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.

A selected population study reveals the biochemical mechanism of intramuscular fat deposition in chicken meat

Background:Increasing intramuscular fat(IMF)is an important strategy to improve meat quality,but the regulation mechanism of IMF deposition needs to be systematically clarified.Results:A total of 520 chickens from a selected line with improved IMF content and a control line were used to investigate the biochemical mechanism of IMF deposition in chickens.The results showed that the increased IMF would improve the flavor and tenderness quality of chicken meat.IMF content was mainly determined both by measuring triglyceride(TG)and phospholipid(PLIP)in muscle tissue,but only TG content was found to be decisive for IMF deposition.Furthermore,the increase in major fatty acid(FA)components in IMF is mainly derived from TGs(including C16:0,C16:1,C18:1n9c,and C18:2n6c,etc.),and the inhibition of certain very-long-chain FAs would help to IMF/TG deposition.Conclusions:Our study elucidated the underlying biochemical mechanism of IMF deposition in chicken:Prevalent accumulation of long-chain FAs and inhibitions of medium-chain FAs and very long chain FA would jointly result in the increase of TGs with the FA biosynthesis and cellular uptake ways.Our findings will guide the production of high-quality chicken meat.

Integration of association and computational methods reveals functional variants of LEPR gene for abdominal fat content in chickens

Leptin receptor(LEPR)plays a vital role in obesity in humans and animals.The objective of this study is to assess LEPR functional variants for chicken adipose deposition by integration of association and in-silico analysis using a unique chicken population,the Northeast Agricultural University broiler lines divergently selected for abdominal fat content(NEAUHLF).Five online bioinformatics tools were used to predict the functionality of the single nucleotide polymorphisms(SNPs)in coding region.Further,the possible structure–function relationship of high confidence SNPs was determined by bioinformatics analyses,including the conservation and stability analysis based on amino acid residues,prediction of protein ligand-binding sites,and the superposition of protein tertiary structure.Meanwhile,we analyzed the association between abdominal fat traits and 20 polymorphisms of chicken LEPR gene.The integrated results showed that rs731962924(N867I)and rs13684622(C1002R)could lead to striking changes in the structure and function of proteins,of which rs13684622(C1002R)was significantly associated with abdominal fat weight(AFW,P=0.0413)and abdominal fat percentage(AFP,P=0.0260)in chickens.Therefore,we are of the opinion that rs13684622(C1002R)may be an essential functional SNP affecting chicken abdominal fat deposition,and potentially applied to improvement of broiler abdominal fat in molecular marker-assisted selection(MAS)program.Additionally,the coupling of association with computer electronic predictive analysis provides a new avenue to identify important molecular markers for breeders.

The Study on Correlation Analysis of Single Nucleotide Polymorphism of IGF2 Gene and Body Fatness Traits in Chicken

Insulin-like growth factor Ⅱhas profound effects on the growth and differentiation of animal embryo. Some researches indicated that it affects the fat metabolism of poultry. This study was designed to investigate the effect of IGF2 on chicken fatness traits. Broiler, Hyline Brown layer and three native breeds (Shiqiza, Beijing You, Baier) were used in this research. Body weight and body composition traits were measured in broiler line at the age of 7 weeks. Primers for exon2 in IGF2 were designed from database of chicken genomic sequence. Polymorphisms were detected by PCR-SSCP and DNA sequencing. The total χ2 test results showed that there was a significant difference (P < 0.01) in the frequency of genotype among breeds. A C/G mutation at base position 139 was found among individuals in broiler line and the least square analysis showed that BB genotype birds had significant lower (P <0.05) abdominal fat weight and percentage of abdominal fat than AA or AB genotype birds. From the results we can conclude putatively that IGF2 gene is the major gene affecting the fatness traits of chicken or it links with the major gene, and the mutation could be used as the molecular genetic marker to select the chicken for low abdominal fat.

The Change of Plasm a very Low Density Lipoprotein Concentration Pre-or Post-Feeding and in Conrrelation with Body Fatness Traits in Broiler Chickens

Blood samples were taken from birds,from a commercial line of broiler chicken,being in a fully fed state and in fasting state for 2,4,6 hours respectively at 49 d of age and plasma very low density lipoprotein(VLDL) concentration was measured with turbidimetric assay.The experiment results showed that the variation coefficients of plasma VLDL concentration mersured at four different times were 58.11%,74.39%,69.70%,47.83%,respectively for male broilers,and 41.82%,60.87%.59.26%,50.0%for female broilers respectively.Plasma VLDL concentration decreased with the fasting time.There was a significant positive phenotypic correlation between abdominal fat weight,percentage of abdominal fat and plasma VLDL concentration for the birds being in fully feeding state,and the correlation decreased or no longer existed for the bired being in fasting state.The conclusion was that for practically application of plasma VLDL content selected in broiler chicken breeding,blood samples should be collected from birds being in feeding state.

Potential regulation of linoleic acid and volatile organic compound contents in meat of chickens by PLCD1

Omega-3(linolenic acid(ALA),docosapentaenoic acid,eicosapentaenoic acid)and omega-6(linoleic acid(LA),arachidonic acid)polyunsaturated fatty acids are essential for health and normal physiological functioning in humans.Here we report a genome-wide association study(GWAS)on LA content in chicken meat.The 19 significant single nucleotide polymorphisms(SNPs)identified by the GWAS approach were annotated in VILL,PLCD1 and OXSR1 genes with highly polymorphic linkage blocks,and explained 4.5%of the phenotypic variation in the LA content.Specifically,the PLCD1 mRNA expression level was negatively correlated with the LA content,and significantly higher in chickens with low LA content than in those with high LA content.In addition,PLCD1 was found to be involved in metabolic pathways,etc.Furthermore,the LA content was correlated with volatile organic compounds(e.g.,octanal,etc.),but no relationship was found with intramuscular fat and triglycerides in chicken meat.The results indicated that there are key SNPs in PLCD1 that regulate the content of LA,and it has no significant effect on fat deposition,but may affect the content of volatile organic compounds(VOCs).

AMPK Subunit Expression Regulates Intramuscular Fat Content and Muscle Fiber Type in Chickens

The objective of this study was to assess the role of AMPK in intramuscular fat(IMF) and fiber type in chicken muscle. The chickens were slaughtered and their muscles were collected at the ages of 4, 8, and 16 weeks so as to determine the IMF contents, as well as the expression levels of AMPK subunits, regulators of adipogenesis. In addition, the myosin heavy chains(My HCs) in thigh muscle tissues were also measured. The results showed that the IMF contents in 16-week old chickens were higher than those in 4 and 8-week-old chickens(P<0.05).The expression levels of fatty acid synthase(FAS) and fatty aicd translocase CD36(FAT/CD36) m RNA were increased significantly in samples collected at the ages of4 and 16 weeks(P<0.05). The expression levels of My HC IIa and IIb differed significantly among all the developmental stages(P <0.05). The AMPKα2, AMPKγ1,and AMPKγ3 m RNA levels were dramatically decreased with the increase of age(P <0.05). To examine the role of AMPK in adipogenesis regulation, the SV cells were cultured in an adipogenesis medium and treated with AICAR and Compound C respectively, the specific activator and inhibit of AMPK. The Compound C induced dramatically a greater expression of C/EBPβ, SREBP1 and PPARγ(P <0.05). In conclusion, the expression of AMPKα2, AMPKγ1, and AMPKγ3 m RNA is significantly correlated with the adipogenesis in skeletal muscle of chickens.

CircDOCK7 facilitates the proliferation and adipogenic differentiation of chicken abdominal preadipocytes through the gga‑miR‑301b‑3p/ACSL1 axis

Background Abdominal fat deposition depends on both the proliferation of preadipocytes and their maturation into adipocytes,which is a well-orchestrated multistep process involving many regulatory molecules.Circular RNAs(circRNAs)have emergingly been implicated in mammalian adipogenesis.However,circRNA-mediated regulation in chicken adipogenesis remains unclear.Our previous circRNA sequencing data identified a differentially expressed novel circRNA,8:27,886,180|27,889,657,during the adipogenic differentiation of chicken abdominal preadipocytes.This study aimed to investigate the regulatory role of circDOCK7 in the proliferation and adipogenic differentiation of chicken abdominal preadipocytes,and explore its molecular mechanisms of competing endogenous RNA underlying chicken adipogenesis.Results Our results showed that 8:27,886,180|27,889,657 is an exonic circRNA derived from the head-to-tail splicing of exons 19–22 of the dedicator of cytokinesis 7(DOCK7)gene,abbreviated as circDOCK7.CircDOCK7 is mainly distributed in the cytoplasm of chicken abdominal preadipocytes and is stable because of its RNase R resistance and longer half-life.CircDOCK7 is significantly upregulated in the abdominal fat tissues of fat chickens compared to lean chickens,and its expression gradually increases during the proliferation and adipogenic differentiation of chicken abdominal preadipocytes.Functionally,the gain-and loss-of-function experiments showed that circDOCK7 promoted proliferation,G0/G1-to S-phase progression,and glucose uptake capacity of chicken abdominal preadipocytes,in parallel with adipogenic differentiation characterized by remarkably increased intracellular lipid droplet accumulation and triglyceride and acetyl coenzyme A content in differentiated chicken abdominal preadipocytes.Mechanistically,a pull-down assay and a dual-luciferase reporter assay confirmed that circDOCK7 interacted with gga-miR-301b-3p,which was identified as an inhibitor of chicken abdominal adipogenesis.Moreover,the ACSL1 gene was demonstrated to be a direct target of gga-miR-301b-3p.Chicken ACSL1 protein is localized in the endoplasmic reticulum and mitochondria of chicken abdominal preadipocytes and acts as an adipogenesis accelerator.Rescue experiments showed that circDOCK7 could counteract the inhibitory effects of gga-miR-301b-3p on ACSL1 mRNA abundance as well as the proliferation and adipogenic differentiation of chicken abdominal preadipocytes.Conclusions CircDOCK7 serves as a miRNA sponge that directly sequesters gga-miR-301b-3p away from the ACSL1 gene,thus augmenting adipogenesis in chickens.These findings may elucidate a new regulatory mechanism underlying abdominal fat deposition in chickens.

林甸鸡腹部脂肪组织发育规律探究

肉鸡生产过程中腹脂过度沉积会造成生产效率下降等一系列问题。林甸鸡作为优质地方鸡种之一,产蛋、产肉性能优良,肉质鲜美,深受大众喜爱。为探究林甸鸡腹部脂肪组织发育规律,测定林甸鸡3~22周龄体重及腹脂重,观察并统计腹部脂肪细胞大小和数量,分析脂肪细胞特性与腹脂沉积之间关系。结果表明,林甸鸡在3~22周龄体重持续增长,腹脂重先升后降再升,腹脂率先降后升;3~10周龄脂肪细胞以增生为主,10~14周龄脂肪细胞以增大占优,19周龄后脂肪细胞增大和增生同时进行,但以增大为主。研究初步确定腹脂重与脂肪细胞特性回归模型,发现脂肪细胞体积对腹脂重的影响最大。试验结果为选育优质特色林甸鸡新品系提供理论参考。

不同包装方式对烤鸡货架期及菌群多样性的影响

烤鸡是一种独特的即食鸡肉产品,由于其独特的烹饪方式使其皮脆肉嫩,深受消费者喜爱。然而目前烤鸡包装方式仍然较单一,使得烤鸡的货架期较短。该研究基于此,对比分析5种不同包装方式A(普通包装)、B(100%N_(2))、C(CO_(2)∶N_(2)为2∶8)、D(CO_(2)∶N_(2)为3∶7)和E(CO_(2)∶N_(2)为4∶6)对烤鸡脂肪氧化、色度变化及微生物总量的影响。研究结果表明,采用气调包装方式的烤鸡明显优于普通包装方式;当使用气调包装方式时,随着气调包装中CO_(2)比例的增加,烤鸡中微生物生长速率和脂肪氧化速率明显降低,说明适当提高气调包装中CO_(2)比例能够有效延长烤鸡的货架期。

去势对武定鸡胸肌组织脂质组成的影响

为揭示去势对鸡胸肌组织脂质组成的影响,试验采用索氏提取法和UHPLC/Q-TOF-MS检测技术对去势组和假手术组武定鸡肌肉组织进行肌内脂肪(IMF)含量测定和非靶向脂质组学研究。结果显示:去势组武定鸡胸肌组织IMF含量显著高于假手术组(P<0.05);脂质组学检测到21种脂质亚类和553个脂质分子,其中去势组胸肌组织单糖基神经酰胺(CerG1)、脂肪酸(FA)、溶血磷脂酰甘油(LPG)、溶血磷脂乙醇胺(LPE)、溶血磷脂酰丝氨酸(LPS)、辅酶(Co)、磷脂酰甘油(PG)、神经酰胺(Cer)、磷脂酰乙醇胺(PE)、鞘氨醇(So)、甘油二酯(DG)、心磷脂(CL)、磷脂酰胆碱(PC)、甘油三酯(TG)、酰基肉碱(AcCa)、磷脂酰肌醇(PI)和磷脂酰丝氨酸(PS)丰度上调,溶血磷脂酰胆碱(LPC)、鞘磷脂(SM)、溶血磷脂酰肌醇(LPI)、单半乳糖基二酰甘油酯(MGDG)丰度下调;筛选出16种差异脂质分子,其中去势组胸肌组织PE(18∶1p/20∶4)、PE(18∶0/18∶1)、PE(38∶2p)、PE(18∶0e/22∶6)、PC(38∶6)、PC(34∶1e)、PS(41∶4)、PS(18∶0/22∶4)、LPC(22∶5)、LPI(20∶4)、PI(16∶0/20∶4)、Cer(d18∶1/24∶1)、Cer(d18∶1/24∶1)、TG(16∶0/8∶0/16∶0)丰度上调,PC(39∶5)和PI(16∶0/20∶3)丰度下调(VIP>1,P<0.05)。结果表明,去势促进武定鸡胸肌组织IMF沉积,影响脂质组成,改善肉质特性。

鸡腹脂中四种天然黄色素的检测方法研究

为研究鸡腹脂中四种不同天然色素含量的HPLC检测方法,实验对5种不同来源的鸡腹脂进行色素成分的检测分析。样品经含有0.5%BHT的二氯甲烷/乙腈(3:2,V/V)混合溶剂萃取,10%无水硫酸钠溶液及正己烷分离,有机相合并浓缩后正己烷溶解定容,部分溶液加入2 mL的40%氢氧化钾甲醇溶液涡旋皂,1 mL醋酸酸化后利用10%无水硫酸钠溶液及正己烷分离,有机相合并浓缩后正己烷溶解,利用无水硫酸钠分别将皂化前后溶液除水后0.22μm有机滤膜过滤上机检测;液相条件为正己烷/乙酸乙酯/异丙醇(730:270:15,V/V/V)等度洗脱,流速1.4 mL/min,445 nm波长进行检测。结果表明:本研究所建方法测定线性范围为0.31~1.57μg/mL,R^(2)=0.9999,RSD为2.68%~4.81%,检出限为0.05 mg/kg,当叶黄素添加量为0.8~3.3 mg/kg时,回收率为96.74%~109.10%;该方法能够满足同时检测鸡腹脂中四种不同天色黄色素成分含量,灵敏度高,重现性好,为研究鸡腹脂中黄色素的着色规律提供技术支持。

细胞周期蛋白依赖性激酶抑制因子3对鸡前脂肪细胞分化的抑制作用

【目的】解析细胞周期蛋白依赖性激酶抑制因子3(cyclin-dependent kinase inhibitor 3,CDKN3)在鸡前脂肪细胞分化中的作用,为阐明脂肪沉积的分子机制奠定理论基础。【方法】构建荧光表达载体pECFPCDKN3,转染至鸡永生化前脂肪细胞系(immortalized chicken preadipocyte cell line,ICP1),观察CDKN3蛋白的亚细胞定位;采用油酸钠诱导ICP1分化,qRT-PCR检测分化过程中CDKN3 mRNA表达水平;将pCMVHA-CDKN3和pCMV-HA分别转染到ICP1中,转染24 h后进行诱导分化,通过油红O染色检测脂肪细胞分化情况,并利用qRT-PCR检测过表达CDKN3后脂肪分化相关基因的mRNA表达水平。【结果】转染了pECFP-CDKN3的细胞主要在细胞核中呈青色荧光信号,提示鸡CDKN3定位于细胞核;在诱导ICP1成脂分化的过程中,CDKN3 mRNA表达量逐渐升高;油红O染色结果显示:过表达CDKN3细胞内脂滴聚集减少,且脂肪分化相关基因C/EBPα、PPARγ、FABP4和FAS的表达水平均呈下降趋势,其中FAS显著下降(P<0.05),PPARγ极显著下降(P<0.01)。【结论】CDKN3是核蛋白,可抑制鸡前脂肪细胞分化。

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 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.

Integrative analysis of miRNA and mRNA profiles reveals that gga-miR-106-5p inhibits adipogenesis by targeting the KLF15 gene in chickens

Background:Excessive abdominal fat deposition in commercial broilers presents an obstacle to profitable meat quality,feed utilization,and reproduction.Abdominal fat deposition depends on the proliferation of preadipocytes and their maturation into adipocytes,which involves a cascade of regulatory molecules.Accumulating evidence has shown that microRNAs(miRNAs)serve as post-transcriptional regulators of adipogenic differentiation in mammals.However,the miRNA-mediated molecular mechanisms underlying abdominal fat deposition in chickens are still poorly understood.This study aimed to investigate the biological functions and regulatory mechanism of miRNAs in chicken abdominal adipogenesis.Results:We established a chicken model of abdominal adipocyte differentiation and analyzed miRNA and mRNA expression in abdominal adipocytes at different stages of differentiation(0,12,48,72,and 120 h).A total of 217 differentially expressed miRNAs(DE-miRNAs)and 3520 differentially expressed genes were identified.Target prediction of DE-miRNAs and functional enrichment analysis revealed that the differentially expressed targets were significantly enriched in lipid metabolism-related signaling pathways,including the PPAR signaling and MAPK signaling pathways.A candidate miRNA,gga-miR-106-5p,exhibited decreased expression during the proliferation and differentiation of abdominal preadipocytes and was downregulated in the abdominal adipose tissues of fat chickens compared to that of lean chickens.gga-miR-106-5p was found to inhibit the proliferation and adipogenic differentiation of chicken abdominal preadipocytes.A dual-luciferase reporter assay suggested that the KLF15 gene,which encodes a transcriptional factor,is a direct target of gga-miR-106-5p.gga-miR-106-5p suppressed the posttranscriptional activity of KLF15,which is an activator of abdominal preadipocyte proliferation and differentiation,as determined with gain-and loss-of-function experiments.Conclusions:gga-miR-106-5p functions as an inhibitor of abdominal adipogenesis by targeting the KLF15 gene in chickens.These findings not only improve our understanding of the specific functions of miRNAs in avian adipogenesis but also provide potential targets for the genetic improvement of excessive abdominal fat deposition in poultry.

Haplotypes at the 5′-Flanking Region of Peroxisome Proliferator-Activated Receptor γ Gene and Their Association with the Growth and Body Composition Traits in Chickens

Peroxisome proliferator-activated receptor g（PPARg） is an important regulator of chicken preadipocyte proliferation and differentiation.In this study,polymorphisms were detected by DNA sequencing,PCR-RFLP and some other methods and three polymorphisms（g.-1784_-1768del17,c.-1241GA and c.-75GA） were found in the 5＇ flanking region of PPARg gene.Growth and body composition traits were measured in the 8th-10th generation populations of the Northeast Agricultural University broiler lines were divergently selected for abdominal fat content.Polymorphisms among individuals were screened in the above populations.The haplotype-based association analysis on growth and body composition traits was carried out.The association analysis showed that haplotypes based on three polymorphisms at 5＇ flanking region of PPARg gene were significantly associated with abdominal fat weight（AFW）,abdominal fat percentage（AFP,AFW/BW7）,liver weight（LW）,liver weight percentage（LFP,LW/BW7）,shank length（ShL）,femur weight（FeW）,keel length（KeL）,and metatarsus circle（MeC）（P0.05） and suggestive significantly associated with pectoralis major weight（PMaW）,pectoralis minor weight（PMiW）,pectoralis minor weight percentage（PMiWP,PMiW/BW7）,and metatarsus length（MeL）（P0.2）.The least square analysis showed that the birds with BGA haplotype had significantly higher AFW and AFP than the birds with other haplotypes（P0.05）.The birds with AAG haplotype had significantly higher LW and LW/BW than the birds with other haplotypes（P0.05）.The birds with AAG haplotype had significantly higher PMiW and PMiW/BW than the birds with other haplotypes（P0.05）.The birds with AAG haplotype had significantly higher ShL,FeW,MeL,MeC and KeL than the birds with AGG haplotypes（P0.05）.The results in this study revealed that QTL affecting fatness traits may exist in 5＇ flanking region of PPARg gene in chickens and PPARg gene might be one of the genes having important influences on the growth and bone traits in chickens.