Deqian Wang

Comparative proteomic analysis of the hepatic response to heat stress in Muscovy and Pekin ducks: insight into thermal tolerance related to energy metabolism.

The Pekin duck, bred from the mallard (Anas platyrhynchos) in china, is one of the most famous meat duck species in the world. However, it is more sensitive to heat stress than Muscovy duck, which is believed to have originated in South America. With temperature raising, mortality, laying performance, and meat quality of the Pekin duck are severely affected. This study aims to uncover the temperature-dependent proteins of two duck species using comparative proteomic approach. Duck was cultured under 39°C ± 0.5°C for 1 h, and then immediately returned to 20°C for a 3 h recovery period, the liver proteins were extracted and electrophoresed in two-dimensional mode. After analysis of gel images, 61 differentially expressed proteins were detected, 54 were clearly identified by MALDI TOF/TOF MS. Of the 54 differentially expressed protein spots identified, 7 were found in both species, whereas 47 were species specific (25 in Muscovy duck and 22 in Pekin duck). As is well known, chaperone proteins, such as heat shock protein (HSP) 70 and HSP10, were abundantly up-regulated in both species in response to heat stress. However, we also found that several proteins, such as α-enolase, and S-adenosylmethionine synthetase, showed different expression patterns in the 2 duck species. The enriched biological processes were grouped into 3 main categories according to gene ontology analysis: cell death and apoptosis (20.93%), amino acid metabolism (13.95%) and oxidation reduction (20.93%). The mRNA levels of several differentially expressed protein were investigated by real-time RT-PCR. To our knowledge, this study is the first to provide insights into the differential expression of proteins following heat stress in ducks and enables better understanding of possible heat stress response mechanisms in animals.

Effect of dietary fatty acids on serum parameters, fatty acid compositions, and liver histology in Shaoxing laying ducks.

The effects of different fatty acid (FA) contents in diet on serum parameters, FA compositions of eggs and meat, and liver morphological changes were studied in Shaoxing laying ducks. A total of 264 ducks at 17 weeks were fed a control diet or a diet containing 30 g/kg fish oil (FO), 25 g/kg sunflower oil (SO), or 30 g/kg palm oil with 20 g/kg beef tallow (PBO). Malondialdehyde (MDA) content in the liver and the serum of ducks fed the PBO diet was significantly (P<0.05) higher than that of ducks fed the other diets. Triglyceride (TG) and total cholesterol (TC) levels were significantly lower (P<0.05) in ducks fed the FO diet. Serum TC also was lower in ducks fed the SO diet. Superoxide dismutase (SOD) activity was also affected by diets. The contents of polyunsaturated FAs (PUFAs) in eggs and meat were significantly higher (P<0.001) in ducks fed the FO and SO diets than in ducks fed the control diet. The level of C22:6 (n-3) FA in ducks fed the FO diet was significantly higher than that in ducks fed the other diets. However, the conversion efficiency of the longer-chain C20:5 (n-3) FA was higher than that of C22:6 (n-3). Ducks fed the PBO diet exhibited lipid droplet accumulation in the liver. These results demonstrate that a diet enriched with different FAs has strong effects on serum lipid levels and the deposition of PUFAs into tissue lipids.

Paternity assessment: application on estimation of breeding value in body-weight at first egg trait of egg-laying duck (Anas platyrhynchos)

Paternity index was analyzed using five microsatellite loci among Chinese egg-laying ducks (Anas platyrhynchos). Based on the paternity relationship that was identified by paternity index analysis, the estimated breeding value (EBV) was calculated using BLUP (best linear unbiased predictor) method. Body weight at first egg (BWF) is the only considered trait in this study. In total, 12 sires, 31 dams and 77 daughters were involved in the EBV calculation. The results demonstrated that five microsatellite loci’s polymorphism information content (PIC) ranged from 0.795 in locus AY493338 to 0.957 in locus AY493264 with average 0.899; the parent–offspring relationships were built by these microsatellites’ genotype, 12 families of half sibling and 2 families of full sibling were involved, and the relationship error is smaller than 10−7. The EBV results suggest that the average EBV was significantly higher in females (average EBV is 10.234 and 0.1045 for mother and daughter, respectively) than males (average EBV is just −26.44). The EBV results on BWF were in good agreement with the principle of GH (growth hormone) expression in poultry. These results show that paternity analyses of Chinese egg-laying ducks were basically resolved using the five microsatellite loci selected. The paternity relationships can apply in Chinese egg-laying duck breeding to quicken the improvement of genetic progress.

Assignment of CCR7 gene to chicken chromosome 27 by radiation hybrid panel mapping.

The protein encoded by CC chemokine receptor 7 (CCR7) is a member of the G protein-coupled receptor family. This receptor was identified as a gene induced by the Epstein-Barr virus (EBV), and is thought to be a mediator of EBV effects on B lymphocytes. This receptor is expressed in various lymphoid tissues and activates B and T lymphocytes. It has been shown to control the migration of memory T cells to inflamed tissues, as well as stimulate dendritic cell maturation. To map the CCR7 gene in chicken chromosome, a 6000 rads chicken-hamster radiation hybrid panel (ChickRH6) was used. PCR of samples from ChickRH6 revealed that the location of CCR7 gene is linked to the maker SEQ0347 (6 cR away) with LOD score of 16.6 and that the marker SEQ0347 is located on chromosome 27 at 27 cR of RH (radiation hydrid) map. We compared the corresponding human mRNA sequence with the predicted coding sequence of chicken CCR7 gene, and found that the assembled contig shared a high percentage of similarity with that of the human gene.

Sequence analysis of a putative goose RIG-I gene

Li, G., Li, J., Tian, Y., Wang, DE., Shen, J., Tao, Z., Xu, J. and Lu, L. 2012. Sequence analysis of a putative goose RIG-I gene. Can. J. Anim. Sci. 92: 143-151. Retinoid acid-inducible gene-I (RIG-I) is a critical cytoplasmic RNA sensor which plays an important role in the recognition of, and response to, influenza virus and other RNA viruses. In the present study, A 3808-bp cDNA encoding goose RIG-I (goRIG-I) was cloned from splenic lymphocytes of geese using RT-PCR and rapid amplification of cDNA ends (RACE) techniques. The encoded protein, which is predicted to consist of 933 amino acids, has a molecular weight of 106.4 kDa and includes an N-terminal caspase recruitment domain (CARD), a domain with the signature of DExD/H box helicase (helicase domain), and a C-terminal repression domain (RD) similar to duck RIG-I (duRIG-I), human RIG-I, and mouse RIG-I. The goRIG-I showed 93.8 and 78.0% amino acid sequence identity with previously described duRIG-I and finch RIG-I, respectively, and 48.9-53.0% sequence identity with mammalian homologs. Quantitative RT-PCR analysis indicated that the goRIG-I gene is strongly expressed in the liver, lung, brain, spleen, and bursa of Fabricius. These findings lay the foundation for further research on the function and mechanism of avian RIG-I in innate immunity.

Molecular cloning, characterization and expression patterns of heat shock protein 60 (HSP60) in the laying duck (Anas platyrhynchos)

Wang, D., Lu, L., Tian, Y., Li, J., Shen, J., Tao, Z., Li, G. and Xu, N. 2012. Molecular cloning, characterization and expression patterns of heat shock protein 60 (HSP60) in the laying duck (Anas platyrhynchos). Can. J. Anim. Sci. 92: 425-432. In the present study, we cloned and characterized the HSP60 cDNA from Anas platyrhyncho (designated as ApHSP60) using a combination of homology and rapid amplification of cDNA ends (RACE). The full-length of ApHSP60 is 2027 bp in length, with an open reading frame of 1707 bp encoding a putative protein of 569 amino acids. Comparison of amino acid sequences of HSP60 revealed ApHSP60 is highly conserved, especially in the domains of classical HSP60 family signatures. ApHSP60 transcripts were at low expression levels throughout embryo development. ApHSP60 transcripts were constitutively expressed in all tested tissues of untreated laying duck, with a maximum level in the liver. Fluorescent real-time quantitative reverse transcription-polymerase chain reaction was applied to determine ApHSP60 expression after exposure to different thermal shocks. Under long term treatment with both 30°C and 35°C, ApHSP60 transcripts in heart and liver were significantly up-regulated. Otherwise, ApHSP60 transcripts were remarkably down-regulated in heart and liver under acute challenge with 40°C (a fatal temperature for laying duck). A time-dependent expression pattern of ApHSP60 was found in the recovery period after heat shock reaction. ApHSP60 expression levels in liver and heart were immediately up-regulated to the maximum at 1 h post-challenge, and then decreased to pre-challenge levels by 2 h and 3 h post-challenge, respectively. These results suggest that mRNA expression of the ApHSP60 gene is constitutive and inducible. Meanwhile, it plays an important role in response to heat stressors.

Evaluation of the genetic diversity and population structure of five indigenous and one introduced Chinese goose breeds using microsatellite markers

Li, J., Yuan, Q., Shen, J., Tao, Z., Li, G., Tian, Y., Wang, D., Chen, L. and Lu, L. 2012. Evaluation of the genetic diversity and population structure of five indigenous and one introduced Chinese goose breeds using microsatellite markers. Can. J. Anim. Sci. 92: 417-423. The aim of this study was to determine the genetic diversity and evolutionary relationships among five indigenous Chinese goose breeds and one introduced goose breed using 29 microsatellite markers. A total of 334 distinct alleles were observed across the six breeds, and 45 of the 334 alleles (13.5%) were unique to only one breed. The indigenous geese showed higher diversity in terms of the observed number of alleles per locus (4.48-5.90) and observed heterozygosity (0.46-0.53) compared with the introduced breed (3.97 and 0.29, respectively). The pairwise genetic differentiation (FST) between the six goose breeds ranged from 0.04 between Panshi Grey goose (PS) and Yongkang Grey goose to 0.47 between PS and Landes goose; similarly, Neis genetic distance varied between 0.25 and 0.75. However, the FST between the indigenous Chinese goose breeds was very small. In addition, genetic distance estimate, phylogenic, and cluster analyses of the genetic relationships and population structure revealed that some indigenous goose breeds had hybridized more frequently, resulting in a loss of genetic distinctiveness.

A Study on the Development Path of China's Low-Carbon Economy under the Global Climate Change

Global warming has been a serious threat to the sustainable development of human society. Reducing the large-scale emissions of greenhouse gases in the process of economic development and developing low-carbon economy have become necessary requirements for the national economic and social sustainable development. In this paper, combining the status quo of Chinas economic development with the example of a city in northern China, the pathway of low-carbon economy development and the feasibility of its implementation were discussed. The analytical results show that there is a great difference in cost-benefit aspects in industries with different low-carbon paths for the economic development. That is to say, the Development of Chinas Low-Carbon Economy cannot be achieved by the market mechanism alone, which needs the government to support in full force.

Mapping and expression analysis of chicken NDRG1 and NDRG3 genes.

N-myc downstream-regulated genes 1 and 3 (NDRG1 and NDRG3) are members of the alpha/beta hydrolase superfamily. Phylogenetic analysis of the family demonstrated that human NDRG1 and 3 belong to a subfamily. The mapping and gene expression patterns of these genes represent one step toward further investigation into their possible roles in the chicken (Gallus gallus). To map these genes in the chicken chromosome, a 6000 rads chicken-hamster radiation hybrid panel (ChickRH6) was used. Primers were designed according to the published human sequences for amplification of those two genes. We compared the corresponding human mRNA sequences with the predicted coding sequences of the chicken NDRG1 and 3 genes and found that the assembled contigs shared a high percentage of similarity with the human genes. PCR of samples from ChickRH6 revealed that the locations of NDRG1 and 3 are linked to the markers MYC (58 cRs away, LOD score 4.52) and SEQ0265 (10 cRs away, LOD score 17.81), respectively. This result adds two new markers to the chicken RH map, and it reinforces that the RH technique is indeed a powerful tool for mapping genes due to its rapidity, precision, convenience, and reproducibility. In addition, we detected the gene expression and distribution of chicken NDRG1 and 3 in seven tissues, including heart, liver, spleen, lung, muscle, brain, and thymus, by RT-PCR, and found that NDRG1 is relatively ubiquitously expressed in all the tested tissues and highly expressed in heart and liver, whereas NDRG3 is high in heart, muscle, and brain.

Application of comparative genomics in chicken gene mapping

Abstract The NDRG4 gene is a member of the N‐myc downregulated gene family which belongs to the alpha/beta hydrolase superfamily. The protein encoded by this gene is a cytoplasmic protein that may be involved in the regulation of mitogenic signalling in vascular smooth muscle cells. To map this gene in the chicken chromosome, a 6000 rads chicken‐hamster radiation hybrid panel (ChickRh6) was used. primers were designed according to the published human sequence for amplification of the chicken NDRG4 gene by comparative genomics. We compared the corresponding human mRNa sequence with the predicted coding sequence of the chicken NDRG4 gene, and found that the assembled contig shared a high percentage of similarity with that of the human gene. PCR of samples from the ChickRh6 revealed the locations of the NDRG4 gene to be linked to the marker PARD6G (5 cR away) with a LOD score of 20.46. Our present results support the idea that the RH technique is indeed a powerful tool for mapping genes due to its rapidity, precision, convenience and reproducibility.