Langshan Chicken Research Articles

Multivariate statistical regression analysis and relative quantification based on dimensional-reduction method to compare the taste-active components of different chicken breeds

To compare the difference of non-volatile taste-active flavor components of different chicken breeds, four Chinese native yellow feather broilers including Langshan chicken, Chongren chicken, Luyuan chicken and Wenchang chicken were used in the experiment. The contents of free amino acids, 5'-nucleotides and minerals were determined by standard method, and then five principal components were extracted from the multi-index system based on the principal component analysis (PCA). Combined with the Mahalanobis distance analysis method and sensory evaluation results, the advantages and characteristics of each chicken breed were evaluated. The results showed that different kinds of chicken had their own advantages in different evaluation dimensions. The Equivalent umami concentration (ECU) of Wenchang chicken, which had the highest content of amino acids, was 12 g monosodium glutamate (MSG)/100 g, indicating the umami taste of it was very intense. The indexes of Langshan chicken were relatively uniform, with slightly higher mineral content, its overall Mahalanobis distance score was more similar to the "best standard". According to the Mahalanobis distance score, although the difference in amino acid content among each species was the largest, the overall score was more affected by the content of minerals and nucleotides, and there was interaction between each nutrient, which had an impact on the overall Mahalanobis distance score. The sensory evaluation results indicated that Wenchang chicken was the most superior among the taste of the four varieties investigated. Finally, taste compounds affecting the difference of chicken varieties were analyzed by partial least squares regression (PLS), resulting in order of mineral (Ca2+, Mg2+, PO43−) > nucleotide (AMP, IMP) > amino acid. This could provide a theoretical basis for quantitative oriented flavor processing and consumer choice of chicken.Graphical

Comparative analysis of liver transcriptome reveals adaptive responses to hypoxia environmental condition in Tibetan chicken.

Tibetan chickens, which have unique adaptations to extreme high-altitude environments, exhibit phenotypic and physiological characteristics that are distinct from those of lowland chickens. However, the mechanisms underlying hypoxic adaptation in the liver of chickens remain unknown. RNA-sequencing (RNA-Seq) technology was used to assess the differentially expressed genes (DEGs) involved in hypoxia adaptation in highland chickens (native Tibetan chicken [HT]) and lowland chickens (Langshan chicken [LS], Beijing You chicken [BJ], Qingyuan Partridge chicken [QY], and Chahua chicken [CH]). A total of 352 co-DEGs were specifically screened between HT and four native lowland chicken breeds. Gene ontology and Kyoto encyclopedia of genes and genomes enrichment analyses indicated that these co-DEGs were widely involved in lipid metabolism processes, such as the peroxisome proliferator-activated receptors (PPAR) signaling pathway, fatty acid degradation, fatty acid metabolism and fatty acid biosynthesis. To further determine the relationship from the 352 co-DEGs, protein-protein interaction network was carried out and identified eight genes (ACSL1, CPT1A, ACOX1, PPARC1A, SCD, ACSBG2, ACACA, and FASN) as the potential regulating genes that are responsible for the altitude difference between the HT and other four lowland chicken breeds. This study provides novel insights into the molecular mechanisms regulating hypoxia adaptation via lipid metabolism in Tibetan chickens and other highland animals.

Sensory Evaluation Combined with Principal Component Analysis and Mahalanobis Distance to Compare the Volatile Flavor Substances of Different Chicken Species

To promote the development of yellow feather chicken industry in our country and optimize the better yellow feather chicken species for today's market, this study compared four representative local yellow feather chicken species (Langshan chicken, Chongren chicken, Luyuan chicken and Wenchang chicken) and measured the components of volatile flavor substances in their chest and leg muscles. Firstly, the main gas components were extracted by headspace extraction and GC-MS, and then the principal components were extracted by PCA, followed by Markov distance analysis, and finally, the differences among chicken species were analyzed based on the results of sensory evaluation. In this study, a total of 29 gas components were extracted, among which alcohols, aldehydes and ketones were the main odor components. Two principal components were extracted from the multi-index system through PCA, and the cumulative contribution rate was 85%. The evaluation results combined with Mahalanobis distance and sensory assessment showed that: Four gas content between different breeds of significant differences (P<0.05), the Luyuan chicken kept the lowest number in the aspects of aldehydes, alcohols and ketones, which meaned it had the best smell, and Luyuan chicken also occupied obvious advantagein the fat, green grass and smoke small. It could be concluded that the smell state of Luyuan chicken was the best among the four chicken species.

Genome-wide analysis of the role of DNA methylation in inbreeding depression of reproduction in Langshan chicken

Inbreeding depression of chicken reproduction is a major concern in the conservation of chicken genetic resources. To investigate the potential DNA methylation sites involved in the inbreeding depression of chicken reproduction, we carried out whole-genome bisulfite sequencing (WGBS) of hypothalamus and ovary tissues from the strongly and weakly inbred Langshan chickens, respectively. 5948 and 4593 differentially methylated regions (DMRs) were identified in the hypothalamus and ovary between the strongly and weakly inbred Langshan chickens, respectively. Large numbers of DMR-related genes (DMGs) were enriched in reproduction-related pathways. By combining the WGBS and transcriptome data, two DMRs in SRD5A1 and CDC27 genes were inferred as the most likely biomarkers of inbreeding depression of reproduction in Langshan chicken. Our study provides the first systematic investigation of the DNA methylation changes in strongly inbred chickens, and extends our understanding of the regulatory mechanisms underlying inbreeding depression in chicken reproduction.

Genomic diversity dynamics in conserved chicken populations are revealed by genome-wide SNPs

BackgroundMaintaining maximum genetic diversity and preserving breed viability in conserved populations necessitates the rigorous evaluation of conservation schemes. Three chicken breeds (Baier Yellow Chicken (BEC), Beijing You Chicken (BYC) and Langshan Chicken (LSC)) are currently in conservation programs in China. Changes in genetic diversity were measured by heterozygosity, genomic inbreeding coefficients, and autozygosity, using estimates derived from runs of homozygosity (ROH) that were identified using SNPs.ResultsNinety DNA samples were collected from three generations for each breed. In the most recent generation, the highest genetic diversity was observed in LSC, followed by BEC and BYC. Inbreeding coefficients based on ROH for the three breeds declined slightly between the first and middle generations, and then rapidly increased. No inbreeding coefficients exceeded 0.1. Population structure assessments using neighbor-joining tree analysis, principal components analysis, and STRUCTURE analysis indicated that no genetic differentiation existed within breeds. LD decay and ROH at different cut-off lengths were used to identify traces left by recent or ancient inbreeding. Few long ROH were identified, indicating that inbreeding has been largely avoided with the current conservation strategy. The observed losses in genetic diversity and occurrences of inbreeding might be consequences of sub-optimal effective population sizes.ConclusionsThe conserved Chinese chicken populations have high genomic diversity under the current conservation program (R: F). Furthermore, this study highlights the need to monitor dynamic changes in genetic diversity in conserved breeds over successive generations. Our research provides new insights into genetic diversity dynamics in conserved populations, and lays a solid foundation for improving conservation schemes.

Monitoring conservation effects on a Chinese indigenous chicken breed using major histocompatibility complex B-G gene and DNA Barcodes.

ObjectiveWe report monitoring conservation effect for a Chinese indigenous chicken (Langshan) breed using major histocompatibility complex (MHC) and DNA barcords.MethodsThe full length of MHC B-G gene and mitochondrial cytochrome oxidase I (COI) gene in generations 0, 5, 10, 15, 16, and 17 was measured using re-sequencing and sequencing procedures, respectively.ResultsThere were 292 single nucleotide polymorphisms of MHC B-G gene identified in six generations. Heterozygosity (He) and polymorphic information content (PIC) of MHC B-G gene in generations 10, 15, 16, and 17 remained stable. He and PIC of MHC B-G gene were different in six generations, with G10, G15, G16, G17 >G5>G0 (p<0.05). For the COI gene, there were five haplotypes in generations 0, 5, 10, 15, 16, and 17. Where Hap2 and Hap4 were the shared haplotypes, 164 individuals shared Hap2 haplotypes, while Hap1 and Hap3 were the shared haplotypes in generations 0 and 5 and Hap5 was a shared haplotype in generations 10, 15, 16, and 17. The sequence of COI gene in 6 generations was tested by Tajima’s and D value, and the results were not significant, which were consistent with neutral mutation. There were no differences in generations 10, 15, 16, and 17for measured phenotypic traits. In other generations, for annual egg production, with G5, G10, G15, G16, G17>G0 (p<0.05). For age at the first egg and age at sexual maturity, with G10, G15, G16, G17>G5>G0 (p<0.05).ConclusionCombined with the results of COI gene DNA barcodes, MHC B-G gene, and phenotypic traits we can see that genetic diversity remained stable from generations 10 to 17 and the equimultiple random matching pedigrees conservation population conservation effect of Langshan chicken was effective as measured by these criteria.

Polymorphisms and their Haplotype Combinations in the Lysozyme Gene Associated with the Production Traits of a Chinese Native Chicken Breed

ABSTRACT Animal lysozymes, which have been studied in many of invertebrate and vertebrate species, have been characterized and demonstrated to be immune-associated molecules, digestive enzymes and multifunctional molecules. The purpose of this study was to detect the connection between lysozyme-gene polymorphism and the production traits of a Chinese native chicken breed (Langshan chicken). Four single nucleotide mutation sites were identified: G345A, C1726T, G1836A, A1838G. By the linkage disequilibrium analysis, six haplotypes and 15haplotype combinations were depicted in the studied population. The statistical analysis demonstrated that the SNPs and the haplotype combinations are related to body weight at sixteen weeks of age in Langshan chickens (p<0.05), and those with combined haplotype Hap3-Hap6 (GA-TT-GG-AA) presented higher body weight. Our study demonstrated that the SNPs and their haplotype combinations in the lysozyme gene were associated with the chicken production traits, and that SNPs can be used as a molecular marker for chicken marker-assisted selection.

Exploring the genetic variants of insulin-like growth factor II gene and their associations with two production traits in Langshan chicken

ABSTRACTInsulin-like growth factor II (IGF-II) is one of the members of the somatotropic axis which controls the growth and development of animals. This study was conducted to identify single-nucleotide polymorphisms in the IGF2 gene and study their associations with two production traits in a Chinese indigenous chicken (Langshan chicken) population. Genetic variants within the IGF2 gene were screened through PCR-SSCP and DNA sequencing methods. A C6707G mutation (Chromosome 5 position 13,161,038 build 4) was identified. Associations between the mutations of the gene with two production traits were analysed. The results showed that individuals within the GG genotype had significantly higher 16-week-old body weight than those within the CG genotype. In addition, the GG individuals also had significantly higher 300 days egg numbers than individuals within CC or CG genotype. Ratios of dominance effects to absolute values of additive effects were less than 0 for both traits implying that Langshan chickens with homozygous genotypes for this locus had higher performance than individuals with heterozygous genotypes.

Characterization of Akirin 2 gene in Langshan chicken

Akirin play an important role not only in innate immune response but also in skeletal myogenesis. The chicken’s Akirin gene family only has Akirin 2. We detected the coding sequences of the Akirin 2 gene in a Chinese indigenous chicken (Langshan chicken) population to investigate the possibility of using this gene for chicken marker-assisted selection. The results of PCR-SSCP and DNA sequence showed that there were no polymorphisms in the six amplified regions of the Akirin 2 gene. In addition, there was no SNP record about the chicken’s Akirin 2 gene by searching in NCBI. Thus, the Akirin 2 gene may not be suitable to be used in chicken as a gene marker for marker- assisted selection.

Effects of single and combined genotypes of MC4R and POU1F1 genes on two production traits in Langshan chicken

The objective of this study was to analyze the effects of single and combined genotypes of MC4R and POU1F1 genes in Chinese well-known indigenous chicken (Langshan chicken) population. Genetic variants within MC4R gene and POU1F1 gene were screened through PCR-SSCP and DNA sequencing methods. A C/T mutation at nt 944 in MC4R gene (NC_006089.2:g. 944C>T) and a G/A mutation at nt 3109 in POU1F1 gene (NC_006088.2:g. 3109 G>A) were identified. Associations between the mutations of the two genes with two production traits were analyzed. The results showed that, at MC4R locus, individuals with BB and AB genotypes had highly significantly higher body weight at 16 weeks (p < 0.01) than did those with the AA genotype. And, individuals within AA and AB genotypes had significantly higher egg numbers at 300 days (p < 0.05). At POU1F1 locus, individuals with CD genotype had higher body weight at 16 weeks and egg numbers at 300 days (p < 0.05). Furthermore, combined genotypes from these two loci were found to be associated with egg numbers at 300 days (p < 0.05). The individuals within combined genotype AB/CD had higher egg production. Therefore, variations identified within the MC4R and POU1F1genes are suitable for future use in identifying chickens with the genetic potential of higher body weight and reproductive traits, at least in the population of Langshan chickens.

Establishment and biological characterization of fibroblast cell line from the Langshan chicken

We needed to establish an embryonic fibroblast cell line from the Langshan chicken (LSCEF61) to preserve their important genetic resources at the cellular level. The cell line was established from 9-day-old embryos by direct explant culture and cryopreservation techniques. Cell morphology, dynamic proliferation and any contamination present were tested, and the karyotype and levels of isoenzymes of lactic dehydrogenase and malic dehydrogenase were analysed. Four types of fluorescent protein exogenous genes for pEGFP-C(1), pEGFP-N(3), pEYFP-N(1) and pDsRed1-N(1) were transfected into the cells. Showed that the cells were healthy and were of spindle shaped structure, without change in morphology. Cell growth curves were of typical S-shape. Assays for microbial contamination were negative. The LSCEF61 line showed no cross-contamination when assessed by isoenzyme analysis. Chromosome number (2n) = 78 on more than 90% of occasions. The four types of fluorescent protein extro-genes appeared to be expressed effectively with high transfection efficiency between 15.6% and 38.6%. The cell line met each of the quality control standards required for the American Type Culture Collection. It had not only preserved the genetic resources of the important Langshan chicken at the cellular level, but also provided valuable material for genomic, post-genomic and somatic cell cloning research and other applications.

Maternal low-protein diet programmes offspring growth in association with alterations in yolk leptin deposition and gene expression in yolk-sac membrane, hypothalamus and muscle of developing Langshan chicken embryos

The present study was aimed to investigate the mechanism underlying the influence of maternal low-protein (LP) diet on offspring growth in the chicken. One hundred and twenty Chinese inbred Langshan breeder hens were allocated randomly into two groups fed diets containing low (10%, LP) or normal (15%) crude protein levels. Low dietary protein did not affect the body weight of hens, but significantly decreased the laying rate and egg weight. The yolk leptin content was significantly lower in eggs laid by LP hens, while no differences were detected for yolk contents of corticosterone, tri-iodothyronine (T3) or thyroxine. Despite significantly lower hatch weight, the LP offspring demonstrated obviously higher serum T3 concentration, which is in accordance with the faster post-hatch growth rate achieving significantly heavier body weight and pectoralis major muscle weight 4 weeks post-hatching. Expression of 20-hydroxysteroid dehydrogenase (20-HSD) mRNA in the yolk-sac membrane was significantly down-regulated at embryonic day 14, whereas that of transthyretin and leptin receptor (LepR) was not altered. Moreover, hypothalamic expression of 20-HSD, glucocorticoid receptors, thyrotropin-releasing hormone and LepR mRNA was significantly up-regulated in the LP group compared with their control counterparts. In the pectoralis major muscle, significantly higher expression of insulin-like growth factor (IGF)-I and IGF-I receptor mRNA was observed in LP embryos. The present study provides evidence that maternal LP diet programmes post-hatch growth of the offspring. The associated alterations in yolk leptin deposition as well as in yolk-sac membrane, fetal hypothalamus and muscle gene expression may be involved in mediating such programming effect in the chicken.

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 subspecies (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.

Evaluation of genetic diversity in Chinese indigenous chicken breeds using microsatellite markers

China is rich in chicken genetic resources, and many indigenous breeds can be found throughout the country. Due to poor productive ability, some of them are threatened by the commercial varieties from domestic and foreign breeding companies. In a large-scale investigation into the current status of Chinese poultry genetic resources, 78 indigenous chicken breeds were surveyed and their blood samples collected. The genomes of these chickens were screened using microsatellite analysis. A total of 2740 individuals were genotyped for 27 microsatellite markers on 13 chromosomes. The number of alleles of the 27 markers ranged from 6 to 51 per locus with a mean of 18.74. Heterozygosity (H) values of the 78 chicken breeds were all more than 0.5. The average H value (0.622) and polymorphism information content (PIC, 0.573) of these breeds suggested that the Chinese indigenous chickens possessed more genetic diversity than that reported in many other countries. The fixation coefficients of subpopulations within the total population (F(ST)) for the 27 loci varied from 0.065 (LEI0166) to 0.209 (MCW0078), with a mean of 0.106. For all detected microsatellite loci, only one (LEI0194) deviated from Hardy-Weinberg equilibrium (HWE) across all the populations. As genetic drift or non-random mating can occur in small populations, breeds kept on conservation farms such a Langshan chicken generally had lower H values, while those kept on large populations within conservation regions possessed higher polymorphisms. The high genetic diversity in Chinese indigenous breeds is in agreement with great phenotypic variation of these breeds. Using Nei's genetic distance and the Neighbor-Joining method, the indigenous Chinese chickens were classified into six categories that were generally consistent with their geographic distributions. The molecular information of genetic diversity will play an important role in conservation, supervision, and utilization of the chicken resources.

Cluster Analysis of 12 Chinese Native Chicken Populations Using Microsatellite Markers

The genomes of Chinese native chicken populations were screened using microsatellites as molecular markers. A total of, 528 individuals comprisede12 Chinese native chicken populations were typed for 7 microsatellite markers covering 5 linkage groups and genetic variations and genetic distances were also determined. In the 7 microsatellite loci, the number of alleles ranged from 2 to 7 per locus and the mean number of alleles was 4.6 per locus. By using fuzzy cluster, 12 Chinese native chicken populations were divided into three clusters. The first cluster comprised Taihe Silkies, Henan Game Chicken, Langshan Chicken, Dagu Chicken, Xiaoshan Chicken, Beijing Fatty Chicken and Luyuan Chicken. The second cluster included Chahua Chicken, Tibetan Chicken, Xianju Chicken and Baier Chicken. Gushi Chicken formed a separate cluster and demonstrated a long distance when comparing with other chicken populations. (Asian-Aust. J. Anim. Sci. 2004. Vol 17, No. 8 : 1047-1052)