Black-bone Silky Fowl Research Articles

Integrating Genomics and Transcriptomics to Identify Candidate Genes for Egg Production in Taihe Black-Bone Silky Fowls (Gallus gallus domesticus Brisson).

The Taihe Black-Bone Silky Fowl (Gallus gallus domesticus Brisson) possesses significant value in terms of consumption, medicinal applications, and ornamental appeal, representing a precious genetic resource and traditional Chinese medicinal material. However, considerable variation exists within populations regarding egg-laying performance. This study integrates a whole-genome selection signal analysis (SSA) with a transcriptome analysis to identify genes associated with egg-laying traits in Taihe Black-Bone Silky Fowls. We identified 31 candidate genes under selection from the high-yield chicken (HC) and low-yield chicken (LC) groups. Additionally, through RNA-seq analysis, 257 common differentially expressed genes (DEGs) were identified from four comparative groups. Two overlapping genes-LPL and SETBP1-were found in both the selected gene and DEG lists. These selected genes and DEGs were enriched in pathways related to ovarian development, including the lysosome pathway, the ECM-receptor interaction pathway, the TGF-beta signaling pathway, the Wnt signaling pathway, the PPAR signaling pathway, and the glycerolipid metabolism pathway. These research findings contribute to the breeding of Taihe Black-Bone Silky Fowls with high egg production traits and provide a theoretical foundation for exploring the regulatory mechanisms of avian reproduction.

Integrated transcriptome and proteome analysis reveals the unique molecular features and nutritional components on the muscles in Chinese Taihe black-bone silky fowl chicken.

The Taihe Black-Bone silky fowl chicken (BB-sfc) is a renowned dietary and medicinal chicken globally recognized for its high nutritional and medicinal value. Compared to the local Black-Bone black-feathered chicken (BB-bfc), the Taihe silky fowl chicken has higher levels of amino acids, trace elements, and unsaturated fatty acids in their muscles, which offer anti-aging, anti-cancer, and immune enhancing benefits. Despite this, the unique nutritional components, genes, and proteins in Taihe silky fowl chicken muscles are largely unknown. Therefore, we performed a comprehensive transcriptome and proteome analysis of muscle development between BB-sfc and BB-bfc chickens using RNA-Seq and TMT-based quantitative proteomics methods. RNA-Seq analysis identified 286 up-regulated genes and 190 down-regulated genes in BB-sfc chickens, with oxidoreductase activity and electron transfer activity enriched in up-regulated genes, and phospholipid homeostasis and cholesterol transporter activity enriched in down-regulated genes. Proteome analysis revealed 186 significantly increased and 287 significantly decreased proteins in Taihe BB-sfc chicken muscles, primarily affecting mitochondrial function and oxidative phosphorylation, crucial for enhancing muscle antioxidant capacity. Integrated transcriptome and proteome analysis identified 6 overlapped up-regulated genes and 8 overlapped down-regulated genes in Taihe silky fowl chicken, related to improved muscle antioxidant status. Taken together, this research provides a comprehensive database of gene expression and protein information in Taihe Black-Bone silky fowl chicken muscles, aiding in fully exploring their unique economic value in the future.

Transcriptomic and metabolomic analyses of the ovaries of Taihe black-bone silky fowls at the peak egg-laying and nesting period.

The poor reproductive performance of most local Chinese chickens limits the economic benefits and output of related enterprises. As an excellent local breed in China, Taihe black-bone silky fowl is in urgent need of our development and utilization. In this study, we performed transcriptomic and metabolomic analyses of the ovaries of Taihe black-bone silky fowls at the peak egg-laying period (PP) and nesting period (NP) to reveal the molecular mechanisms affecting reproductive performance. In the transcriptome, we identified five key differentially expressed genes (DEGs) that may affect the reproductive performance of Taihe black-bone silky fowl: BCHE, CCL5, SMOC1, CYTL1, and SCIN, as well as three important pathways: the extracellular region, Neuroactive ligand-receptor interaction and Cytokine-cytokine receptor interaction. In the metabolome, we predicted three important ovarian significantly differential metabolites (SDMs): LPC 20:4, Bisphenol A, and Cortisol. By integration analysis of transcriptome and metabolome, we identified three important metabolite-gene pairs: "LPC 20:4-BCHE", "Bisphenol A-SMOC1", and "Cortisol- SCIN". In summary, this study contributes to a deeper understanding of the regulatory mechanism of egg production in Taihe black-bone silky fowl and provides a scientific basis for improving the reproductive performance of Chinese local chickens.

Transcriptome Analysis of the Ovaries of Taihe Black-Bone Silky Fowls at Different Egg-Laying Stages.

The poor egg-laying performance and short peak egg-laying period restrict the economic benefits of enterprises relating to the Taihe black-bone silky fowl. Ovaries are the main organ for egg production in poultry. Unlike that of mammals, the spawning mechanism of poultry has rarely been reported. As a prominent local breed in China, the reproductive performance of Taihe black-bone silky fowls is in urgent need of development and exploitation. To further explore the egg-laying regulation mechanism in the different periods of Taihe black-bone silky fowls, the ovarian tissues from 12 chickens were randomly selected for transcriptome analysis, and 4 chickens in each of the three periods (i.e., the pre-laying period (102 days old, Pre), peak laying period (203 days old, Peak), and late laying period (394 days old, Late)). A total of 12 gene libraries were constructed, and a total of 9897 differential expression genes (DEGs) were identified from three comparisons; the late vs. peak stage had 509 DEGs, the pre vs. late stage had 5467 DEGs, and the pre vs. peak stage had 3921 DEGs (pre-stage: pre-egg-laying period (102 days old), peak-stage: peak egg-laying period (203 days old), and late-stage: late egg-laying period (394 days old)). In each of the two comparisons, 174, 84, and 2752 differentially co-expressed genes were obtained, respectively, and 43 differentially co-expressed genes were obtained in the three comparisons. Through the analysis of the differential genes, we identified some important genes and pathways that would affect reproductive performance and ovarian development. The differential genes were LPAR3, AvBD1, SMOC1, IGFBP1, ADCY8, GDF9, PTK2B, PGR, and CD44, and the important signaling pathways included proteolysis, extracellular matrices, vascular smooth muscle contraction, the NOD-like receptor signaling pathway and the phagosome. Through the analysis of the FPKM (Fragments Per Kilobase of exon model per Million mapped fragments) values of the genes, we screened three peak egg-laying period-specific expressed genes: IHH, INHA, and CYP19A1. The twelve genes and five signaling pathways mentioned above have rarely been reported in poultry ovary studies, and our study provides a scientific basis for the improvement of the reproductive performance in Taihe black-bone silky fowls.

In vitro immunomodulatory and antioxidant effects of oligopeptides and four characteristic peptides in black-bone silky fowl (Gallus gallus domesticus Brisson).

Black-bone silky fowl (Gallus gallus domesticus Brisson) is considered to have strengthening effect on the body and immunomodulatory effects. The black-bone silky fowl peptide (BSFP) was produced by enzymatic digestion of the whole black-bone silky fowl (including the head and claws) after removal of the viscera. Afterwards, the four of the characteristic peptides Glu-Phe (EF), Glu-Glu-Leu (EEL), Glu-His-Pro-Thr (EHPT), Ala-Gly-Gly-His (AGGF) of the BSFP were identified by HPLC-MS/MS. The preventive effects of BSFP and the four characteristic peptides on antioxidant and immunomodulation were investigated. The antioxidant capacity was assessed by in vitro HepG2 intracellular reactive oxygen species (ROS). The immunomodulatory experiments were conducted by measuring the effects of the BSFP and four peptides on the proliferation of splenocytes, T and B lymphocytes cells, the CD4+ /CD8+ T lymphocytes ratio, and the phagocytic capacity of macrophages and the nitric oxide (NO) content of macrophages. The four peptides of BSFP showed strong antioxidant capacity, with the most potent peptide for intracellular ROS being AGGF, with 56% inhibition. AGGF, EF, and BSFP showed highly positive effects on splenocyte proliferation and when Concanavalin A (ConA) was used as a stimulus for T lymphocytes and lipopolysaccharide (LPS) as a stimulus for B lymphocytes, the peptides stimulated cell proliferation in a dose-dependent manner. Of these, EF, AGGF, and BSFP promoted the proliferation of T lymphocytes; EF, EHPT, and BSFP significantly promoted the proliferation of B lymphocytes. EHPT and BSFP increased the CD4+ /CD8+ ratio of T cells. Needle aspiration of neutral red was significantly promoted by macrophages treated with peptides other than EF. In addition, EEL, EHPT, AGGF, and BSFP had a promotive effect on NO production in phagocytes. The results indicate that BSFP is a peptide product with good immunomodulatory functions, four peptides identified from BSFP show outstanding effects in terms of antioxidant properties and immunomodulation. PRACTICAL APPLICATIONS: In this study, the amino acid composition and relative molecular masses of the black-bone silky fowl peptide were analyzed, while the four peptides with significant effects on antioxidant and immunomodulatory properties in black-bone silky fowl peptide were identified by HPLC-MS/MS technique. Positive effects of black-bone silky fowl peptide and its four peptides on antioxidant capacity and immunomodulatory ability as revealed by cell experiments. The results of this experiment provide a preliminary theoretical basis for the development of new functional foods using black-bone silky fowl peptide and their characteristic peptides.

Comparative Metabolomics Analysis Reveals the Unique Nutritional Characteristics of Breed and Feed on Muscles in Chinese Taihe Black-Bone Silky Fowl.

The Chinese Taihe Black-bone silky fowl (TBsf) is the homology of medicine and food and has high nutritional and medical value all over the world. However, the nutritional compositions and potential metabolite biomarkers of Taihe silky fowl in muscles are still poorly understood. In this study, we investigated the differences in nutritional components between TBsf and another similar breed (Black Feathered chicken and laid green-shelled eggs, BF-gsc). Meanwhile, we also explored the divergences in muscle characteristics of Taihe silky fowl fed with two different diets; that is, normal chicken feed (TBsf-ncf) and Broussonetia papyrifera-fermented feed (TBsf-bpf). Firstly, the growth performance and biochemical index of Taihe silky fowl was significantly different compared with black-feathered chicken. Secondly, we identified the metabolic alterations in Taihe silky fowl by performing an un-targeted UHPLC-Q-TOF-MS/MS analysis. Our results suggested that all the metabonomic characteristics had obvious separation between TBsf-ncf, TBsf-bpf and BF-gsc groups, both in the positive and negative ion mode by PCA analysis. Next, OPLS-DA multivariate analysis revealed that 57 metabolites (in positive mode) and 49 metabolites (in negative mode) were identified as differential metabolites between the TBsf-ncf and BF-gsc groups. These differential metabolites were mainly enriched to ABC transporters, biosynthesis of amino acids and aminoacyl-tRNA biosynthesis. Besides, 47 metabolites (in positive) and 13 metabolites (in negative) were differentially regulated between the TBsf-ncf and TBsf-bpf groups, which were majorly involved in histidine metabolism and linoleic metabolism. Furthermore, the integrated network analysis suggested that DL-arginine, DL-isoleucine, linoleoylcarnitine, stearoylcarnitine (positive) and ricionleic acid, D-proline, and uric acid (negative) were the significant metabolic biomarkers in Taihe silky fowl. Moreover, the metabolites of primaquine, ticlpoidine, riboflavin, acetylcarnitine (positive) and salicylic acid, acetaminophen sulfate, and glutamic acid (negative) were markedly changed in the Taihe silky fowl fed with BP-fermented feed. In summary, a global survey of the nutritional components and metabolite differences was performed in muscle tissues of Taihe silky fowl between various breeds and feeds. Meanwhile, our study provided valuable information for nutritional components and metabolic biomarkers in Chinese Taihe silky fowl, which greatly promoted the economic value of the black-boned chicken industry and laid a solid theoretical foundation for the development of chicken products with greater added value in future.

Review of genetic diversity and breed identification of black-bone silky fowl

Black-bone silky fowl, sweet, pungent, and hot-natured, is one of the valuable domesticated birds with special economic value in China's genebank of poultry breed, which has a long history of medicinal and edible uses. It has the effects of tonifying liver and kidney, replenishing Qi and blood, nourishing yin, clearing heat, regulating menstruation, invigorating spleen, and securing essence. Therefore, it has remarkable efficacy of enhancing physical strength, tonifying blood, and treating diabetes and gynecological diseases. Various local black-bone silky fowl breeds have been generated due to the differences in environmental conditions, breed selection, and rearing conditions in different areas of China, which are mainly concentrated in Taihe, Wan'an, and Ji'an in Jiangxi province and Putian, Jinjiang, and Yongchun in Fujian province. The indigenous chicken breeds in China have different body sizes, appearance, coat colors, etc. The complex lineages lead to extremely unstable genetic traits. The diverse breeds similar in appearance result in the confusion in the market of silky fowl breeds. With the rapid development of molecular biological technology, the genetics of black-bone silky fowls has been intensively studied. This article reviews the research progress of the germplasm resources, genetic diversity, and breed identification of black-bone silky fowl in China at the morphology, chromosome, protein, and DNA levels. Further, it introduces the principles, application status, and limitations of DNA markers such as mitochondrial DNA, microsatellite markers, and SNPs. This review provides a theoretical basis for the mining of elite trait genes and the protection and utilization of local black-bone silky fowl germplasm resources in China.

Residue depletion of sarafloxacin in black-bone silky fowl tissues after oral administration

In this study, the residue depletion of sarafloxacin in black-bone silky fowl (BSF) was studied after oral doses of sarafloxacin (10 mg/kg BW for 7 consecutive days). Muscle and liver tissues were collected at differentwithdrawal periods and determined by HPLC-MS/ MS method. The limit of detection for sarafloxacin was 1.0 μg/kg, and the recoveries from blank fortified samples were 93.53%~108.47% with coefficients of variation less than 9.28%. At first day after ending sarafloxacin treatment, the mean concentrations of sarafloxacin in muscle and liver were 366.88 ± 129.51 and 120.35 ± 46.86 μg/kg, respectively, higher than their maximum residue limits (10 μg/kg for muscle, 80 μg/kg for liver). Notably, the sarafloxacin concentrations in muscle depleted very slowlyand were still up to 45.46 ± 12.94 μg/ kg at 43.25 days after the last administration. Interestingly, the sarafloxacin concentrations in both tissues increased into peak values at 21 days. In addition, the withdrawal time of sarafloxacinin BSFs should be 93 days as calculated in this study, significantly longer than that (0 day) in common broiler chickens. Therefore, our study provides data for a more prudent use of sarafloxacin in BSFs and suggests a withdrawal time of 93 days was necessary to guarantee safety in BSFs for the consumers.

Proteomic study of Chinese black-bone silky fowl and the ring-necked pheasant egg white by iTRAQ technique

Eggs are the best protein supplements for human beings, which have high nutritional value and are rich in all kinds of essential amino acids. Wild eggs are produced by some rare poultry, considered to have higher nutritional value than ordinary eggs. In this study, black-bone chicken and ring-necked pheasant eggs were selected as samples. Isobaric tags for the relative and absolute quantification labelling techniques (iTRAQ) were used to analyze the protein difference between the two samples. A total of 205 proteins were identified, of which 87 were significantly different. Among those differential proteins, 37 were significantly up-regulated while 50 were significantly down-regulated. Gene ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis showed that these differentially expressed proteins were closely related to cholesterol metabolism. The expression of some proteins that are adverse to cholesterol metabolism was significantly down-regulated in black bone chickens, such as Apolipoprotein B, Apovitellenin-1, Vitellogenin-1 and Vitellogenin-2. Protein interaction analysis showed that there were strong interactions among these proteins. These results indicated that compared with ring-necked pheasant, black-bone chicken eggs have a stronger ability to metabolize cholesterol and are less likely to cause the increase of plasma cholesterol.

Pharmacokinetics of Ceftiofur Sodium in Black-bone Silky Fowl after One Single Intravenous and Intramuscular Injection

Background: Ceftiofur is a third-generation cephalosporin antibiotic developed exclusively for veterinary applications. Although not approved in China, ceftiofur is being used extensively in an extra-label manner to treat poultry infections. Black-bone silky fowl is a unique chicken breed which is different from the common chicken breeds in both morphology and other physiology. These differences may result in varied pharmacokinetic profiles. Therefore, the present study aimed to investigate the pharmacokinetics of ceftiofur (measured by ceftiofur and its active metabolites concentrations) in black-bone silky fowl following a single intravenous or intramuscular injection of ceftiofur sodium.Methods: Ceftiofur sodium was intravenously and intramuscularly given to six healthy black-bone silky fowl at the dose of 10 mg/kg body weight. A derivatization method was used to quantify the concentrations of ceftiofur and its active metabolites (expressed as desfuroylceftiofur acetamide) in plasma samples. A non-compartmental method was used to calculate the pharmacokinetics parameters. Results: The terminal half-life (t1/2lz) was calculated as 3.19±0.28 and 3.36±0.17 h following intravenous and intramuscular injections, respectively. After intravenous treatment, the total body clearance (Cl) and volume of distribution at steady state (VSS) were determined as 73.79±5.83 ml/h/kg and 318.65±30.06 ml/kg, respectively. After intramuscular injection, the peak concentration (Cmax; 22.55±0.89 ìg/ml) was observed at 1.67±0.26 h and the absorption half-life (t1/2ka) and absolute bioavailability (F) were calculated as 0.40±0.13 h and 93.03%±7.07%, respectively. The current results demonstrated the rapid and complete absorption, however, poor distribution and rapid elimination of ceftiofur and its active metabolites in black-bone silky fowl.

Purification and characterization of lysozyme from Chinese Lueyang black-bone Silky fowl egg white

Lysozyme, an important antibacterial protein, is an enzyme that cleaves the glycosidic bond between N-acetylmuramic acid and N-acetylglucosamine of peptidoglycan in cell walls. The novel lysozyme was purified and characterized from Chinese Lueyang black-bone silky fowl (CBSF) egg white, and its N-terminal amino acid sequence, enzymatic properties, and antibacterial activity were investigated. The CBSF lysozyme was purified using adsorption chromatography, ammonium sulfate precipitation, ion exchange chromatography, and size-exclusion chromatography. The purification fold and yield were 3.28 and 14.69%, respectively. The purified lysozyme was revealed as a single protein band with SDS–PAGE and had a MALDI-TOF/TOF molecular weight of 14305.57 Da and a final specific activity of 3.49 × 105 U/mg protein using Micrococcus lysodeikticus as a substrate. The optimum temperature and pH of the lysozyme were 50 °C and 6.0, respectively. The 20 N-terminal amino acid residues of the purified lysozyme were determined to be KVFGRCELAAAMKRHGLDNY, showing some homology to the N-terminus of the odontophoridae egg white lysozyme. The purified lysozyme exerted a potent antimicrobial activity toward indicator microorganisms, including Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 25923, and Escherichia coli ATCC 25922. However, its inhibition of gram-negative activity was weaker than that of the Gram-positive bacteria.

Effects of two cooking methods on the taste components of Sanhuang chicken and Black-bone silky fowl meat

In this work, the effects of two cooking methods (stewing and roasting) on the taste components of Sanhuang chickens (SHC) and Black-bone silky fowl (BSF) meat were investigated. The contents of taste-active compounds, including free amino acids, organic acid, and 5′-nucleotides, were determined by high-performance liquid chromatography. The results showed that the aspartic acid and glutamic acid contents of roasted SHC thigh were higher than other seven samples. Lactic acid was the main organic acid in the samples, accounting for 65%–80% of the total organic acid content. The content of organic acids and 5′-nucleotides was higher in stewing sample than roasting. The content of organic acids was higher in the chicken breast sample than thigh. However, the content of 5′-nucleotides was higher in the chicken thigh sample than the breast. The equivalent umami concentration of roasted SHC thigh (0.35 g MSG/100 g) was the highest. Practical applications Cooking methods exert vital effects on the taste of chicken, but less information could be obtained from the reference about the effects of cooking methods on the taste components of chicken. The aims of this work were to investigate the influences of two cooking methods (stewing and roasting) on taste components of SHC and BSF. This work could provide more scientific recommendation for the development of chicken seasonings and more suitable cooking methods.

Characterization of Melanin Isolated and purified by Multi-Stage Enzymatic Reaction from Korean Whole Black Fowl (Gallus gallus domesticus)

Background/Objectives: Yoensan Ogae, Korean whole black fowl, has been used as a superb traditional medicine. It is known that the natural melanin promotes the health by means of such as photoprotection, antioxidation, free radical-scavenging, and anti-inflammatory effects. Methods: The meats of black body fowl aged one-year were obtained from the Ginsan farm located at Yonsan, Korea. To prepare the meat slurry, the meats were dissected, separated, minced, and homogenized. To isolate and purify the melanin, the meat slurry was transferred into a reactor vessel, and 1% (w/v) of papain, flavozyme, and bromelaine were added into the solution. The chemical and morphological properties were analyzed by a FTIR, elemental analyzer, amino acids analyzer, and scanning electron microscope. Findings: The content of protein included in extracted melanin from Yoensan Ogae was 12.6% and its major amino acids were glutamic, aspartic, leucine, alanine, and lysine. The ratio of S to N of the melanin presumed that most melanin was eumelanin and its structure was similar to the sepia melanin. The purified melanin was similar to that of human hair, sepia, and black bone silky fowl reported from previous studies. Improvements/Applications: Yoensan Ogae containing a plenty of melanin would be expected to supply the health benefits and applied to be ingredients as functional foods and cosmetic industry.

Preparation, Identification and Antioxidant Properties of Black-Bone Silky Fowl (Gallus gallus domesticus Brisson) Iron(II)-Oligopeptide Chelate.

Black-bone silky fowl iron(II)-oligopeptide chelate was synthesized from iron(II) solution and the black-bone silky fowl oligopeptide, which was extracted from the muscle protein of black-bone silky fowl (Gallus gallus domesticus Brisson). Orthogonal array analysis was used to determine the optimal conditions for the iron(II)-oligopeptide chelate preparation. Ultraviolet-visible (UV-Vis) spectroscopy, electron microscopy, and Fourier transform infrared (FTIR) spectroscopy were used to identify the structure of iron(II)-oligopeptide chelate. 2-Diphenyl-1-picrylhydrazyl (DPPH) and superoxide radical scavenging assays were performed to compare the antioxidant abilities of the black-bone silky fowl oligopeptide and iron(II)-oligopeptide chelate. The optimal conditions for iron(II)-oligopeptide chelate preparation were 4% of the black-bone silky fowl oligopeptide and a ratio of the black- -bone silky fowl oligopeptide to FeCl2·4H2O of 5:1 at pH=4. Under these conditions, the chelation rate was (84.9±0.2) % (p<0.05), and the chelation yield was (40.3±0.1) % (p<0.05). The structures detected with UV-Vis spectroscopy, electron microscopy and FTIR spectra changed significantly after chelation, suggesting that Fe(II) ions formed coordinate bonds with carboxylate (-RCOOŻ) and amino (-NH2) groups in the oligopeptides, confirming that this is a new oligopeptide-iron chelate. The iron(II)-oligopeptide chelate had stronger scavenging activity towards DPPH and superoxide radicals than did the black-bone silky fowl oligopeptide.

Microstructure Features of Proventriculus and Ultrastructure of the Gastric Gland Cells in Chinese Taihe Black-bone Silky Fowl (Gallus gallus domesticus Brisson).

To investigate microstructure of proventriculus and ultrastructure of the gastric gland cells from Chinese Taihe black-bone silky fowl (BSF), the proventriculus of 4-week-old BSF was sampled. Conventional histological and transmission electron microscope (TEM) methods were used in this study. The wall of the Taihe BSF proventriculus was consisted of four layers, the mucous, submucosa, muscularis externa and the serosa as others birds. The muscularis externa of the birds' proventriculus contained three layers. Much of the melanin was present in loose connective tissue of lamina propria, submucosa, and muscularis externa unlike others. In addition, the ultrastructure of the gastric gland cells was observed by TEM. There was only one kind of gland cell, for example oxynticopeptic cell in proventriculus of Taihe BSF. The oxynticopeptic cells contained numerous mitochondria, cisternae of rough endoplasmic reticulum (CRER), intracellular canaliculi (IC) that secrete hydrochloric acid and small amounts of pepsinogen granules. The rough endoplasmic reticulum (RER) was irregular cisternae with ribosomes and surrounded tightly the mitochondria along their configuration. The electron-dense pepsinogen granules were round with various sizes. The neighbouring oxynticopeptic cells were closed up with tight junction and gap junction. The inter-space between the neighbouring oxynticopeptic cells was stenosis or was filled with electron-dense extracellular substance. In conclusion, the gastric gland cells of Chinese Taihe BSF proventriculus were only oxynticopeptic cells that secrete hydrochloric acid and pepsinogen, but no parietal cells and chief cells of mammal. The gastric gland cells of proventriculus were underdeveloped compared with those of mammals.

Genetic mutations of avian leukosis virus subgroup J strains extended their host range

The genetic diversity of avian leukosis virus subgroup J (ALV-J) is determined not only by the env gene, but also by its 3' UTR and 3' LTR. They all play important roles in extending the host range and tumour development. In the present study, one ALV-J strain (ZB110604-6) from Black-Bone Silky Fowl (BSF) and three ALV-J strains (ZB110604-3/4/5) from grey partridge (GP), which bore multiple tumours and breed in one house of Farm A, were demonstrated extending their host to GP, while two other ALV-J strains (LC110515-3/4) from BSF of Farm B could not infect the embryo fibroblast of GP. The BSF is a unique species of chicken in China, while the GP is a close relative of the pheasant that previously demonstrated resistance to ALV-J. Histopathology showed that various tumours were induced by ALV-J in the two species. Phylogenetic tree analysis showed that the isolates from Farms A and B, rather than species, belong to two different clusters of ALV-J. Genetic mutations analysis revealed that the isolates obtained from Farm A showed a higher frequency of mutation in the hypervariable region 2 domain than in other variable regions of the gp85 gene. From the nucleotide alignment of the 3' UTR and 3' LTR gene, and the spectrum of tumours observed in this study, we speculate that the deletions or mutations in the redundant transmembrane region, E element and U3 (CAAT boxes, CArG box and Y box) might associate with tumour formation and development. The extension of the host range of ALV-J to the GP suggested that housing different species together provides more opportunities for ALV-J to evolve rapidly.

Identification of two novel multiple recombinant avian leukosis viruses in two different lines of layer chicken

Avian leukosis virus (ALV) is the most common oncogenetic retrovirus that emerges spontaneously as a result of recombination between exogenous viruses, exogenous viruses and endogenous viruses, and exogenous viruses and non-homologous cellular genes. In the present study, two natural recombinant avian leukosis viruses (rALVs) (LC110515-5 and LC110803-5) carrying a subgroup C gp85 gene, a subgroup E gp37 gene, and a subgroup J 3'UTR and 3'LTR were isolated from two different lines of layer flocks, Black-bone silky fowl (BSF) and commercial layer chicken, that suffered from myeloid leukosis. Although tumours were not observed in rALV-infected individual chickens, other non-neoplastic inflammatory lesions were evident. The two rALVs were cultured on DF-1 cells and identified by PCR, immunofluorescence assay and gene sequencing. The gp85 nucleotide sequence in the two isolates displayed a high identity (>95 %) with that of the gp85 gene in ALV-C, but the identity was less than 90 % with ALV-A/B/D/E and only 51 % with ALV-J. Phylogenetic analysis of the nucleotide and amino acid sequences confirmed that the two isolates were recombinant between ALV-C, ALV-E and ALV-J. Subgroup C ALV is rarely found in field cases. This report is the first to provide evidence that ALV-C has recombined with ALV-E and ALV-J in two different chicken lines. The source and characteristics of the two rALVs and ALV-C need to be further investigated.

Isolation and identification of antioxidative peptides from pilot‐scale black‐bone silky fowl (Gallus gallus domesticus Brisson) muscle oligopeptides

A pilot-scale production was developed to produce oligopeptide powder from black-bone silky fowl (Gallus gallus domesticus Brisson) muscle (BSFP) by two-step enzymatic hydrolysis and multistage separation. The resultant BSFP was assessed for antioxidant activities against four free radicals (hydroxyl, 1,1-dipheny-2-picrylhydrazyl (DPPH), superoxide and peroxyl) and against the peroxidation of linoleic acid in a lipid peroxidation model system. After separation by reversed-phase high-performance liquid chromatography (RP-HPLC), five major fractions of BSFP were tested for DPPH radical scavenging activity and subjected to mass spectrometry to identify the active peptides. BSFP showed potential antioxidant activity in four assay systems. Three RP-HPLC fractions produced higher antioxidant effect than BSFP, with Fraction 4 showing the strongest activity. A total of 18 peptides were identified, and two peptides - Leu-Trp-Arg and Asn-Met - had strong scavenging activity, with IC50 values of 2.28 ± 0.05 and 4.65 ± 0.09 mg mL(-1) , respectively. Asn-Met is a novel antioxidative peptide that has not been previously reported. The results showed that the pilot-scale production of BSFP was a practical way to produce peptides with high value and potential antioxidant activity. BSFP and its antioxidative peptides can be a source of natural antioxidant and used as a food additive.

Purification and identification of novel antioxidative peptide released from Black-bone silky fowl (Gallus gallus domesticus Brisson)

Papain-treated Black-bone silky fowl (BSF) muscle hydrolysate was subjected to 6 kDa cutoff membrane ultrafiltration, and the resulting BSF peptides (<6 kDa) were purified by two-step reverse-phase high-performance liquid chromatography. The molecular weight (MW) distribution and amino acid composition were investigated for characterization of the BSF peptides. The results showed that the major amino acids of BSF peptides were Glu, Tyr, Lys, Asp, Leu, Ala, Thr and Pro, and the MW was from 281 to 7,982 Da. BSF peptides exhibited a strong antioxidant capacity. At 10 mg/mL, they displayed more powerful \( {\text{O}}_{2}^{ \cdot - } \), DPPH· and ABTS·+ scavenging activity and reducing power than carnosine. The peptide fraction 8 with more hydrophilicity revealed stronger \( {\text{O}}_{2}^{ \cdot - } \) and ABTS·+ scavenging activity and reducing power than BSF peptides and carnosine. Besides, a peptide, separated from fraction 8 and showed the strongest antioxidant capacity, was purified and identified by LC-ESI-MS/MS to be Glu-Pro-Asp-Arg-Tyr (678 Da).

Study of the Physico-chemical Properties and Antioxidant Activity of Extracted Melanins

Ultraviolet (UV) light tends to cause skin damage; melanin can scavenge reactive oxygen species (ROS) produced from UV to protect skin from damage caused by free radicals. The purpose of this study was to investigate the physico-chemical properties and antioxidant activity of extracted melanins. Melanins were extracted from black tea (BT-melanin), black soybean (BS-melanin) and black-bone silky fowl (SF-melanin); they were then compared with synthetic melanin (SY-melanin). Three kinds of extracted melanins have absorbance ability in broad-spectrum (190-450 nm) wavelength. The experiment’s results indicated that the solubility in 25? water, organic solvents, 1 M NH4OH, and 1 M HCl of the three extracted melanins was similar to the solubility of synthetic melanin. The melanins also showed good stability in various light sources. The extracted melanins could chelate with Fe2+ and Cu2+. An in vitro study showed that the extracted melanin enhanced the survivability of fibroblast cells with 25 ?g mL-1 concentration after UV irradiation (254 nm, 0.09 mW cm2 -1) (p<0.05). All of the extracted melanins increased glutathione peroxidase (GSH-Px) and catalase activity when exposed to UV light (p<0.001). They inhibited the peroxidation of lipid (TBARS) and scavenged superoxide anion (p<0.001) induced by UV irradiation. According to the above results, the melanins extracted from black tea, black soybean, and black-bone silky fowl are similar in their physico-chemical properties, and they have the capacity for anti-oxidation and photoprotection from UV irradiation.