Age-related expression profile of the <Emphasis Type="Italic">SLC27A1</Emphasis> gene in chicken tissues

The solute carrier family 27 (SLC27, also known as fatty acid transport proteins [FATPs]) plays important biological roles in cells. However, there is no report about the expression profile of SLC27 member in chicken. In this study, we quantified the expression of SLC27A1 (FATP1) mRNA in a mountainous black-boned chicken breed (MB) and a commercial meat type chicken breed (S01), to discern the tissue and age-related specific expression pattern and their potential involvement in fat deposition and muscle fatty acid metabolism. Real-time quantitative PCR assays were developed for accurate measurement of SLC27A1 mRNA levels in different tissues from chicken with different ages (0–12 weeks). Expression of SLC27A1 mRNA was detected in all tissues examined. There was a significantly age-related change of the SLC27A1 mRNAs in heart, breast muscle (BMW), leg muscle (LMW), liver, and abdominal fat (AF) tissues (P < 0.05). The breast muscle and leg muscle tissues had the highest expression of SLC27A1 mRNA than the other tissues from the same individual at 0, 2 and 4 weeks. The overall SLC27A1 mRNA level exhibited a “rise-decline” developmental change in all tissues except for breast muscle, subcutaneous fat, and brain. The S01 chicken had a higher expression of the SLC27A1 mRNA in breast muscle, subcutaneous fat, and heart tissues than the MB chicken. Our results showed that the expression of SLC27A1 mRNA in chicken tissues exhibits specific developmental changes and age-related patterns.     

Characterization of the expression profiles of calpastatin (CAST) gene in chicken

The calpain system, a Ca²⁺-activated protease family, plays an important role in postmortem tenderization of skeletal muscle due to its involvement in the degradation of important myofibrillar and associated proteins, as well as in cytoskeletal remodeling and regulation of muscle growth. In this study, we quantified the expression of calpastatin (CAST) in two Chinese chicken breeds (mountainous black-bone chicken breed (MB) and a commercial meat type chicken breed (S01)), to discern the tissue and age-related specific expression pattern and its potential role on muscle tissue metabolism. Real-time quantitative PCR (RT-qPCR) assay was developed for accurate measurement of CAST mRNA levels in various tissues from chicken with different ages (0, 2, 4, 6, 8, 10, and 12 week). CAST mRNA was detected in collected organs. The heart and leg muscle tissues had the highest expression of CAST than other tissues from the same chicken (P < 0.01). Age-related expression pattern of CAST gene was evident in breast muscle, liver, and brain tissues (P < 0.05), but not in heart and leg muscle tissues (P > 0.05). Overall, the CAST mRNA level exhibited a “rise-decline-rise-decline” developmental change in breast muscle and liver, with the highest expression at 2 weeks and the lowest expression at 8 weeks. The S01 chicken had significantly higher expression of CAST in breast muscle and heart than the MB chicken (P < 0.05) at 10 weeks. Our results suggested the CAST expression may be related to muscle fiber development.     

Identification and characterization of adipose triglyceride lipase (ATGL) gene in birds

Adipose triglyceride lipase (ATGL) is a triglyceride hydrolysis lipase and is generally related to lipid metabolism in animals. The ATGL gene was well studied in mammals, however very less was known in birds that differed significantly with mammals for lipid metabolism. In this study, cloning, mRNA real time and association analysis was performed to characterize the ATGL gene in birds. Results showed that the obtained ATGL gene cDNA of parrot, quail, duck were 1,651 bp (NCBI accession number: GQ221784), 1,557 bp (NCBI accession number: GQ221783) and 1,440 bp each, encoded 481-, 482- and 279-amino acid (AA) peptide, respectively. The parrot ATGL (pATGL) gene was found to predominantly express in breast muscle and leg muscle, and very higher ATGL mRNA level was also found in heart, abdominal fat and subcutaneous fat. The quail ATGL (qATGL) gene was also predominantly expressed in breast muscle and leg muscle, and then to a much lesser degree in heart. The duck ATGL (dATGL) gene was found to predominantly express in subcutaneous fat and abdominal fat, quite higher ATGL mRNA was also found in heart, spleen, breast muscle and leg muscle. Blast analyses indicated the high homology of ATGL and its patatin region, and moreover, and the active serine hydrolase motif (“GASAG” for “GXSXG”) and the glycine rich motif (“GCGFLG” for “GXGXXG”) were completely conservative among 14 species. Association analyses showed that c.950+24C>A, c.950+45C>G, c.950+73G>A, c.950+83C>T and c.950+128delA of chicken ATGL gene (cATGL) were all significantly or highly significantly with cingulated fat width (CFW) (P < 0.05 or P < 0.01), and c.777−26C>A, c.950+45C>G, c.950+73G>A and c.950+118C>T were all significantly or highly significantly with pH value of breast muscle (BMPH) (P < 0.05).     

Identification and association of novel lncRNA <Emphasis Type="BoldItalic">pouMU1</Emphasis> gene mutations with chicken performance traits

The biological functions of long noncoding RNAs (lncRNAs), which play an important role in regulating development and gene expression, may be affected by variations in lncRNA gene loci or associated genomic sequences. However, the functions of many lncRNAs remain unknown. To analyse correlations between mutations in pouMU1 with chicken growth and carcass traits, 860 chickens from a Gushi \(\times \) Anka F2 resource population and 96 Lushi, Xichuan, Changshun and recessive white chickens were used to evaluate the genetic effect of the pouMU1 gene. We performed quantitative real-time polymerase chain reaction (qRT-PCR) to analyse the relative expression levels of pouMU1 in nine different tissues and stages of development. pouMU1 expression was highest in pectoralis and leg muscles, whereas no expression was observed in the heart, liver and abdominal fat. Using direct sequencing and polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods, two novel sequence mutations (g.1198A>G and g.1238-1239del/insGA) were detected in the pouMU1 gene. SPSS software was used for statistical analysis in association studies. Based on the association data, the presence of both variants was significantly associated with leg muscle fibre width and leg muscle fibre roundness (\(P < 0.05\)) and highly associated with leg muscle fibre girth and body weight at 0 week of age (\(P < 0.01\)). These data suggest that pouMU1 might participate in regulating chicken muscle development and growth, and the findings offer new insight into the functions of sequence mutations in lncRNAs.     

Expression profiling of candidate genes for abdominal fat mass in domestic chicken <Emphasis Type="Italic">Gallus gallus</Emphasis>

The quantitative traits of mass and percentage of abdominal fat in chicken and various types of obesity in mammals are homologous and functionally similar. Therefore, the genes involved in obesity development in humans and laboratory rodents as well as those responsible for pig lard thickness could be involved in abdominal fat deposition in broilers. Expression of candidate genes FABP1, FABP2, FABP3, HMGA1, MC4R, PPARG, PPARGC1A, POMC and PTPN1 was studied in fat, liver, colon, muscle, pituitary gland, and brain in chicken (broilers) using real-time PCR. Significant difference in the HMGA1 gene expression in the liver of broiler chicken with high (3.5 ± 0.18%) and low (1.9 ± 0.56%) abdominal fat concentration has been revealed. The expression of this gene was been shown to correlate with the amount (0.7, P ≤ 0.01) and mass (0.7, P ≤ 0.01) of abdominal fat. The PPARG gene expression in liver in the same chicken subsets was also significantly different. Correlation coefficients of the gene expression with the abdominal fat amount and mass were respectively 0.55 (P ≤ 0.05) and 0.57 (P ≤ 0.01). Based on these results, we suggest that the HMGA1 and PPARG genes are involved in abdominal fat deposition. The search for single nucleotide polymorphisms (SNPs) in the HMGA and PPARG regulatory regions could facilitate identifying genetic markers for broiler breeding according to the mass and percentage of abdominal fat.     

Characterization of the expression profile of <Emphasis Type="Italic">calpain</Emphasis>-<Emphasis Type="Italic">3</Emphasis> (<Emphasis Type="Italic">CAPN3</Emphasis>) gene in chicken

Calpain-3 is a skeletal muscle-specific protease and participates in the regulation of myogenesis. In this study, we quantified the expression of calpain-3 (CAPN3) mRNA in a Chinese local chicken breed (Sichuan Mountainous Black-boned chicken [MB]), to discern the tissue and ontogenic expression pattern. Meanwhile, we compared the CAPN3 mRNA expression pattern in MB chicken at 10 weeks with a commercial meat type chicken line (S01) of the same age to identify the unique expression pattern under different genetic background. A real time quantitative PCR (qRT-PCR) assay was developed for an accurate measurement of its expression in various tissues from chickens at different ages (0, 2, 4, 6, 8, 10, and 12 weeks). Expression of the CAPN3 mRNA was detected in the selected tissues, regardless of age. The breast muscle and leg muscle tissues had a significantly higher expression than the other tissues from the same individual (P < 0.01). Overall, the CAPN3 mRNA level exhibited a “rise-decline” developmental change in detected tissues except for brain. The S01 chicken had a higher expression of the CAPN3 mRNA in detected tissues than the MB chicken at 10 weeks. The present expression data of chicken CAPN3 gene may provide some information to shed light on the tissue and ontogenic expression pattern during chicken development.     

A 51 bp indel polymorphism within the PTH1R gene is significantly associated with chicken growth and carcass traits

Parathyroid hormone (PTH) is a crucial regulator of calcium homeostasis and bone remodeling, and the parathyroid hormone 1 receptor (PTH1R) belongs to a class II G-protein-coupled receptor. PTH activates PTH1R, which mediates catabolic and anabolic processes in the skeleton. However, the functional mechanism of PTH1R has not been thoroughly elucidated in organisms. This study identified a 51 bp indel mutation in the first intron of the PTH1R gene and elucidated the effect of this gene mutation on the growth and carcass traits in chickens. The results indicated that the 51 bp indel was significantly associated with subcutaneous fat thickness, abdominal fat weight, body weight and daily gain over 4–8 weeks. Furthermore, we found that PTH1R gene expression was highest in the kidney and liver tissues, and it showed a trend of decreasing in leg and breast muscle tissues at different embryonic stages. In addition, we examined the expression of the three genotypes of the PTH1R gene in the liver, breast muscle and abdominal fat and found that the II genotype was significantly higher than the DD and ID genotypes. In summary, these findings suggest that the PTH1R gene can serve as a potential molecular marker for chicken breeding.     

The single nucleotide polymorphisms of the chicken myostatin gene are associated with skeletal muscle and adipose growth

Myostatin, a new member of the TGF-p superfamily, is predominantly expressed in skeletal muscle cells and functions as a negative regulator of skeletal muscle growth in animals. Recently, we have reported three single nucleotide polymorphisms (SNPs) in the chicken my-ostatin gene. Herein, we investigate the association of those SNPs with the production traits in a F2 chicken line derived from Broilers crossing to Silky with the least square analysis. The results show that the BB and AA genotypes are strongly associated with abdominal fat weight (AFW), abdominal fat percentage (AFP), and birth weight (BW) (P < 0.05). Breast muscle percentage (BMP) of the AA type is higher than that of the AB type. The breast muscle weight and breast muscle percentages of F2 individuals have significant difference between CC and DD genotypes (P< 0.05). Breast muscle weight (BMW) of EF birds is higher than that of EE birds (P< 0.05). In this report, we present the first genetic evidence to show that chicken myostatin not o     

鸡Myostatin基因单核苷酸多态性及其对屠体性状的遗传效应分析

以180只3个品系的温岭草鸡为材料, 采用PCR-RFLP方法对鸡MSTN基因外显子1的2个多态位点进行研究, 并分析对屠体性状的遗传效应。Bsh1236Ⅰ识别G(2100)A突变, 产生MN和NN 2种基因型, MspⅠ识别G(2109)A突变, 产生AA、AB和BB 3种基因型, 联合2个位点分析出现了5种基因型。基因型频率在品系间的c2检验表明差异均不显著(P＞0.05)。方差分析显示不同基因型的屠宰率有显著或极显著的差异(P＜0.01或P＜0.05)。多重比较显示：杂合型MN的腹脂重和屠宰率显著(P＜0.05)高于突变型NN; 杂合型AB的胸肌重和胸肌率显著(P＜0.01或P＜0.05 )高于基因型AA, 基因型AA的腹脂重和腹脂率都极显著(P＜0.01)高于突变型BB, 在腿肌重性状上, BB型显著(P＜0.05)低于AA型和AB型;2个位点联合分析时, NA/MA基因型的腹脂重、腹脂率和胸肌率均极显著(P＜0.01)高于或低于其他基因型。     

鸡MD基因5'侧翼区多态性与鸡生长和体组成性状的相关研究

苹果酸脱氢酶(Malate Dehydrogenase,MD)是一种氧化还原性酶,参与体内多种能量代谢反应.它可以催化苹果酸氧化脱羧生成丙酮酸和CO2,并使NADP+还原成NADPH,NADPH是脂肪酸合成所必需的载体,棕榈酸可以利用生成的NADPH来合成长链脂肪酸,MD的活性与脂肪酸合成效率之间存在密切的相关,MD也参与体内骨骼肌、心肌的能量代谢,并对肌纤维的生长有一定的调节作用.根据鸡MD基因的5侧翼区序列设计一对引物,用直接测序的方法在侧翼区检测多态性位点,在235bp(GenBank登录号U49693)处发现一个SNP位点,此位点是一个限制性内切酶(SphⅠ酶)发生变化的位点.以东北农业大学高低脂双向选择系的第8世代肉鸡和东农F2资源群体为实验材料,用PCR-RFLP的方法进行基因型分析,建立适合的统计模型,进行基因型与生长和体组成性状的相关分析.结果表明在高低脂系第8世代肉鸡中AA基因型个体的腹脂重和腹脂率显著高于BB基因型个体(P＜0.05);BB基因型个体的大胸肌重和大胸肌率显著高于AA基因型个体(P＜0.05).在东农F2资源家系中BB基因型个体的大胸肌重和大胸肌率显著高于AA和AB基因型个体(P＜0.05);AA基因型个体的肝脏重和肝脏率显著高于BB基因型个体(P＜0.05).综上所述,MD基因可能是影响鸡生长和体组成性状的主效基因或与控制生长和体组成性状的主效基因相连锁.     

Expression profiling of candidate genes for abdominal fat mass in domestic chicken Gallus gallus

The quantitative traits of mass and percentage of abdominal fat in chicken and various types of obesity in mammals are homologous and functionally similar. Therefore, the genes involved in obesity development in humans and laboratory rodents as well as those responsible for pig lard thickness could be involved in abdominal fat deposition in broilers. Expression of candidate genes FABP1, FABP2, FABP3, HMGA1, MC4R, PPARG, PPARGC1A, POMC and PTPN1 was studied in fat, liver, colon, muscle, hypophysis, and brain in chicken (broilers) using real-time PCR. Significant difference in the HMGA1 gene expression in the liver of broiler chicken with high (3.5 +/- 0.18%) and low (1.9 +/- 0.56%) abdominal fat concentration has been revealed. The expression of this gene was been shown to correlate with the amount (0.7, P < or = 0.01) and mass (0.7, P < or = 0.01) of abdominal fat. The PPARG gene expression in liver in the same chicken subsets was also significantly different. Correlation coefficients of the gene expression with the abdominal fat amount and mass were respectively 0.55 (P < or = 0.05) and 0.57 (P < or = 0.01). Based on these results, we suggest that the HMGA1 and PPARG genes are involved in abdominal fat deposition. The search for single nucleotide polymorphisms (SNPs) in the HMGA and PPARG regulatory regions could facilitate identifying genetic markers for broiler breeding according to the mass and percentage of abdominal fat.     

Racial Differences in Insulin Resistance and Mid‐Thigh Fat Deposition in Postmenopausal Women

Objective: To determine whether racial differences in insulin resistance between African American (AA) and white women exist in postmenopausal women and whether they are related to physical fitness and/or obesity. Research Methods and Procedures: We studied 35 obese AA (n = 9) and white (n = 26) women of comparable maximal oxygen consumption, obesity, and age. Total body fat was measured by DXA. Abdominal and mid‐thigh low‐density lean tissue (a marker of intramuscular fat) were determined with computed tomography. Glucose utilization (M) was measured during the last 30 minutes of a 3‐hour hyperinsulinemic‐euglycemic clamp. Insulin sensitivity was estimated from the relationship of M to the concentration of insulin during the last 30 minutes of the clamp. Results: The percentage of fat and total body fat mass were similar between AA and white women, whereas fat‐free mass was higher in African American women. Visceral adipose tissue was not different between groups, but subcutaneous abdominal fat was 17% higher in the AA than in the white women. AA women had an 18% greater mid‐thigh muscle area (p < 0.01) and a 34% greater mid‐thigh low‐density lean tissue area than the white women. Fasting glucose concentrations were not different, but fasting insulin concentrations were 29% higher in AA women. Glucose utilization was 60% lower in the AA women because of a lower non‐oxidative glucose disposal. Insulin sensitivity was 46% lower in the AA women. Discussion: AA postmenopausal women have more mid‐thigh intramuscular fat, lower glucose utilization, and are less insulin sensitive than white women despite comparable fitness and relative body fat levels.     

The single nucleotide polymorphisms of the chicken myostatin gene are associated with skeletal muscle and adipose growth

Myostatin, a new member of the TGF-ß superfamily, is predominantly expressed in skeletal muscle cells and functions as a negative regulator of skeletal muscle growth in animals. Recently, we have reported three single nucleotide polymorphisms (SNPs) in the chicken myostatin gene. Herein, we investigate the association of those SNPs with the production traits in a F₂ chicken line derived from Broilers crossing to Silky with the least square analysis. The results show that the BB and AA genotypes are strongly associated with abdominal fat weight (AFW), abdominal fat percentage (AFP), and birth weight (BW) (P < 0.05). Breast muscle percentage (BMP) of the AA type is higher than that of the AB type. The breast muscle weight and breast muscle percentages of F₂ individuals have significant difference between CC and DD genotypes (P < 0.05). Breast muscle weight (BMW) of EF birds is higher than that of EE birds (P < 0.05). In this report, we present the first genetic evidence to show that chicken myostatin not only plays an important role in controlling skeletal muscle growth and differentiation, but also may be involved in regulation of adipose growth in chicken.     

Caecal microbiota could effectively increase chicken growth performance by regulating fat metabolism

It has been established that gut microbiota influences chicken growth performance and fat metabolism. However, whether gut microbiota affects chicken growth performance by regulating fat metabolism remains unclear. Therefore, seven-week-old chickens with high or low body weight were used in the present study. There were significant differences in body weight, breast and leg muscle indices, and cross-sectional area of muscle cells, suggesting different growth performance. The relative abundance of gut microbiota in the caecal contents at the genus level was compared by 16S rRNA gene sequencing. The results of LEfSe indicated that high body weight chickens contained Microbacterium and Sphingomonas more abundantly (P < 0.05). In contrast, low body weight chickens contained Slackia more abundantly (P < 0.05). The results of H & E, qPCR, IHC, WB and blood analysis suggested significantly different fat metabolism level in serum, liver, abdominal adipose, breast and leg muscles between high and low body weight chickens. Spearman correlation analysis revealed that fat metabolism positively correlated with the relative abundance of Microbacterium and Sphingomonas while negatively correlated with the abundance of Slackia. Furthermore, faecal microbiota transplantation was performed, which verified that transferring faecal microbiota from adult chickens with high body weight into one-day-old chickens improved growth performance and fat metabolism in liver by remodelling the gut microbiota. Overall, these results suggested that gut microbiota could affect chicken growth performance by regulating fat metabolism.     

Effect of Changes in Fat Distribution on the Rates of Change of Insulin Response in Children

Objective: To develop mixed models for examining longitudinal associations between rates of change in visceral, subcutaneous abdominal, and total body fat with rates of change in fasting insulin (FI) and insulin sensitivity (SI) over 3 years in children. Research Methods and Procedures: Seventy-seven children (mean age, 8.3 years at baseline) from Birmingham, Alabama, with three or more annual measures of FI and SI were included. Abdominal fat was measured by computed tomography, and total body fat and lean tissue mass were measured by DXA. Mixed models examined the longitudinal associations between the baseline level/rate of change of different fat compartments and the rate of change in FI or SI. Results: An annual increase of ∼5% in FI was associated with 1 cm²/yr of visceral fat gain per year (p < 0.05), independent of subcutaneous abdominal fat. A 1-cm² difference in initial subcutaneous abdominal fat was associated with an ∼0.2% increase per year in FI (p < 0.02), independent of visceral fat. None of the rates of change in any of the fat measures was associated with the rate of change of SI. Discussion: The rate of change in visceral fat was positively associated with the rate of change in FI, independent of increasing subcutaneous abdominal fat; however, subcutaneous abdominal fat may be more predictive of the rate of change of FI than visceral or total fat. Therefore, growth-related increases in abdominal fat, particularly subcutaneous abdominal fat, may contribute to accelerating increases in FI, but have no effect on SI.     

鸡PPARγ基因的表达特性及其对脂肪细胞增殖分化的影响

为分析鸡PPARγ基因的组织表达特性及其在脂肪细胞增殖和分化过程中的功能,文章以东北农业大学高、低腹脂双向选择品系肉鸡为实验材料,利用Western blotting方法,检测PPARγ基因的组织表达特性及其在高、低脂系肉鸡腹部脂肪组织间的表达差异;采用RNAi技术,在鸡原代脂肪细胞中抑制PPARγ基因的表达后,通过MTT和油红O提取比色的方法,研究鸡PPARγ基因对脂肪细胞增殖和分化的调控作用;利用Real-timePCR和Western blotting技术,分析PPARγ基因表达下调后,其他脂肪细胞分化转录因子以及与脂肪细胞分化相关的重要基因的表达变化情况。结果表明,PPARγ基因在7周龄高脂系肉鸡腹部脂肪组织、肌胃、脾脏、肾脏组织中表达量较高,在心脏中表达量较低,在肝脏、胸肌、腿肌、十二指肠中未检测到表达信号;与高脂系相比,PPARγ基因在5和7周龄低脂系肉鸡腹部脂肪组织中的表达量较低(P<0.05);PPARγ基因的表达量下降后,鸡脂肪细胞的增殖能力增强,分化能力减弱;同时,C/EBPα、SREBP1、A-FABP、Perilipin1、LPL、IGFBP-2基因的表达量均下降(P<0.05)。由此可见,PPARγ基因的表达可能与肉鸡腹部脂肪的沉积有一定的关系,该基因可能是调控鸡脂肪细胞增殖与分化的关键因子。     

Body Fat Patterning,Hepatic Fat and Pancreatic Volume of Non-Obese Asian Indians with Type 2 Diabetes in North India: A Case-Control Study

ObjectiveTo evaluate body fat patterning and phenotype including hepatic fat and pancreatic volume of non-obese (BMI: < 25 kg/m²) Asian Indians with type 2 diabetes residing in North India.MethodsNon-obese patients with type 2 diabetes (n = 93) and non-obese, normo-glycemic subjects (n = 40) were recruited. BMI, waist & hip circumferences, skinfold thickness at 8 sites, body fat, lean mass and detailed abdominal fat evaluation [total abdominal fat, total subcutaneous fat (superficial, deep, anterior, and posterior), total intra-abdominal fat (intra-peritoneal, retroperitoneal)], liver span, grades of fatty liver and pancreatic volume were compared.ResultsWaist circumference, subscapular skinfolds and total truncal fat (on DEXA) were higher whereas calf, total peripheral skinfolds and total leg fat (on DEXA) lower in patients. Specifically, the following volumes were higher in cases as compared to controls; total abdominal fat (19.4%), total intra-abdominal fat (49.7%), intra-peritoneal fat (47.7%), retroperitoneal fat (70.7%), pancreatic volume (26.6%), pancreatic volume index (21.3%) and liver span (10.8%). In cases, significant positive correlations were observed for pancreatic volume with BMI, waist and hip circumferences, W-HR, subscapular, abdominal and total truncal skinfolds, truncal, total subcutaneous, total intra-abdominal, intra-peritoneal, retroperitoneal fat depots, liver span and fatty liver.ConclusionsIn non-obese Asian Indians with type 2 diabetes, subcutaneous and intra-abdominal obesity, including fatty liver, and pancreatic volume were higher and peripheral subcutaneous adiposity was lower than BMI matched non-diabetic subjects. Importantly, increased pancreatic volume in patients was highly correlated with multiple measures of abdominal obesity and liver fat.