características in vivo da carcaça de cordeiros / The residual feed intake and its relationship with performance and efficiency measures and in vivo carcass characteristics of lambs

Avaliou-se o consumo alimentar residual (CAR) e a conversão alimentar (CA) de 20 cordeiros, com o objetivo de estimar as correlações entre essas variáveis com medidas de desempenho e com características in vivo da carcaça. Os animais tiveram o consumo de MS (CMS) mensurado por 65 dias e foram pesados a cada 13 dias para obtenção do ganho médio diário (GMD). Foram considerados o peso vivo inicial (PVI), o peso vivo final (PVF), o peso metabólico (PM), o GMD, a taxa de crescimento relativo (TCR), a taxa de Kleiber (TK), a CA, o CMS e o CMS em percentual do PV (CMSPV). As avaliações de carcaça foram realizadas por ultrassom. O CAR se mostrou correlacionado com o CMS (+0,81), o CMSPV (+0,90) e a CA (+0,63). Correlações significativas foram encontradas entre CA e GMD; CA e TCR; CA e TK; e CA e PVI (-0,63, -0,74, -0,75 e +0,51, respectivamente). O CAR e a CA não se mostraram correlacionados com características de carcaça, e, da mesma forma, não houve diferença entre as classes de CAR para essas variáveis. Confirmou-se o potencial do CAR como medida de eficiência alimentar para cordeiros em confinamento, sem existência de relações com o ganho de peso e o tamanho corporal e sem alterações na composição da carcaça.

The residual feed intake (RFI) and the feed conversion ratio (FCR) of 20 lambs was evaluated in order to estimate the correlations between these traits and performance measures and with in vivo carcass characteristics. The animals had their dry matter intake (DMI) measured over 65 days and they were weighed every 13 days to determine the average daily weight gain (ADG). Initial body weight (IBW), final body weight (FBW), metabolic weight (MW), ADG, relative growth rate (RGR), Kleiber ratio (KR), FCR, DMI and DMI in BW percentual (BWDMI) were considered. The carcass evaluation was performed by ultrasound. The RFI was correlated with the DMI (+0.81), BWDMI (+0.90) and with FCR (+0.63). Significant correlations were found between FCR and ADG; FCR and RGR; and FCR and KR; and FCR and IBW (-0.63, -0.74, -0.75 and +0.51 respectively). The RFI and the FCR were not correlated with carcass traits and similarly there was no difference between the RFI-classes for these variables. It was proved the RFI has potential as a measure of feed efficiency for housed lambs, without the existence of relations with weight gain and body size of animals and without changes in carcass composition.

Lisina digestível para frangos de corte machos entre 12 e 22 dias de idade / Digestible lysine for male broilers from 12 to 22 days of age

Avaliou-se nível de lisina digestível para 1050 frangos de corte dos 12 aos 22 dias de idade. O delineamento experimental foi inteiramente ao acaso, com cinco tratamentos, sete repetições e 30 aves por unidade experimental. Os tratamentos foram: 1,05; 1,10; 1,15; 1,20 e 1,25 por cento de lisina digestível. Avaliaram-se ganho de peso, consumo de ração, conversão alimentar, composição e deposição de nutrientes corporais. Foram constatados efeitos quadráticos de lisina digestível no consumo de ração e resposta linear ascendente no peso da carcaça. Na composição química da carcaça, houve resposta quadrática do nível de lisina na concentração de proteína. As taxas de deposição proteica, deposição de água, da carcaça e do corpo total tiveram aumento linear em resposta ao acréscimo de lisina na dieta. O aumento da concentração de lisina, todavia, coincidiu com a redução da matéria mineral nas vísceras e sangue e no corpo total. Considerado o desempenho, o nível 1,1 por cento de lisina digestível atendeu às necessidades do frango de corte entre o 12º e o 22º dia de idade. Consideradas a composição química e as taxas de deposição dos nutrientes corporais, a demanda pelo aminoácido digestível torna-se igual ou maior que 1,25 por cento.

The lysine level was evaluated for 1,050 male broilers from 12 to 22 days of age. The experimental design was completely randomized with five treatments, seven replications, and 30 birds per experimental unit. The treatments were: 1.05, 1.10, 1.15, 1.20, and 1.25 percent of digestible lysine. Weight gain, feed intake, feed: gain ratio, body composition, and nutrient deposition were measured. There were quadratic effects of digestible lysine on feed intake and an ascendant linear effect on carcass weight. In the carcass chemical composition, there was a quadratic response of lysine level in protein concentration. The deposition rates in carcass protein, carcass water, and whole body had a linear increase as response to lysine addition to diet. The lysine level increase however coincided with the mineral decrease on blood, offal, and whole body. Basing on performance, the digestible lysine 1.1 percent level attended the broiler needs from 12 to 22 days of age. On the other hand, considering the chemical composition and the nutrient accretion rates, the need for digestible amino acid was equal or higher than 1.25 percent.

Teores de proteína bruta em dietas práticas para juvenis de carpa capim / Crude protein levels in practical diets for grass carp juveniles

Avaliou-se a resposta de juvenis de carpa capim (Ctenopharyngodon idella) à inclusão de proteína bruta (PB) em dietas práticas, em um experimento com 120 juvenis e 80 dias de duração. As dietas eram compostas por farinha de carne suína, farelo de soja, milho e farelo de trigo com 22, 30, 36 ou 44 por cento de PB. Dez juvenis (153,0±1,5g) por tanque (850L) foram alimentados duas vezes ao dia (3 por cento da biomassa). Foi observado efeito linear positivo da PB para peso final, ganho em peso, taxa de crescimento específico, rendimento de carcaça e filé, coeficiente de retenção proteica, taxa de eficiência proteica, deposição de gordura e proteína e hematócrito. O mesmo efeito também foi observado para triglicerídeos e colesterol total no sangue, indicando que a proteína da dieta foi utilizada como fonte energética. Conversão alimentar aparente e gordura no peixe inteiro apresentaram efeito quadrático, com pontos de máxima em 40,6 e 37,1 por cento de PB, respectivamente. Pode-se concluir que a porcentagem mínima de PB para a carpa capim na fase de recria foi de 44 por cento e que a variação da proteína da dieta promoveu alterações no metabolismo dos juvenis de carpa capim, refletidos nos parâmetros sanguíneos e de carcaça.

The response of grass carp (Ctenopharyngodon idella) juveniles to crude protein (CP) levels in practical diets was evaluated in an experiment with 120 juveniles and 80 days of feeding. The diets containing porcine meat meal, soybean meal, corn and wheat meal, with 22, 30, 36, or 44 percent CP. Ten juveniles (153.0±1.5 g) per tank (850L) were fed twice daily with pelleted feed (3 percent of biomass). Linear effect of CP on final weight, weight gain, specific growth rate, carcass and fillet yield, coefficient of protein retention, protein efficiency rate, deposition of fat and protein, and hematocrit were observed. It was also observed effect on triglycerides and total cholesterol in blood, indicating that dietary protein was being used as energy source. Feed conversion ratio and fat content in whole fish showed quadratic effect, with maximum points at 40.6 and 37.1 percent CP, respectively. The best CP content for grass carp in growing phase was 44 percent, and the variation of protein content in diet changed the metabolism of grass carp juveniles, reflected in blood and carcass parameters.

Bovine gene polymorphisms related to fat deposition and meat tenderness

Leptin, thyroglobulin and diacylglycerol O-acyltransferase play important roles in fat metabolism. Fat deposition has an influence on meat quality and consumers' choice. The aim of this study was to determine allele and genotype frequencies of polymorphisms of the bovine genes, which encode leptin (LEP), thyroglobulin (TG) and diacylglycerol O-acyltransferase (DGAT1). A further objective was to establish the effects of these polymorphisms on meat characteristics. We genotyped 147 animals belonging to the Nelore (Bos indicus), Canchim (5/8 Bos taurus + 3/8 Bos indicus), Rubia Gallega X Nelore (1/2 Bos taurus + 1/2 Bos indicus), Brangus Three-way cross (9/16 Bos taurus + 7/16 Bos indicus) and Braunvieh Three-way cross (3/4 Bos taurus + 1/4 Bos indicus) breeds. Backfat thickness, total lipids, marbling score, ribeye area and shear force were fitted, using the General Linear Model (GLM) procedure of the SAS software. The least square means of genotypes and genetic groups were compared using Tukey's test. Allele frequencies vary among the genetic groups, depending on Bos indicus versus Bos taurus influence. The LEP polymorphism segregates in pure Bos indicus Nelore animals, which is a new finding. The T allele of TG is fixed in Nelore, and DGAT1 segregates in all groups, but the frequency of allele A is lower in Nelore animals. The results showed no association between the genotypes and traits studied, but a genetic group effect on these traits was found. So, the genetic background remains relevant for fat deposition and meat tenderness, but the gene markers developed for Bos taurus may be insufficient for Bos indicus.

Environmental and hormonal control of vernal migration in redheaded bunting (Emberiza bruniceps).

This paper reviews the factors and mechanisms which result in the development of the metabolic state characteristic of migration with special reference to a palaeotropic migrant the redheaded bunting, Emberiza bruniceps. Changes in climatic conditions and food supply act as proximate triggers of migratory behaviour in partial migrants. Typical migrants like buntings use daylength as a cue but the exact mechanism of how photoperiodic information is translated in terms of migratory events is still not known. Almost entirely the photoperiodic effects have been explained on the basis of the involvement of hypothalamo/hypophyseal system. We feel mechanism(s) other than those acting through neuroendocrine system may be equally important. Furthermore the role of temperature has not been adequately explored so far. Our observations indicate the possibility that redheaded buntings might integrate the information received from photoperiod with environmental temperature (and other factors?) resulting in the development of migratory state. The physiological control of avian migration is much less understood. Majority of papers have centered around the ‘gonadal hypothesis’ of Rowan supporting or contradicting it without providing conclusive evidence. Pituitary prolactin has also been shown to be implicated although the mechanism of action is only speculative. Conclusive evidence for the involvement of thyroid hormones (thyroxine, T4; triiodothyronine, T3) in the physiological timing of migration has been produced attributing independent roles to T4 and T3. It is suggested that seasonal variation in peripheral conversion of T4 to T3 could serve as an effective strategy to render available the required thyroid hormones T4 and/or T3 during different phases of the year thus accounting for the metabolic switch over from T4-dependent moult to T3-dependent migratory fat deposition and zugunruhe and also ensuring preclusion of simultaneous occurrence of these mutually incompatible events. Considering that the number of environmental and physiological factors influence this mechanism and considering that thyroid hormone molecule has been put to a wide range of usage during the course of evolution the mechanism(s) of peripheral conversion of T4-T3 may assume great flexibility and have selective value-especially in migration which is known to have evolved several times in diverse avian families. The attractiveness of this hypothesis lies in the fact that it has potential to explain the both physiological development of the metabolic state of migration and at the same time the physiological timing of migration not only with respect to the cycle of environment but also with respect to other conflicting seasonal events (moult and reproduction).