Liver dominant expression of fatty acid synthase (FAS) gene in two chicken breeds during intramuscular-fat development

Fatty acid synthase (FAS) is a key enzyme of lipogenesis. In this study, the FAS mRNA expression patterns were examined in three fat related tissues (liver, breast and thigh) at different developmental stages in two chicken breeds (Beijing-You, BJY and Arbor Acres broiler, AA). Results of the Real time-qPCR showed that the expression of FAS mRNA level in liver was significantly higher (P < 0.01) than that in breast and thigh in both two chicken breeds. Significant differences of FAS mRNA expression in liver were found between BJY and AA chickens during different developmental stages. After the contents of intramuscular-fat (IMF) and the liver fat were measured, the correlation analysis was performed. In liver, the FAS mRNA level was highly correlated with hepatic fat content (r = 0.891, P < 0.01 for BJY; r = 0.901, P < 0.01 for AA). On the contrary, the FAS expression level in both breast and thigh tissues were relatively low, stable and there was no correlation between the FAS mRNA level and IMF content in breast and thigh tissues of each breed. The results here can contribute to the knowledge on the developmental expression pattern of FAS mRNA and facilitate the further research on the molecular mechanism underlying IMF deposition in chicken.     

Molecular cloning of the goose ACSL3 and ACSL5 coding domain sequences and their expression characteristics during goose fatty liver development

It has been demonstrated that ACSL3 and ACSL5 play important roles in fat metabolism. To investigate the primary functions of ACSL3 and ACSL5 and to evaluate their expression levels during goose fatty liver development, we cloned the ACSL3 and ACSL5 coding domain sequences (CDSs) of geese using RT-PCR and analyzed their expression characteristics under different conditions using qRT-PCR. The results showed that the goose ACSL3 (JX511975) and ACSL5 (JX511976) sequences have high similarities with the chicken sequences both at the nucleotide and amino acid levels. Both ACSL3 and ACSL5 have high expression levels in goose liver. The expression levels of ACSL3 and ACSL5 in goose liver and hepatocytes can be changed by overfeeding geese and by treatment with unsaturated fatty acids, respectively. Together, these results indicate that ACSL3 and ACSL5 play important roles during fatty liver development. The different expression characteristics of goose ACSL3 and ACSL5 suggest that these two genes may be responsible for specific functions.     

Cloning and characterization of chicken adipocyte fatty acid binding protein gene

Fatty acid binding proteins (FABPs) are members of a superfamily of lipid-binding proteins and occur intracellularly in vertebrates and invertebrates. This study was designed to clone and characterize the adipocyte fatty acid binding protein (A-FABP) gene in the chicken. PCR primers were designed according to mammalian A-FABP gene sequence to amplify partial cDNA of A-FABP gene from chicken adipose tissues, and the full length of the gene was cloned by 5'RACE and 3'RACE. Analysis of sequence showed that the cDNA of the chicken A-FABP gene was 74 and 73% homologous with porcine and human A-FABP gene, respectively. The similarity was 77, 28, and 23% at the predicted amino acid level with human A-FABP, human L-FABP, and human I-FABP, respectively. RT-PCR and Northern blot analysis indicated that the chicken A-FABP gene, similar to that of the mammal, is only expressed in fat tissues. This is the first report to identify and characterize A-FABP gene in the chicken.     

鸡缺氧诱导因子-1[[alpha]]基因的差异表达与低氧适应性

低氧诱导因子-1(HIF-1)是在低氧的癌细胞中发现的一种转录激活因子, 在生物体氧平衡调节中起关键作用。藏鸡是对高原低氧、低温环境有着极强适应能力的高原土著品种, 相对而言, 白来航鸡和寿光鸡为两个低地鸡种。在常氧环境下对这3个鸡品种进行全期模拟低氧孵化, 结果显示, 藏鸡的孵化率显著高于两个低地鸡品种, 表现出了高度的耐受低氧环境的能力, 而对于低地鸡, 一定程度的低氧环境对其孵化是致命的。利用Taqman探针法FQRT-PCR技术检测了藏鸡、白来航鸡、寿光鸡HIF-1[[alpha]] 的组织特异性表达。结果表明, HIF-1[[alpha]] mRNA在3个鸡品种的大脑和骨骼肌组织均有表达, 并有明显的组织差异性, 脑的表达量最大; 并且发现常氧条件下孵化时, 藏鸡胚胎的大脑组织内HIF-1[[alpha]] 基因的表达量与低氧孵化的低地鸡胚胎相接近.     

Isolation and characterization of a fatty acid binding protein in adipose tissue of Gallus domesticus.

1. Fatty acid binding protein (A-FABP) was isolated from chicken adipose cytosol. 2. Relative mol. wt of chicken A-FABP was determined to be 14,400 from SDS-polyacrylamide electrophoresis; the pI was 5.1; and amino acid composition data indicated structural homology with mammalian heart and adipose FABPs. 3. Polyclonal antisera prepared against A-FABP exhibited monospecificity for chicken A-FABP and no cross-reactivity with chicken liver proteins was observed. 4. Determination of relative ligand binding characteristics indicated A-FABP exhibited greatest binding activity in response to linoleate, followed by oleate, palmityl CoA and palmitate; no binding affinity for cholesterol was detected.     

Sequencing and alignment of mitochondrial genomes of Tibetan chicken and two lowland chicken breeds

Tibetan chicken lives in high-altitude area and has adapted well to hypoxia genetically. Shouguang chicken and Silky chicken are both lowland chicken breeds. In the present study, the complete mito-chondrial genome sequences of the three chicken breeds were all sequenced. The results showed that the mitochondrial DNAs (mtDNAs) of Shouguang chicken and Silky chicken consist of 16784 bp and 16785 bp respectively, and Tibetan chicken mitochondrial genome varies from 16784 bp to 16786 bp. After sequence analysis, 120 mutations, including 4 single nucleotide polymorphisms (SNPs) in tRNA genes, 9 SNPs and 1 insertion in rRNA genes, 38 SNPs and 1 deletion in D-LOOP, 66 SNPs in pro-tein-coding genes, were found. This work will provide clues for the future study on the association between mitochondrial genes and the adaptation to hypoxia.Tibetan chicken, lowland chicken, mitochondrial genome, hypoxia.     

Sequencing and alignment of mitochondrial genomes of Tibetan chicken and two lowland chicken breeds

Tibetan chicken lives in high-altitude area and has adapted well to hypoxia genetically. Shouguang chicken and Silky chicken are both lowland chicken breeds. In the present study, the complete mitochondrial genome sequences of the three chicken breeds were all sequenced. The results showed that the mitochondrial DNAs (mtDNAs) of Shouguang chicken and Silky chicken consist of 16784 bp and 16785 bp respectively, and Tibetan chicken mitochondrial genome varies from 16784 bp to 16786 bp. After sequence analysis, 120 mutations, including 4 single nucleotide polymorphisms (SNPs) in tRNA genes, 9 SNPs and 1 insertion in rRNA genes, 38 SNPs and 1 deletion in D-LOOP, 66 SNPs in protein-coding genes, were found. This work will provide clues for the future study on the association between mitochondrial genes and the adaptation to hypoxia.     

Parallel Evolution of Polydactyly Traits in Chinese and European Chickens

Polydactyly is one of the most common hereditary congenital limb malformations in chickens and other vertebrates. The zone of polarizing activity regulatory sequence (ZRS) is critical for the development of polydactyly. The causative mutation of polydactyly in the Silkie chicken has been mapped to the ZRS; however, the causative mutations of other chicken breeds are yet to be established. To understand whether the same mutation decides the polydactyly phenotype in other chicken breeds, we detected the single-nucleotide polymorphism in 26 different chicken breeds, specifically, 24 Chinese indigenous breeds and 2 European breeds. The mutation was found to have fully penetrated chickens with polydactyly in China, indicating that it is causative for polydactyly in Chinese indigenous chickens. In comparison, the mutation showed no association with polydactyly in Houdan chickens, which originate from France, Europe. Based on the different morphology of polydactyly in Chinese and European breeds, we assumed that the trait might be attributable to different genetic foundations. Therefore, we subsequently performed genome-wide association analysis (GWAS) to locate the region associated with polydactyly. As a result, a ~0.39 Mb genomic region on GGA2p was identified. The region contains six candidate genes, with the causative mutation found in Chinese indigenous breeds also being located in this region. Our results demonstrate that polydactyly in chickens from China and Europe is caused by two independent mutation events that are closely located in the chicken genome.     

Interferon induction and/or production and its suppression by influenza A viruses

Developmentally aged chicken embryo cells which hyperproduce interferon (IFN) when induced were used to quantify IFN production and its suppression by eight strains of type A influenza viruses (AIV). Over 90% of the IFN-inducing or IFN induction-suppressing activity of AIV populations resided in noninfectious particles. The IFN-inducer moiety of AIV appears to preexist in, or be generated by, virions termed IFN-inducing particles (IFP) and was detectable under conditions in which a single molecule of double-stranded RNA introduced into a cell via endocytosis induced IFN, whereas single-stranded RNA did not. Some AIV strains suppressed IFN production, an activity that resided in a noninfectious virion termed an IFN induction-suppressing particle (ISP). The ISP phenotype was dominant over the IFP phenotype. Strains of AIV varied 100-fold in their capacity to induce IFN. AIV genetically compromised in NS1 expression induced about 20 times more IFN than NS1-competent parental strains. UV irradiation further enhanced the IFN-inducing capacity of AIV up to 100-fold, converting ISP into IFP and IFP into more efficient IFP. AIV is known to prevent IFN induction and/or production by expressing NS1 from a small UV target (gene NS). Evidence is presented for an additional downregulator of IFN production, identified as a large UV target postulated to consist of AIV polymerase genes PB1 + PB2 + PA, through the ensuing action of their cap-snatching endonuclease on pre-IFN-mRNA. The products of both the small and large UV targets act in concert to regulate IFN induction and/or production. Knowledge of the IFP/ISP phenotype may be useful in the development of attenuated AIV strains that maximally induce cytokines favorable to the immune response.     

High diversity of the chicken growth hormone gene and effects on growth and carcass traits

The chicken growth hormone (cGH) gene plays a crucial role in controlling growth and metabolism, leading to potential correlations between cGH polymorphisms and economic traits. In this study, DNA from four divergent chicken breeds were screened for single nucleotide polymorphisms (SNPs) in the cGH gene using denaturing high-performance liquid chromatography and sequencing. A total of 46 SNPs were identified, of which 4 were in the 5' untranslated region, 1 in the 3' untranslated region, 5 in exons (two of which are nonsynonymous), with the remaining 36 in introns. The nucleotide diversity in the cGH gene ( theta = 2.7 x 10(-3)) was higher than that reported for other chicken genes, even within the same breeds. The associations of five of these SNPs and their haplotypes with chicken growth and carcass traits were determined using polymerase chain reaction-restriction fragment length polymorphism analysis in a F2 resource population cross of two of the four chicken breeds (White Recessive Rock and Xinghua). This analysis shows that, among other correlations, G+1705A was significantly associated with body weight at all ages measured, shank length at three of four ages measured, and average daily gain within weeks 0 to 4. Thus, this cGH polymorphism, or another polymorphism that is in linkage disequilibrium with G+1705A, appears to correspond to a significant growth-related quantitative trait locus difference between the two breeds used to construct the resource population.     

Polymorphisms of Chicken TLR3 and 7 in Different Breeds

Toll-like receptors (TLRs) mediate immune responses via the recognition of pathogen-associated molecular patterns (PAMPs), thus playing important roles in host defense. Among the chicken (Ch) TLR family, ChTLR3 and 7 have been shown to recognize viral RNA. In our earlier studies, we have reported polymorphisms of TLR1, 2, 4, 5, 15 and 21. In the present study, we amplified TLR3 and 7 genes from different chicken breeds and analyzed their sequences. We identified 7 amino acid polymorphism sites in ChTLR3 with 6 outer part sites and 1 inner part site, and 4 amino acid polymorphism sites in ChTLR7 with 3 outer part sites and 1 inner part site. These results demonstrate that ChTLR genes are polymorphic among different chicken breeds, suggesting a varied resistance across numerous chicken breeds. This information might help improve chicken health by breeding and vaccination.     

中外11个猪种A-FABP基因微卫星遗传变异的研究

利用微卫星技术对五指山猪、沂蒙黑猪、汉江黑猪、莱芜猪、北京黑猪、民猪、成华猪、内江猪、二花脸猪、巴马香猪和大白猪11个猪种共420头猪的脂肪细胞脂肪酸结合蛋白基因内含子的微卫星序列的遗传变异进行了研究。研究表明：（1）中国猪种在A-FABP基因微卫星基因座上有极高的的多态性,五指山猪的PIC最高（PIC=0.7904）并检测到11个等位基因,但北京黑猪仅检测到两个等位基因。（2）本实验中,只有北京黑猪、民猪、巴马香猪和大白猪A-FABP基因微卫星在群体中的分布达到平衡状态。（3）群体间的基因分化系数分析表明,中国猪种在该微卫星基因座上分化程度平均约为40.83%。Abstract：The genetic variations of microsatellites in intron 2 of the porcine adipocyte fatty acid-binding protein (A-FABP) genes were investigated in 420 pigs including Wuzhishan pig,Yimeng black pig,Hanjiang black pig,Laiwu pig,Beijing black pig,Min pig,Chenghua pig,Neijiang pig,Erhualian pig,Bama xiang pig and Large White pig.The results suggested as follows：（i）PIC of the Wuzhishan pig breed is the highest（0.7904） and 11 alleles were detected. Compared with Large White pig,Chinese pig breeds showed a great polymorphism of A-FABP microsatellites except Beijing black pig in which only 2 alleles were detected.（ii）Only Min pig, Bama xiang pig, Beijing black pig and Large White pig were in Hardy-Weinberg equilibrium. （iii）The analysis of genetic differentiation showed that the average value of the A-FABP gene differentiation of 10 Chinese pigs is about 40.83%.     

Analysis of genetic diversity and phylogenetic relationships among red jungle fowls and Chinese domestic fowls

Genetic diversity and phylogenetic relationships among 568 individuals of two red jungle fowl subspe- cies (Gallus gallus spadiceus in China and Gallus gallus gallus in Thailand) and 14 Chinese domestic chicken breeds were evaluated with 29 microstaellite loci, the genetic variability within population and genetic differentiation among population were estimated, and then genetic diversity and phylogenetic relationships were analyzed among red jungle fowls and Chinese domestic fowls. A total of 286 alleles were detected in 16 population with 29 microsatellite markers and the average number of the alleles observed in 29 microsatellite loci was 9.86±6.36. The overall expected heterozygosity of all population was 0.6708±0.0251, and the number of population deviated from Hardy-Weinberg equilibrium per locus ranged from 0 to 7. In the whole population, the average of genetic differentiation among population, measured as FST value, was 16.7% (P<0.001), and all loci contributed significantly (P<0.001) to this differentiation. It can also be seen that the deficit of heterozygotes was very high (0.015) (P<0.01). Reynolds' distance values varied between 0.036 (Xiaoshan chicken-Luyuan chicken pair) and 0.330 (G. gallus gallus-Gushi chicken pair). The Nm value ranged from 0.533 (between G. gallus gallus and Gushi chicken) to 5.833 (between Xiaoshan chicken and Luyuan chicken). An unrooted consensus tree was constructed using the neighbour-joining method and the Reynolds' genetic distance. The heavy-body sized chicken breeds, Luyuan chicken, Xiaoshan chicken, Beijing Fatty chicken, Henan Game chicken, Huainan Partridge and Langshan chicken formed one branch, and it had a close genetic relationship between Xiaoshan chicken-Luyuan chicken pair and Chahua chicken-Tibetan chicken pair. Chahua chicken and Tibetan chicken had closer genetic relationship with these two subspecies of red jungle fowl than other domestic chicken breeds. G. gallus spadiceus showed closer phylogenetic relationship with Chinese domestic chicken breeds than G. gallus gallus. All 29 microstaellite loci in this study showed high levels of polymorphism and significant genetic differentiation was observed among two subspecies of red jungle fowl and 14 Chinese domestic chicken breeds. The evolutional dendrogram is as follows: evolutional breeds→primitive breeds (Chahua chicken and Tibetan)→red jungle fowl in China (G. gallus spadiceus)→red jungle fowl in Thailand (G. gallus gallus). The results supported the theory that the domestic fowls might originate from different subspecies of red jungle fowl and Chinese domestic fowls had independent origin.     

Combined Haplotypes of CaSR Gene Sequence Variants and Their Associations with Growth Traits in Cattle

The calcium-sensing receptor (CaSR) is a Class C G-protein coupled receptor that regulates food intake and assimilation. However, studies on the relationship between CaSR gene and growth traits in cattle are deficient. The aim of this study was to examine the association of the CaSR polymorphism with growth traits in cattle breeds. Four novel single nucleotide polymorphisms (SNPs) and one previously reported SNP (NC_007299.5: g.67630865T>C, 67638409G>C, 67660395G>C, 67661546C>G, and 67661892A>C) were identified in the bovine CaSR gene using DNA sequencing and PCR-SSCP methods in 520 individuals from three representative breeds. The three SNP P4_2, P7_1, and P7_4 in LX, QC, and JX cattle populations belonged to intermediate genetic diversity (0.25?相似文献   

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。     

Wide-gene expression analysis of lipid-relevant genes in nutritionally challenged gilthead sea bream (Sparus aurata)

Disturbances of lipid metabolism are a major problem in livestock fish and the present study analysed the different tissue expression patterns and regulations of 40 lipid-relevant genes in gilthead sea bream. Nineteen sequences, including fatty acid elongases (4), phospholipases (7), acylglycerol lipases (8) and lipase-maturating enzymes (1), were new for gilthead sea bream (GenBank, JX975700, JX975701, JX975702, JX975703, JX975704, JX975705, JX975706, JX975707, JX975708, JX975709, JX975710, JX975711, JX975712, JX975713, JX975714, JX975715, JX975716, JX975717 and JX975718). Up to six different lipase-related enzymes were highly expressed in adipose tissue and liver, which also showed a high expression level of Δ6 and Δ9 desaturases. In the brain, the greatest gene expression level was achieved by the very long chain fatty acid elongation 1, along with relatively high levels of Δ9 desaturases and the phospholipase retinoic acid receptor responder. These two enzymes were also expressed at a high level in white skeletal muscle, which also shared a high expression of lipid oxidative enzymes. An overall down-regulation trend was observed in liver and adipose tissue in response to fasting following the depletion of lipid stores. The white skeletal muscle of fasted fish showed a strong down-regulation of Δ9 desaturases in conjunction with a consistent up-regulation of the “lipolytic machinery” including key enzymes of tissue fatty acid uptake and mitochondrial fatty acid transport and oxidation. In contrast, the gene expression profile of the brain remained almost unaltered in fasted fish, which highlights the different tissue plasticity of lipid-related genes. Taken together, these findings provide new fish genomic resources and contribute to define the most informative set of lipid-relevant genes for a given tissue and physiological condition in gilthead sea bream.     

Genetic diversity of Guangxi chicken breeds assessed with microsatellites and the mitochondrial DNA D-loop region

The domestic chicken (Gallus gallus domesticus) is an excellent model for genetic studies of phenotypic diversity. The Guangxi Region of China possesses several native chicken breeds displaying a broad range of phenotypes well adapted to the extreme hot-and-wet environments in the region. We thus evaluated the genetic diversity and relationships among six native chicken populations of the Guangxi region and also evaluated two commercial breeds (Arbor Acres and Roman chickens). We analyzed the sequences of the D-loop region of the mitochondrial DNA (mtDNA) and 18 microsatellite loci of 280 blood samples from six Guangxi native chicken breeds and from Arbor Acres and Roman chickens, and used the neighbor-joining method to construct the phylogenetic tree of these eight breeds. Our results showed that the genetic diversity of Guangxi native breeds was relatively rich. The phylogenetic tree using the unweighed pair-group method with arithmetic means (UPGAM) on microsatellite marks revealed two main clusters. Arbor Acres chicken and Roman chicken were in one cluster, while the Guangxi breeds were in the other cluster. Moreover, the UPGAM tree of Guangxi native breeds based on microsatellite loci was more consistent with the genesis, breeding history, differentiation and location than the mtDNA D-loop region. STRUCTURE analysis further confirmed the genetic structure of Guangxi native breeds in the Neighbor-Net dendrogram. The nomenclature of mtDNA sequence polymorphisms suggests that the Guangxi native chickens are distributed across four clades, but most of them are clustered in two main clades (B and E), with the other haplotypes within the clades A and C. The Guangxi native breeds revealed abundant genetic diversity not only on microsatellite loci but also on mtDNA D-loop region, and contained multiple maternal lineages, including one from China and another from Europe or the Middle East.