Transcriptome analysis reveals steroid hormones biosynthesis pathway involved in abdominal fat deposition in broilers

Excessive abdominal fat deposition reduces the feed efficiency and increase the cost of production in broilers.Therefore,it is an important task for poultry breeders to breed broilers with low abdominal fat.Abdominal fat deposition is a highly complex biological process,and its molecular basis remains elusive.In this study,we performed transcriptome analysis to compare gene expression profiles at different stages of abdominal fat deposition to identify the key genes and pathways involved in abdominal fat accumulation.We found that abdominal fat weight(AFW)increased gradually from day 35(D35)to 91(D91),and then decreased at day 119(D119).Accordingly,after detecting differentially expressed genes(DEGs)by comparing gene expression profiles at D35 vs.D63 and D35 vs.D91,and identifying gene modules associated with fat deposition by weighted gene co-expression network analysis(WGCNA),we performed intersection analysis of the detected DEGs and WGCNA gene modules and identified 394 and 435 intersecting genes,respectively.The results of the Gene Ontology(GO)functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway enrichment analyses showed that the steroid hormone biosynthesis and insulin signaling pathways were co-enriched in all intersecting genes,steroid hormones have been shown that regulated insulin signaling pathway,indicating the importance of the steroid hormone biosynthesis pathway in the development of broiler abdominal fat.We then identified 6 hub genes(ACTB,SOX9,RHOBTB2,PDLIM3,NEDD9,and DOCK4)related to abdominal fat deposition.Further analysis also revealed that there were direct interactions between 6 hub genes.SOX9 has been shown to bind to proteins required for steroid hormone receptor binding,and RHOBTB2 indirectly regulates the steroid hormones biosynthesis through cyclin factor,and ultimately affect fat deposition.Our results suggest that the genes RHOBTB2 and SOX9 play an important role in fat deposition in broilers,by regulating steroid hormone synthesis.These findings provide new targets and directions for further studies on the mechanisms of fat deposition in chicken.

Correlation between type 2 diabetes mellitus remission and intrapancreatic fat deposition

BACKGROUND Intrapancreatic fat deposition(IPFD)exerts a significant negative impact on patients with type 2 diabetes mellitus(T2DM),accelerates disease deterioration,and may lead to impairedβ-cell quality and function.AIM To investigate the correlation between T2DM remission and IPFD.METHODS We enrolled 80 abdominally obese patients with T2DM admitted to our institution from January 2019 to October 2023,including 40 patients with weight lossinduced T2DM remission(research group)and 40 patients with short-term intensive insulin therapy-induced T2DM remission(control group).We comparatively analyzed improvements in IPFD[differential computed tomography(CT)values of the spleen and pancreas and average CT value of the pancreas];levels of fasting blood glucose(FBG),2-h postprandial blood glucose(2hPBG),and insulin;and homeostasis model assessment of insulin resistance(HOMA-IR)scores.Correlation analysis was performed to explore the association between T2DM remission and IPFD.RESULTS After treatment,the differential CT values of the spleen and pancreas,FBG,2hPBG,and HOMA-IR in the research group were significantly lower than those before treatment and in the control group,and the average CT value of the pancreas and insulin levels were significantly higher.Correlation analysis revealed that the greater the T2DM remission,the lower the amount of IPFD.

Identification and characterization of genes that control fat deposition in chickens

Background： Fat deposits in chickens contribute significantly to meat quality attributes such as juiciness, flavor, taste and other organoleptic properties. The quantity of fat deposited increases faster and earlier in the fast- growing chickens than in slow-growing chickens. In this study, Affymetrix Genechip~ Chicken Genome Arrays 32773 transcripts were used to compare gene expression profiles in liver and hypothalamus tissues of fast-growing and slow-growing chicken at 8 wk of age. Real-time RT-PCR was used to validate the differential expression of genes selected from the microarray analysis. The mRNA expression of the genes was further examined in fat tissues. The association of single nucleotide polymorphisms of four lipid-related genes with fat traits was examined in a F2 resource population. Results： Four hundred genes in the liver tissues and 220 genes hypothalamus tissues, respectively, were identified to be differentially expressed in fast-growing chickens and slow-growing chickens. Expression levels of genes for lipid metabolism （SULTIB1, ACSBG2, PNPLA3, LPL, AOAH） carbohydrate metabolism （MGAT4B, XYLB, GBE1, PGM1, HKDCl）cholesttrol biosynthesis （FDPS, LSS, HMGCR, NSDHL, DHCR24, IDI1, MEI） HSD17B7 and other reaction or pro- cesses （CYPIA4, CYP1A1, AKR1BI, CYP4V2, DDO） were higher in the fast-growing White Recessive Rock chickens than in the slow-growing Xinghua chickens. On the other hand, expression levels of genes associated with multicellular organism development, immune response, DNA integration, melanin biosynthetic process, muscle organ develop- ment and oxidation-reduction （FRZB, DMD, FUT8, CYP2C45, DHRSX, and CYP2C18） and with glycol-metabolism （GCNT2, ELOVL d, and FASN）, were higher in the XH chickens than in the fast-growing chickens, fiT-PCR validated high expression levels of nine out of 12 genes in fat tissues. The G1257069A and T1247123C of the ACSBG2 gene were significantly associated with abdominal fat weight. The G4928024A of the FASN gene were significantly associ- ated with fat bandwidth, and abdominal fat percentage. The C4930169T of the FASN gene was associated with ab- dominal fat weight while the A59539099G of the ELOVL 6 was significantly associated with subcutaneous fat. The A8378815G of the DDT was associated with fat band width. Conclusion： The differences in fat deposition were reflected with differential gene expressions in fast and slow growing chickens.

Fat deposition deficiency is critical for the high mortality of pre-weanling newborn piglets

Background: The high mortality of pre-weanling piglets is a dominant challenge which severely restricts the development of pig industry. A number of factors including nutrients imbalance and temperature variation during postnatal period of piglets have been reported to closely associated with the high mortality of postnatal piglets.This study aims to find out the relationship between fat deposition and survival of newborn piglets.Results: There were no differences in organ coefficient and bone density between the surviving and dead piglets(P > 0.05). The body weight and the fat deposition in the dead piglets were lower than the live individuals(P < 0.05).Consistently, the average sizes of white adipocytes in back and abdominal adipose tissues of dead piglets were smaller than the survivals(P < 0.05). The protein expression levels of adipocyte differentiation markers PPARγ and C/EBPα in the back and abdominal adipose tissues were lower in dead piglets compared to live piglets. The mRNA expressions of thermogenic markers PGC1α and PRDM16 in adipose tissues were decreased in the dead piglets(P < 0.05). The microarray of back fat samples from the surviving and dead piglets were conducted; two down-regulated genes namely AAMDC and CASTOR1 were identified from the dead piglets. According to quantitative real-time PCR(RT-PCR) analysis, the mRNA expression of AAMDC decreased, whereas CASTOR1 expression elevated in the dead piglets compared to the surviving piglets(P < 0.05).Conclusions: The fat deposition and adipocyte differentiation in the dead piglets are insufficient compared to the surviving piglets, which may attenuate the thermogenic ability of white adipose tissue(WAT). Our data indicate that fat deposition in newborn piglets is vital to their survival.

Identification of key genes affecting porcine fat deposition based on coexpression network analysis of weighted genes

Background:Fat deposition is an important economic consideration in pig production.The amount of fat deposition in pigs seriously affects production efficiency,quality,and reproductive performance,while also affecting consumers’choice of pork.Weighted gene co-expression network analysis(WGCNA)is effective in pig genetic studies.Therefore,this study aimed to identify modules that co-express genes associated with fat deposition in pigs(Songliao black and Landrace breeds)with extreme levels of backfat(high and low)and to identify the core genes in each of these modules.Results:We used RNA sequences generated in different pig tissues to construct a gene expression matrix consisting of 12,862 genes from 36 samples.Eleven co-expression modules were identified using WGCNA and the number of genes in these modules ranged from 39 to 3,363.Four co-expression modules were significantly correlated with backfat thickness.A total of 16 genes(RAD9A,IGF2R,SCAP,TCAP,SMYD1,PFKM,DGAT1,GPS2,IGF1,MAPK8,FABP,FABP5,LEPR,UCP3,APOF,and FASN)were associated with fat deposition.Conclusions:RAD9A,TCAP,SMYD1,PFKM,GPS2,and APOF were the key genes in the four modules based on the degree of gene connectivity.Combining these results with those from differential gene analysis,SMYD1 and PFKM were proposed as strong candidate genes for body size traits.This study explored the key genes that regulate porcine fat deposition and lays the foundation for further research into the molecular regulatory mechanisms underlying porcine fat deposition.

Dietary methionine deficiency stunts growth and increases fat deposition via suppression of fatty acids transportation and hepatic catabolism in Pekin ducks

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.

A 314-bp SINE insertion in the ZNF2 promoter region may act as a repressor related to regulation of fat deposition in pigs

Retrotransposons,a type of DNA fragment that can mobilize itself on genome,can generate genetic variations and develop for molecular markers based on the insertion polymorphism.Zinc finger proteins(ZNFs)are among the most abundant proteins in eukaryotic animals,and their functions are extraordinarily diverse and particularly important in gene regulation.In the current study,bioinformatic prediction was performed to screen for retrotransposon insertion polymorphisms(RIPs)in six ZNF genes(ZNF2,ZNF3,ZNF7,ZNF8,ZNF10 and ZNF12).Six RIPs in these ZNFs,including one short interspersed nuclear element(SINE)RIP in intron 1 and one long interspersed nuclear element 1(L1)RIP in intron 3 of ZNF2,one SINE RIP in 5′flanking region and one SINE RIP in intron 2 of ZNF3,one SINE RIP in 3′UTR of ZNF7 and one L1 RIP in intron 2 of ZNF12,were discovered and their presence was confirmed by PCR.The impact of the SINE RIP in the first intron of ZNF2,which is close to the core promoter of ZNF2,on the gene activity was investigated by dual-luciferase assay in three cell lines.Our results showed that the SINE insertion in the intron 1 of ZNF2 repressed the core promoter activity extremely significantly(P<0.01)in cervical cancer cells and porcine primary embryonic fibroblasts(HeLa and PEF),thus SINE may act as a repressor.This SINE RIP also significantly(P<0.05)affected the corrected back fat thickness in Yorkshire pigs.The corrected back fat thickness of individuals with SINE insertion in the first intron of ZNF2 was significantly(P<0.05)higher than that of individuals without SINE insertion.In summary,our data suggested that RIPs play important roles in the genetic variations of these ZNF genes and SINE RIP in the intron 1 of ZNF2 may provide a useful molecular marker for the screening of fat deposition in the pig breeding.

Effects of Maternal Dietary Energy Restriction on Fat Deposition of Offspring

The study was carried out to investigate the effects of maternal dietary energy restriction on growth performance, serum indices and fat deposition of offspring. A total of 400 female Arbor Acres （AA） broiler breeders were studied. These female birds involved three experimental treatments and a control group with normal dietary energy diets （ND, 11.7 MJ of ME. kgt during the laying）. In treatments 2, 3 and 4, the energies of diets were 20%, 30% and 50% （LD20, LD30 and LD50） lower than those of the control, respectively. The study commenced at the beginning of the laying period when the total egg production reached 5% of the flock. All the broiler offspring were fed the same diets. The results showed that in low energy diets, offspring showed decreased 1-day-old weight, but 49-day-old weight was higher in LD20 diet （P〈0.05）. For offspring during days 1-49, the average daily gain （ADG） in LD20 group and the feed conversion ratio in LD50 group were improved as compared with those of the control （P〈0.05）. Compared with the control, abdominal fat percentage increased in 49-day-old offspring from LD30 diet （P〈0.05）; the fat content of breast muscle in offspring increased in broilers fed low energy diets （P〈0.05）. In 28-day-old offspring from breeders given LD20 and LD50 diets, liver fat percentages were higher compared with ND （P〈0.05）. The subcutaneous fat thickness in 28-day-old offspring from LD50 group and 49-day-old offspring from LD30 group was higher （P〈0.05）. On day 49, the serum cholesterol （CHO） of offspring from breeders fed LD20 diet and serum high-density lipoprotein （HDL） of offspring from breeders fed LD50 diet reduced compared with those of the control （P〈0.05）. In addition, a higher triiodothyronine （T3） content in serum was found in offspring from broiler breeders given LD20 and LD30 diets （P〈0.05）. Serum thyroxine （T4） in offspring significantly decreased with the decrease of diet energy （P〈0.05）. In conclusion, to a certain extent, dietary energy restriction in breeders could improve growth performance and promote lipid metabolism of offspring.

Trimethylamine oxide supplementation differentially regulates fat deposition in liver,longissimus dorsi muscle and adipose tissue of growing-finishing pigs

Trimethylamine oxide(TMAO)is a microbiota-derived metabolite,and numerous studies have shown that it could regulate fat metabolism in humans and mice.However,few studies have focused on the effects of TMAO on fat deposition in growing-finishing pigs.This study aimed to investigate the effect of TMAO on fat deposition and intestinal microbiota in growing-finishing pigs.Sixteen growing pigs were randomly divided into 2 groups and fed with a basal diet with 0 or 1 g/kg TMAO for 149 d.The intestinal microbial profiles,fat deposition indexes,and fatty acid profiles were measured.These results showed that TMAO supplementation had a tendency to decrease lean body mass(P<0.10)and significantly increased backfat thickness(P<0.05),but it did not affect growth performance.TMAO significantly increased total protein(TP)concentration,and reduced alkaline phosphatase(ALP)concentration in serum(P<0.05).TMAO increased the α diversity of the ileal microbiota community(P<0.05),and it did not affect the colonic microbial community.TMAO supplementation significantly increased acetate content in the ileum,and Proteobacteria and Escherichia-Shigella were significantly enriched in the TMAO group(P<0.05).In addition,TMAO decreased fat content,as well as the ratio of linoleic acid,n-6 polyunsaturated fatty acids(PUFA),and PUFA in the liver(P<0.05).On the contrary,TMAO increased intramuscular fat content of the longissimus dorsi muscle,whereas the C18:2n6c ratio was increased,and the n-6 PUFA:PUFA ratio was decreased(P<0.05).In vitro,1 mmol/LTMAO treatment significantly upregulated the expression of FASN and SREBP1 in C2C12 cells(P<0.05).Nevertheless,TMAO also increased adipocyte area and decreased the CPT-1B expression in subcutaneous fat(P<0.05).Taken together,TMAO supplementation regulated ileal microbial composition and acetate production,and regulated fat distribution and fatty acid composition in growing-finishing pigs.These results provide new insights for understanding the role of TMAO in humans and animals.

Association between intra-pancreatic fat deposition and diseases of the exocrine pancreas: A narrative review

Intrapancreatic fat deposition(IPFD)has garnered increasing attention in recent years.The prevalence of IPFD is relatively high and associated with factors such as obesity,age,and sex.However,the pathophysiological mechanisms underlying IPFD remain unclear,with several potential contributing factors,including oxida-tive stress,alterations in the gut microbiota,and hormonal imbalances.IPFD was found to be highly correlated with the occurrence and prognosis of exocrine pan-creatic diseases.Although imaging techniques remain the primary diagnostic approach for IPFD,an expanding array of biomarkers and clinical scoring systems have been identified for screening purposes.Currently,effective treatments for IPFD are not available;however,existing medications,such as glucagon-like peptide-1 receptor agonists,and new therapeutic approaches explored in animal models have shown considerable potential for managing this disease.This paper reviews the pathogenesis of IPFD,its association with exocrine pancreatic disea-ses,and recent advancements in its diagnosis and treatment,emphasizing the significant clinical relevance of IPFD.

Dietary bile acids supplementation decreases hepatic fat deposition with the involvement of altered gut microbiota and liver bile acids profile in broiler chickens

Background High-fat diets(HFD)are known to enhance feed conversion ratio in broiler chickens,yet they can also result in hepatic fat accumulation.Bile acids(BAs)and gut microbiota also play key roles in the formation of fatty liver.In this study,our objective was to elucidate the mechanisms through which BA supplementation reduces hepatic fat deposition in broiler chickens,with a focus on the involvement of gut microbiota and liver BA composition.Results Newly hatched broiler chickens were allocated to either a low-fat diet(LFD)or HFD,supplemented with or without BAs,and subsequently assessed their impacts on gut microbiota,hepatic lipid metabolism,and hepatic BA composition.Our findings showed that BA supplementation significantly reduced plasma and liver tissue triglyceride(TG)levels in 42-dav-old broiler chickens(P<0.05),concurrently with a significant decrease in the expression levels of fatty acid synthase(FAS)in liver tissue(P<0.05).These results suggest that BA supplementation effectively diminishes hepatic fat deposition.Under the LFD,BAs supplementation increased the BA content and ratio of Non 12-OH BAs/12-OH BAs in the liver and increased the Akkermansia abundance in cecum.Under the HFD,BA supplementation decreased the BAs and increased the relative abundances of chenodeoxycholic acid(CDCA)and cholic acid(CA)in hepatic tissue,while the relative abundances of Bacteroides were dramatically reduced and the Bifidobacterium,Escherichia,and Lactobacillus were increased in cecum.Correlation analyses showed a significant positive correlation between the Akkermansia abundance and Non 12-OH BA content under the LFD,and presented a significant negative correlation between the Bacteroides abundance and CA or CDCA content under the HFD.Conclusions The results indicate that supplementation of BAs in both LFD and HFD may ameliorate hepatic fat deposition in broiler chickens with the involvement of differentiated microbiota-bile acid profile pathways.

Dihydromyricetin improves liver fat deposition in high-fat diet-induced obese mice

It has been reported that the histone/protein deacetylase SIRT1-AMP-activated protein kinase(SIRT1-AMPK)signaling pathway may play a role in the effects of dihydromyricetin(DHM)on improving triglyceride(TG)accumulation and insulin resistance in liver cells.Therefore,we aimed to further observe the effect of DHM on liver fat deposition in high-fat diet(HFD)-induced obese mice and explore its possible mechanism.C57BL/6J mice were fed with a normal diet(ND)and HFD and were treated with or without low-dose(125 mg/kg)or high-dose(250 mg/kg)DHM for 16 weeks,respectively.During the experiment,body weight was checked every 2 weeks.After 16 weeks,the orbital vein was bled,the animals were sacrificed,and the subscapular,epididymal,and inguinal fat were collected and weighed with an electronic scale.An automatic biochemical analyzer was used to determine the levels of serum triglyceride(TG),serum total cholesterol(TC),serum high-density lipoprotein(HDL),and serum low-density lipoprotein(LDL).The livers were stained with hematoxylin-eosin staining(H&E)and Oil Red O to detect liver fat deposition.A colorimetric method was used to detect liver MDA and SOD contents.Quantitative real-time PCR(q RT-PCR)was used to detect the gene expressions of related indicators,such as interleukin-6(IL-6),interleukin-8(IL-8),tumor necrosis factor-α(TNF-α),acetyl-Co A carboxyl acetyl-Co A carboxylase(ACC),sterol regulatory element-binding protein-1c(SREBP-1),fatty acid synthetase(FAS),peroxisome proliferator activation receptor alpha(peroxisome proliferator-activated receptor-alpha,PPARα),palmitoyltransferase 1(carnitine palmitoyltransferase 1,CPT1),SIRT1,and AMPK.Western blotting analysis was used to detect the protein expression levels of SIRT1,AMPK,SIRT1-AMPK,ACC,SREBP-1,FAS,PPARα,and CPT1.Results showed that compared with the ND group,the weight and body fat of the mice in the HFD group were increased significantly.The levels of TG,TC,and LDL were increased,the level of HDL was decreased,the volume of hepatocytes was increased,the number of lipid droplets,fat deposition,MDA,IL-6,IL-8,TNF-α,SREBP-1c,FAS,ACC1,SIRT1,and AMPK protein levels were significantly increased,and the SOD activity,PPARα,CPT1,SIRT1 m RNA,AMPK m RNA,PPARα,CPT1 levels were significantly decreased.DHM could significantly reverse the changes of the above indexes in HFD mice,while DHM had no significant effect on the above indexes in ND mice.Collectively,our findings revealed that DHM improved liver fat deposition in HFD-induced obese mice,and the mechanism might be related to inhibition of oxidative stress,inflammation,lipid synthesis,and promotion of lipid decomposition.

FAT/CD36融合蛋白的表达及其对鸡腹脂沉积的特异性调控

【目的】脂肪酸转位酶(fatty acid translocase,FAT/CD36)是介导脂肪酸跨膜转运和脂肪细胞聚脂的重要载体蛋白。本试验采用主动免疫法研究FAT/CD36在鸡脂肪沉积调控中的作用。【方法】将FAT/CD36膜外区抗原表位基因片段克隆入表达载体pET-32a(+),并转化在大肠杆菌BL21(DE3),构建FAT/CD36融合蛋白表达载体。主动免疫试验选取22日龄黄羽肉鸡60只,按公、母各随机分为2组,共4组。公鸡和母鸡的试验组分别在第34、49、和63天肌肉注射1mg重组鸡FAT/CD36融合蛋白,以牛血清白蛋白(bovineserumalbumin,BSA)为对照。【结果】重组菌表达分子量约为29kD的鸡FAT/CD36融合蛋白,在0.1mmol·L-1IPTG诱导6h后,目的蛋白表达量占菌体总蛋白的32%。表达产物主要以包涵体的形式存在,经纯化并透析复性后得到高纯度的FAT/CD36融合蛋白。主动免疫后,公鸡和母鸡试验组的血清抗FAT/CD36抗体水平逐渐升高,并在首次免疫后显著高于各自对照组。主动免疫FAT/CD36能特异性降低公鸡的腹脂率,但对母鸡无显著性影响。试验组与对照组皮下脂肪厚度差异不显著。【结论】FAT/CD36对鸡脂肪调控具有典型的性别特异性和部位差异。试验结果为进一步阐明禽类脂肪组织特异性沉积的分子机制提供理论依据。

Molecular cloning and ontogenesis expression of fatty acid transport protein-1 in yellow-feathered broilers

Fatty acid transport protein-1 （FATP-1） is one of the important transporter proteins involved in fatty acid transmembrane transport and fat deposition. To study the relationship between FATP-1 mRNA expression and fat deposition, chicken （Gallus gallus） FATP-1 sequence was first cloned by rapid amplification of cDNA ends （RACE）. Tissue samples of chest muscle, leg muscle, subcutaneous fat, and abdominal fat were collected from six male and six female broilers each, at 22 days, 29 days, and 42 days, respectively. The tissue specificity and ontogenesis expression pattern of the FATP-1 mRNA of yellow-feathered broilers was studied by real-time reverse transcription polymerase chain reaction （RT-PCR）, and the fat deposition laws in different tissues were also compared. A 2,488 bp cDNA sequence of chicken FATP-1 was cloned by RACE （GenBank accession no. DQ352834）, including 547 bp 3＇ end untranslated region （URT） and 1,941 bp open reading frame （ORF）. Chicken FATP-1 encoded 646 amino acid residues, which shared 83.9% and 83.0% identity with those of human and rat, respectively. The results of quantitative PCR demonstrated a constant FATP-1 mRNA expression level in the chest muscle and subcutaneous fat of both male and female broilers at three stages, whereas the expression level of the FATP-1 mRNA in the leg muscle at 42 days was significantly higher than that at 22 days or 29 days. In the abdominal fat of male broilers, the gene expression significantly increased with age, whereas the female broilers showed a dramatic downregulation of FATP-1 expression in abdominal fat at 42 days. This suggested a typical tissue-and gender-specific expression pattern of chicken FATP-1, mediating the specific process of fatty acid transport or utilization in muscle and adipose tissues.

The regulation of IMF deposition in pectoralis major of fast-and slow-growing chickens at hatching

Background： The lipid from egg yolk is largely consumed in supplying the energy for embryonic growth until hatching. The remaining lipid in the yolk sac is transported into the hatchling＇s tissues. The gene expression profiles of fast-and slow-growing chickens, Arbor Acres（AA） and Beijing-You（BJY）, were determined to identify global differentially expressed genes and enriched pathways related to lipid metabolism in the pectoralis major at hatching.Results： Between these two breeds, the absolute and weight-specific amounts of total yolk energy（TYE） and intramuscular fat（IMF） content in pectoralis major of fast-growing chickens were significantly higher（P 〈 0.01,P 〈 0.01, P 〈 0.05, respectively） than those of the slow-growing breed. IMF content and u-TYE were significantly related（r = 0.9047, P 〈 0.01）. Microarray analysis revealed that gene transcripts related to lipogenesis, including PPARG, RBP7, LPL, FABP4, THRSP, ACACA, ACSS1, DGAT2, and GK, were significantly more abundant in breast muscle of fast-growing chickens than in slow-growing chickens. Conversely, the abundance of transcripts of genes involved in fatty acid degradation and glycometabolism, including ACAT1, ACOX2, ACOX3, CPT1 A, CPT2, DAK, APOO, FUT9, GCNT1,and B4 GALT3, was significantly lower in fast-growing chickens. The results further indicated that the PPAR signaling pathway was directly involved in fat deposition in pectoralis major, and other upstream pathways（Hedgehog, TGFbeta, and cytokine–cytokine receptor interaction signaling pathways） play roles in its regulation of the expression of related genes.Conclusions： Additional energy from the yolk sac is transported and deposited as IMF in the pectoralis major of chickens at hatching. Genes and pathways related to lipid metabolism（such as PPAR, Hedgehog, TGF-beta, and cytokine–cytokine receptor interaction signaling pathways） promote the deposition of IMF in the pectoralis major of fast-growing chickens compared with those that grow more slowly. These findings provide new insights into the molecular mechanisms underlying lipid metabolism and deposition in hatchling chickens.

武定鸡APOB、ADFP、FATP1基因表达量变化及其与脂肪沉积的相关性

采用荧光定量PCR技术,联合分析了不同日龄(28、49、70、91和112日龄)武定鸡载脂蛋白B基因(APOB)、脂肪酸转运蛋白1基因(FATP1)和脂肪分化相关蛋白基因(ADFP)在皮脂、腹脂、肝脏、胸肌等组织中的表达量变化,及其与活重、皮脂厚、冠重等脂肪性状形成的相关性。结果显示,ADFP基因在腹脂49日龄时的表达量显著低于28、70、91和112日龄(P<0.05),及该基因在112日龄时胸肌中的表达量显著高于皮脂、腹脂和肝脏(P<0.05);FATP1基因在28日龄时胸肌中的相对表达量显著高于皮脂、腹脂和肝脏(P<0.05);APOB基因在肝脏49日龄时的表达量显著高于28、70和91日龄(P<0.05),并且该基因在49、70、91和112日龄时肝脏中的表达量显著高于皮脂、腹脂和胸肌(P<0.05)。ADFP基因和APOB基因在皮脂中的表达存在显著相关(P<0.05),ADFP基因和FATP1基因在肝脏中的表达存在显著相关(P<0.05),推断这三个脂肪沉积相关基因可能在武定鸡脂肪性状的形成过程中具有协同调控作用。

The Comparison of the Effect of Oat and Shiitake Mushroom Powder to Prevent Body Weight Gain in Rats Fed High Fat Diet

Preventing obesity could be done by lowering plasma TAG that inhibits adipogenesis. Oat and mushroom beta-glucans in the diet has been reported to lower plasma lipid;however the data focusing on their effects on TAG and obesity are insufficient. In the present study, lowering plasma triacylglycerol, fat deposition, body weight gain (BWG) in rats fed a high fat diet (HFD) was evaluated. Rats in the control group were given HFD only and rats in the treatment group fed HFD enriched with 0.2%, 0.6% and 1.8% (wt:wt) beta-glucan from oats (LD-O, MD-O, HD-O) or mushroom (LD-M, MD-M, HD-M). After 6 weeks dietary intervention, the rats fed HD-M showed significantly lower plasma TAG, total fat mass, white adipose tissue, inguinal fat and BWG level more than HD-O treated rats (p < 0.05). The underlying mechanism in lowering plasma TAG, fat pad masses and BWG in HD-M was increasing ratio of fat faecal to faecal weight which was significantly higher than HD-O (p < 0.05). This study demonstrated that the preventing obesity via lowering plasma TAG and fat deposition was different depending on beta-glucan origin, either from oats and Shiitake mushroom.

脂肪酸受体GPR119在动物脂代谢调控中的作用研究进展

中国是水产养殖大国,而高脂饲料的广泛使用导致了鱼类脂肪代谢异常,这严重制约了水产养殖业的发展,亟待对此问题寻求解决方案。近年来在哺乳动物中的研究表明,脂代谢紊乱诱导的非酒精性脂肪肝病(Non-alcoholic fatty liver disease, NAFLD)是危害动物健康的主要问题之一,而GPR119被认为是治疗NAFLD的新靶点。GPR119在鱼类中的研究相对较少,大部分鱼类GPR119功能相关研究主要聚焦于其在调控鱼类食欲中的作用,而其在调控鱼类脂肪代谢中的作用尚不清楚。本文总结了动物中GPR119基因的结构功能及其对脂肪代谢调控机制的研究现状,旨在为研究GPR119在鱼类脂肪代谢中的作用提供新思路,为探索缓解鱼类脂代谢紊乱的新型策略提供理论参考。

鸡不同组织及细胞中gga-miR-103-3p的表达分析及其关键靶基因筛选

为初步阐明gga-miR-103-3p对鸡脂肪沉积和肌肉发育的调控作用,采用荧光定量PCR(qPCR)检测gga-miR-103-3p在S3系鸡和隐性白羽鸡(RR)腹部脂肪、肝脏、腿肌及腹部脂肪细胞、肌内脂肪细胞、成肌细胞中的表达情况,并筛选其关键靶基因。结果表明,gga-miR-103-3p在肝脏、腹部脂肪、腿肌及腹部脂肪细胞、肌内脂肪细胞、成肌细胞中均表达,并存在组织和品种(系)差异性。在肝脏中,ggamiR-103-3p在0周龄(0W)S3系鸡中的表达量显著高于RR鸡,对于S3系鸡,16周龄(16W)时gga-miR-103-3p的表达量最高,显著高于0W、2周龄(2W)、8周龄(8W)和14周龄(14W);对于RR鸡,16W和14W时gga-miR-103-3p的表达量显著高于0W和8W。在腹部脂肪中,gga-miR-103-3p在0W RR鸡中的表达量显著高于S3系鸡。2个品种(系)鸡在0W时gga-miR-103-3p的表达量均显著高于2W、8W、14W和16W,S3系鸡的表达量随着发育时期的推进而下降。在腿肌中,gga-miR-103-3p在16W时RR鸡中的表达量显著高于S3系鸡,在0W时则相反;S3系鸡中gga-miR-103-3p的表达量随着发育时期的推进总体上下降,在0W时表达量显著高于其他周龄;RR鸡中gga-miR-103-3p的表达量随着发育时期的推进呈现先下降后升高的趋势,16W时显著高于其他周龄。在腹部脂肪细胞和肌内脂肪细胞中,gga-miR-103-3p在分化4 d和分化6 d的表达量均显著高于增殖期;在成肌细胞中,gga-miR-103-3p的表达量随分化时间的延长而升高,分化5 d和分化7 d时的表达量均显著高于增殖期。gga-miR-103-3p靶基因的GO、KEGG富集及蛋白质互作分析结果表明,FBXW7、CDK6、NF1和PIK3R1是gga-miR-103-3p的重要靶基因,其中FBXW7和PIK3R1基因尤为关键。综上,gga-miR-103-3p可能是通过FBXW7、CDK6、NF1和PIK3R1影响肌肉发育、脂肪沉积,其中FBXW7和PIK3R1基因尤为关键。

影响肉牛肌内脂肪沉积的主要通路

决定大理石花纹水平的肌内脂肪含量被认为是影响牛肉嫩度、多汁性、风味和颜色等感官质量的重要因素之一。脂肪细胞的成熟须经历细胞增殖和细胞分化两个阶段。在此过程中,一些促进因子(包括PPARγ、IGF-l等)以及抑制因子(包括糖蛋白、转化生长因子β等)协同作用,通过不同通路影响肌内脂肪沉积。本文分析了脂肪生成的转录调控,阐述了信号通路在脂肪生成中的作用,以期为相关研究人员提高牛肉大理石花纹水平提供参考。