Black-bone Chicken Research Articles

Transcript expression profiling of fibromelanosis-related genes in black-bone chickens

ABSTRACT 1. The aim of the present study was to identify differentially expressed genes (DEGs) and metabolic pathways involved in this phenotype. Fibromelanosis is the most striking feature of black-bone chickens, such as the Silkie and Dongxiang indigenous breeds. Due to the accumulation of eumelanin in connective tissues, fibromelanosis manifests as black colouration of the skin, muscles, gut, and periosteum. Studies on fibromelanosis can provide useful information pertaining to human diseases and offer commercial value to the poultry industry. However, the genetic basis of fibromelanosis remains unclear. 2. Digital gene expression analysis was performed on black and white skin samples collected from the HW1 black-bone chicken line to detect differences in genome-wide expression patterns. A total of >30 billion bp were sequenced, and 2,707,926,466 bp and 2,948,782,964 bp of clean data obtained for creation of libraries for black and white skin, respectively. In total, 252 DEGs from 15,508 mapped genes were identified with 83 up-regulated in white skin and 169 up-regulated in black skin. 3. Gene ontology analysis highlighted that genes from the extracellular region and associated components were abundant among the DEGs. Pathway analysis revealed that many DEGs were linked to amino acid metabolism and the immune system. qRT-PCR validation using 14 genes showed good conformity with the sequence analysis of fibromelanosis-related genes. 4. The results showed that L-dopachrometautomerase precursor (DCT), tyrosine aminotransferase (TAT), 4-hydroxyphenylpyruvate dioxygenase (HPD) from the tyrosine metabolism pathway, coagulation factor II (F2), fibrinogen beta chain (FGB), plasminogen (PLG) and complement component 7 (C7) from the complement and coagulation cascades were important genes in the fibromelanosis process in black-bone chickens. These candidate genes require further correlation analysis and functional verification.

Comparative transcriptomic analysis of ovaries from high and low egg-laying Lingyun black-bone chickens.

Egg‐laying rate is mainly determined by ovarian function and regulated by the hypothalamic‐pituitary‐gonadal axis; however, the mechanism by which the ovary regulates the egg‐laying rate is still poorly understood. The purpose of this study was to compare the differences in the transcriptomes of the ovary of Lingyun black‐bone chickens with relatively high and low egg‐laying rates and screen candidate genes related to the egg‐laying rate. RNA‐sequencing (RNA‐Seq) was conducted to explore the chicken transcriptome from the ovarian tissue of six Lingyun black‐bone chickens with high (group G, n = 3) and low (group D, n = 3) egg‐laying rates. The results showed that 235 differentially expressed genes (DEGs) were identified between the chickens with high and low egg‐laying rates; among them, 209 DEGs were up‐regulated and 26 DEGs were down‐regulated. Gene Ontology analysis showed that the up‐regulated 209 DEGs were enriched in 50 GO terms and the down‐regulated 26 DEGs were enriched in 40 GO terms. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that up‐regulated DEGs were significantly enriched in 25 pathways and down‐regulated DEGs were significantly enriched in three pathways. Among the pathways, we found the longevity regulating pathway‐multiple species pathway, Estrogen signalling pathway and PPAR signalling pathway may have an essential function in regulating the egg‐laying rate. The results highlighted DEGs in the ovarian tissues of relatively high and low laying Lingyun black‐bone chicken and identified essential candidate genes related to the egg‐laying rate, thereby providing a theoretical basis for improving the egg‐laying rate of Lingyun black‐bone chicken.

Carnosine Content and Its Association with Carnosine-Related Gene Expression in Breast Meat of Thai Native and Black-Bone Chicken.

Simple SummaryFunctional meat has become an important issue in the poultry industry because chicken meat is a rich source of carnosine. Additionally, carnosine synthesis is regulated by an ATP-grasp domain-containing protein 1 (CARNS1). However, no studies have elucidated the role of carnosine content and CARNS1 in Thai native and black-bone chicken. Thus, the aim of this study was to select and develop mating programs for functional meat in Thai chicken populations. Our results indicated that different breeds and ages of chickens have different amounts of carnosine and levels of CARNS1 expression. The carnosine content and CARNS1 expression decreased linearly as chicken age increased. Moreover, a moderate correlation was observed between carnosine content and CARNS1 expression levels. Therefore, the CARNS1 gene could be used to study marker assistant selection in the future.This study aimed to investigate the carnosine content and ATP-grasp domain-containing protein 1 (CARNS1) gene expression and their relationship with breast meat of Black Chinese (BC), KU-Phuparn (KP), Pradu Hang Dam (PD), and Black Chinese × Pradu Hang Dam (Sri Mok: SM) to aid in the selection and mating programs for developing functional meat in Thai chicken populations. The results show that the carnosine content in each breed and breed group varied from 428.08 to 553.93 mg/100 g, whereas the relative expression of CARNS1 ranged from 0.84 to 1.56. The BC and KP chicken breeds had a higher carnosine content (p < 0.01) and higher CARNS1 expression level (p < 0.05) than the SM and PD chicken breeds. The carnosine content and relative gene expression for each age ranged from 423.02 to 577.83 mg/100 g and 0.68 to 1.83, respectively. At 4 weeks of age, the carnosine content (p < 0.01) and gene expression (p < 0.05) were the highest. However, they decreased as chicken age increased further. The carnosine content and gene expression linearly decreased as chicken age increased (p < 0.01). The correlation coefficient between the level of gene expression and carnosine content was moderately positive. The results from this study showed that different breeds and ages of chickens have different amounts of carnosine, and CARNS1 could act as a biomarker to study marker-assisted selection to improve functional meat in the chicken population in Thailand.

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.

Taste-Active and Nutritional Components of Thai Native Chicken Meat: A Perspective of Consumer Satisfaction.

The taste-active and nutritional components of Thai native, broilers, black-boned, and spent hen chickens were analyzed. The amounts of tasty amino acids especially glutamic acid were the highest in Thai native chicken. The black-boned chicken had the highest arginine content, related to the least amount of consumer satisfaction. Concerning nutritional quality, choline, and taurine were deemed important for brain function. The black-boned chicken showed the highest choline and taurine contents, unlike that of the spent hens. In contrast, broilers presented the highest betaine content, which might be attributed to their lipid metabolism. L-carnitine content was abundant in black-boned and Thai native chickens. Moreover, the amounts of essential amino acids were high in Thai native chicken. In conclusion, black-boned chicken proved to be an excellent nutritional source for health-conscience consumers, whereas the Thai native chickens were flavourful and delicious.

Lactobacillus reuteri-derived extracellular vesicles maintain intestinal immune homeostasis against lipopolysaccharide-induced inflammatory responses\xa0in\xa0broilers

BackgroundLactobacillus reuteri strains are widely used as probiotics to prevent and treat inflammatory bowel disease by modulating the host’s immune system. However, the underlying mechanisms by which they communicate with the host have not been clearly understood. Bacterial extracellular vesicles (EVs) have been considered as important mediators of host-pathogen interactions, but their potential role in commensals-host crosstalk has not been widely studied. Here, we investigated the regulatory actions of EVs produced by L. reuteri BBC3, a gut-associated commensal bacterium of Black-Bone chicken, in the development of lipopolysaccharide (LPS)-induced intestinal inflammation in a chicken model using both in vivo and in vitro experiments.ResultsL. reuteri BBC3 produced nano-scale membrane vesicles with the size range of 60–250 nm. Biochemical and proteomic analyses showed that L. reuteri BBC3-derived EVs (LrEVs) carried DNA, RNA and several bioactive proteins previously described as mediators of other probiotics’ beneficial effects such as glucosyltransferase, serine protease and elongation factor Tu. In vivo broiler experiments showed that administration of LrEVs exerted similar effects as L. reuteri BBC3 in attenuating LPS-induced inflammation by improving growth performance, reducing mortality and decreasing intestinal injury. LrEVs suppressed the LPS-induced expression of pro-inflammatory genes (TNF-α, IL-1β, IL-6, IL-17 and IL-8), and improved the expression of anti-inflammatory genes (IL-10 and TGF-β) in the jejunum. LrEVs could be internalized by chicken macrophages. In vitro pretreatment with LrEVs reduced the gene expression of TNF-α, IL-1β and IL-6 by suppressing the NF-κB activity, and enhanced the gene expression of IL-10 and TGF-β in LPS-activated chicken macrophages. Additionally, LrEVs could inhibit Th1- and Th17-mediated inflammatory responses and enhance the immunoregulatory cells-mediated immunosuppression in splenic lymphocytes of LPS-challenged chickens through the activation of macrophages. Finally, we revealed that the reduced content of both vesicular proteins and nucleic acids attenuated the suppression of LrEVs on LPS-induced inflammatory responses in ex vivo experiments, suggesting that they are essential for the LrEVs-mediated immunoregulation.ConclusionsWe revealed that LrEVs participated in maintaining intestinal immune homeostasis against LPS-induced inflammatory responses in a chicken model. Our findings provide mechanistic insight into how commensal and probiotic Lactobacillus species modulate the host’s immune system in pathogens-induced inflammation.

Chronological Expression of PITX2 and SIX1 Genes and the Association between Their Polymorphisms and Chicken Meat Quality Traits.

Simple SummaryThe production of chickens plays an increasingly important role in people’s daily life because of the high nutritional quality and relatively low cost. Meanwhile, with the improvement of living standards, the requirements for meat quality have also increased significantly. Thus, the improvement of meat quality is becoming more and more important in chicken breeding. Studies have shown that meat quality is closely related to the development of skeletal muscle, which is a complex process regulated by many genes. Paired-like homeodomain transcription factor 2 (PITX2) and SIX homeobox 1 (SIX1) genes are involved in skeletal muscle development, and their polymorphisms were significantly associated with the carcass and body size traits of chickens in our previous studies. The objective of the present study was to detect the chronological expression of them on the pectoral muscles, and evaluate whether their single nucleotide polymorphisms (SNPs) are associated with the meat quality traits in chickens. Our results could provide useful information for the functional research of regulatory mechanisms of meat quality and marker assisted-selection for chicken production and quality.Meat quality is closely related to the development of skeletal muscle, in which PITX2 and SIX1 genes play important regulatory roles. The present study firstly provided the data of chronological expression files of PITX2 and SIX1 genes in the post-hatching pectoral muscle and analyzed the association of their polymorphisms with the meat quality traits of Wuliang Mountain Black-bone (WLMB) chickens. The results showed that both PITX2 and SIX1 genes were weakly expressed in the second and third weeks, and then increased significantly from the third week to the fourth week. Furthermore, there was a significant positive correlation between the expression levels of the two genes. Twelve and one SNPs were detected in the chicken PITX2 and SIX1 genes, respectively, of which four SNPs (g.9830C > T, g.10073C > T, g.13335G > A, g.13726A > G) of the PITX2 gene and one SNP (g.564G > A) of the SIX1 gene were significantly associated with chicken meat quality traits. For the PITX2 gene, chickens with the CT genotype of g.9830C > T showed the highest meat color L*, shear force (SF), pH, and the lowest electrical conductivity (EC), and drip loss (DL) (p < 0.05 or p < 0.01); chickens with the CC genotype of g.10073C > T had the lowest L*, pH, and the highest DL (p < 0.01). For the SIX1 gene, chickens with the GG genotype of g.564G > A had the highest (p < 0.05) SF and pH. Furthermore, pH had a significant correlation with all the other meat quality traits. The current study could contribute to the research of regulatory mechanisms of meat quality and lay the foundation for improving meat quality based on marker-assisted selection in chickens.

Genetics and breeding of a black-bone and blue eggshell chicken line. 1. Body weight, skin color, and their combined selection

An experimental population of chickens was developed from the cross between 2 indigenous Chinese breeds, Dongxiang blue eggshell and Jiangshan black-bone. This breeding was aimed at eventually combining dark heavy black-bone body and blue eggshell, into a single dual-purpose breed. BW was recorded and skin L∗, a∗, and b∗ color parameters were measured by a Chroma Meter at several ages (56, 105, 150, 200, 250, and 300 d). At 250 d, 3 independent observers classified skin darkness using a 3-level visual scale (1 = light, 2 = intermediate, 3 = dark). The 7-level average visual skin darkness, calculated for each chicken, was highly correlated (−0.658 and −0.612 in females and males, respectively) with skin L∗ (lightness), indicating that the accurately measured L∗ is reliable and useful reverse expression of visual skin darkness of black-bone chickens. Mean BW and skin L∗ of both sexes increased with age, to 2,063 and 1,522 g in males and females, respectively, at 300 d, and to 63 and 55 L∗ units in males and females, respectively, at 250 d. The population's full-pedigree allowed estimating heritability and genetic correlations between traits. The heritability estimates of BW were similar in both sexes, increasing from around 0.25 at 56 d, to 0.53 to 0.60 at 150 d, and 0.57 to 0.62 at 300 d. Over the 5 ages, heritability estimates of skin L∗ were moderate to high, ranging from 0.45 to 0.58 in females, and from 0.31 to 0.65 in males, and the genetic correlations between BW and L∗ ranged mostly from 0.20 to 0.45. These low-to-moderate correlations between high BW and high L∗ (low darkness) are unfavorable; hence they were combined into an index, standardized BW minus standardized L∗, allowing future selection for high BW with low L∗. With high heritability of this index, 0.487 (females at 300 d) and 0.410 to 0.555 (males at 150 d or older), simultaneous improvements in BW and skin darkness appear to be feasible. The methodology used in this study can be useful in chicken populations experimentally bred for combination of high BW and other body characteristics.

Effects of Macleaya cordata extract on laying performance, egg quality, and serum indices in Xuefeng black-bone chicken

The abuse of antibiotic growth promoters (AGPs) in feed has led to drug resistance and ecological damage would threaten human health eventually. Natural plants have become a hotspot in the research and application of substituting AGPs because of their advantages of safety, efficiency, and availability. This study was conducted to investigate the effects of Macleaya cordata extract (MCE) in the diet of Xuefeng black-bone chicken on laying performance, egg quality, and serum indices. In this study, 576 birds (47-week-old) were evenly distributed between 4 treatments with 6 replicates of 24 hens each. The control group was fed a basal diet without MCE and the remaining groups received 100, 150, or 200 mg/kg MCE for 84 d. Results revealed that the strength and thickness of the eggshell increased significantly with the dietary addition of MCE (P < 0.05). The serum concentrations of glutathione peroxidase increased in the MCE groups (P < 0.01). Simultaneously, progesterone, follicle stimulating hormone, estradiol as well as serum luteinizing hormone levels also increased with the addition of MCE (P < 0.05). Compared with the control group, supplementation of MCE significantly decreased the tumor necrosis factor-α and interleukin-6 levels (P < 0.01). In summary, it was concluded that diet addition of 200 mg/kg MCE ameliorated egg quality, enhanced anti-oxidation and immune activity, and regulated hormone secretion of Xuefeng black-bone chicken.

First Report on Better Functional Property of Black Chicken Meat from India

Background: Indian domesticated chickens have a wide variety of phenotypes. Unlike other chicken breeds, Kadaknath chicken has black meat and is used by indigenous tribal people for its invigorating and therapeutic properties. To look for the functional traits that might be contributing towards the acclaimed benefits, free radical scavenging capacity and metal chelating ability of Kadaknath meat were explored for the first time in comparison to the commercial Cobb broiler. Methods: During the period 2018-2020, breast and thigh meat were collected from chickens (n=20/ group) at their commercial slaughter age. Meat extract was used for qualitative evaluation of protein as well as the antioxidant capacity utilizing diverse in vitro methods corresponding to different antioxidation mechanisms.Result: Protein concentration (g/100g of tissue) in Kadaknath breast (25.25 ± 0.31) and thigh (19.98 ± 0.29) meat was significantly (P less than 0.05) higher than the Cobb. Breast meat had better scavenging capacity than the thigh. The superiority of the antioxidant capacity of Kadaknath meat was explicitly established by more than one in vitro assay. Free radical scavenging assays viz. 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) (ABTS); 1,1-diphenyl-2-picrylhydrazyl (DPPH) and Cupric reducing antioxidant capacity (CUPRAC) had significantly (P less than 0.05) higher values for Kadaknath in comparison to the Cobb broiler meat. Ferric reducing antioxidant power (FRAP) values (mM Fe2+/g of tissue) were also more in breast meat of Kadaknath (26.97±0.37) than the Cobb (15.24±0.40). Similarly, FRAP values were higher in Kadaknath (33.85±0.47) than the Cobb (19.2±0.31) thigh meat. Kadaknath had higher antioxidant capacity as reflected by metal chelation inhibition value. These findings help to explain the unique nutritional and functional characteristics of Kadaknath black-bone chicken and provide basic research data for exploring the commercial potential of its meat in the fields of functional foods, cosmeceuticals and nuutraceuticals.

Consistency of dark skeletal muscles in Thai native black-bone chickens (Gallus gallus domesticus)

Black-bone chickens (Gallus gallus domesticus) have become economically valuable, particularly in Southeast Asia as a consequence of popular traditional Chinese medical practices. Chickens with whole body organ darkness are considered to have higher value and are, therefore, more often requested. This research study aimed to investigate the darkness in 34 skeletal muscles of 10 Thai black-bone chickens (five males and five females). The evaluation of muscle darkness was done on two levels: (i) a color chart was employed at the macroanatomical level and (ii) by using melanin pigment to evaluate the structure at the microanatomy level. The results revealed that the accumulation of melanin pigment in the muscle tissue was observed in the endomysium, perimysium and epimysium. With respect to the results of the color chart test, iliotibialis lateralis pars preacetabularis, gastrocnemius, fibularis longus and puboischiofemoralis pars medialis showed the highest degree of darkness, while serratus profundus, pectoralis, iliotibialis cranialis, flexor cruris lateralis, and flexor cruris medialis appeared to be the least dark. In addition, we found that the highest and lowest amounts of melanin pigment was noted in the flexor carpi ulnaris and pectoralis (p < 0.05), respectively; however, there was no significant difference (p > 0.05) observed between the sexes. These results reveal that the 34 specified muscles of black-bone chickens showed uneven distribution of darkness due to the differing accumulations of melanin pigments of each muscle.This information may provide background knowledge for a better understanding of melanin accumulation and lead to breeding improvements in Thai black-bone chickens.

Using non-linear models to describe growth curves for Thai black-bone chickens

Using non-linear models to describe growth curves for Thai black-bone chickens

Effects of different levels of Hermetia illucens larvae meal on performance, egg quality, yolk fatty acid composition and oxidative status of laying hens

To investigate the supplemental effects of Hermetia illucens larvae meal (HILM) on the production, egg quality, yolk fatty acid composition, egg amino acid content, oxidative status, and immune indexes of laying hens. A total of 432 Xuefeng black-bone chickens (45-week-old) were randomly assigned to 4 treatments with 6 replicates per treatment and 18 hens in each replicate. The laying hens were fed the basal diet supplemented with 0%, 1%, 3%, and 5% HILM (CON, HILM-1, HILM-3, and HILM-5, respectively) for 56 d. The experimental diets were isonitrogenous and isoenergetic. The highest egg weight and Haugh unit were obtained with 3% HILM supplementation, but the HILM-3 or HILM-5 supplementation have negative effect on the eggshell thickness, yolk index, and albumen height during the early stage of the experiment. The HILM supplementation linearly or quadratically (p < .05) increased the C14:0, C17:0, C18:2n6c, C20:2 contents of yolk, the Glu, Val, Met, Phe, and Leu contents of egg, the T-SOD and CAT activities, and the NDV-Ab and AIV-Ab levels of plasma. With increasing supplementation of HILM in the basal diet, FCR, the C16:0 and C16:1 contents of yolk, MDA content and IL-2 level of plasma decreased both linearly or quadratically (p < .05). In conclusion, Hermetia illucens larvae meal can be a suitable alternative protein source for Xuefeng black-bone chicken. Dietary supplementation of 3% HILM in basal diets may be a feasible means of effectively increasing the production performance of laying hens, and partially enhanced hens’ antioxidant capability and immune function. HIGHLIGHTS Supplementation of 1% HILM had no effect on laying hens, and supplementation of 3% HILM increased the egg weight and Haugh unit. Supplementation of 3% HILM or 5% HILM have a negative effect on the eggshell thickness, yolk index, and albumen height during the early stage of the experiment. Supplementation of 3% HILM increased the C14:0, C17:0, and C20:2 contents of yolk, the Glu, Val, Met, Phe, and Leu contents of egg. The plasma antioxidant status and immune response improved by dietary addition of HILM at 3% levels.

Palygorskite combined probiotics improve the laying performance, hatching performance, egg quality, plasma antioxidative status, and immune response of broiler breeders

This experiment was conducted to investigate the effects of different supplementation levels of palygorskite and probiotics complex (Pal-Pro) on laying performance, hatching performance, egg quality, plasma antioxidative status, and immune response of broiler breeders. A total of 432 Xuefeng black-bone chickens (42-week-old) were randomly assigned into four treatments with six replicates of 18 hens. The broiler breeders were fed the basal diet supplemented with 0, 250, 500, and 750 mg/kg Pal-Pro for 8 weeks. The Pal-Pro supplementation linearly or quadratically increased (p < .05) laying rate, fertilisation rate, hatchability of fertile eggs, heath hatched chicks rate, eggshell thickness, yolk index, total antioxidant capacity, activities of total superoxide dismutase, catalase, glutathione peroxidase, and contents of immunoglobulins, interleukin-2, and tumour necrosis factor-α in plasma. With Pal-Pro supplementation increased, feed convention ratio during 5–8 and 1–8 week, embryo mortality, malondialdehyde linearly decreased (p < .05). This finding suggested that dietary supplementation with 750 mg/kg Pal-Pro administration could improve the antioxidative status and immunoglobulins contents in plasma of broiler breeders, which may contribute to an increase in broiler’s laying rate, hatching performance, egg quality, such as eggshell thickness and yolk index. HIGHLIGHTS Dietary supplementation of Pal-Pro decreased the feed conversion ratio and embryo mortality of broiler breeders. Dietary supplementation of Pal-Pro improved the laying rate, fertility, hatchability of fertile eggs, and yolk index of broiler breeders. Dietary supplementation of Pal-Pro enhanced the antioxidant capacity and the level of immunoglobulins in the plasma.

Identification of Igf2bp1 gene family and effect on chicken myoblast proliferation

ABSTRACT The function of Igf2bp1 regulated muscle development in Lueyang black-bone chickens is to be investigated. The insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) belongs to the family of single-stranded RNA-binding proteins (IGF2BP1-3). IGF2BP1 is abundantly expressed in a broad range of foetal tissues, but only in a limited number of normal adult tissues, and is involved in biological regulation processes, including cell proliferation, differentiation, metabolism and migration, especially in tumour cells. Recent study has reported Igf2bp1 was a key gene that regulated the body size of Pekin ducks. We found that the expression level of Igf2bp1 gradually decreased with age in the leg muscle of Lueyang black-bone chicken, but its function in chicken muscle development is unknown. Firstly, the evolutionary relationship of Igf2bp1 gene family was analysed in chicken. Additionally, Igf2bp1-overexpressed myoblasts of Lueyang black-bone chicken were constructed. The results showed that Igf2bp1 plays a negative role in cell proliferation by the CCK8 and 5-ethynyl-2′-deoxyuridine assay. Moreover, Igf2bp1 inhibited myogenesis by detecting the myoblast proliferation markers of pax7, the expression of myogenic differentiation markers, MyoD, MyoG and Myf5 in myoblasts. Thus, Igf2bp1 can inhibit chicken myoblast proliferation and differentiation by regulating key gene expression of myogenesis, which is not conducive to the growth and development of skeletal muscle in Lueyang black chickens.

Effects of fermented feeds and ginseng polysaccharides on the intestinal morphology and microbiota composition of Xuefeng black-bone chicken.

Fermented feeds contain abundant organic acids, amino acids, and small peptides, which improve the nutritional status as well as the morphology and microbiota composition of the intestine. Ginseng polysaccharides exhibit several biological activities and contribute to improving intestinal development. Here, Xuefeng black-bone chickens were fed a basal diet fermented by Bacillus subtilis, Saccharomyces cerevisiae, Lactobacillus plantarum, and Enterococcus faecium, with or without ginseng polysaccharides. The 100% microbially fermented feed (Fe) and 100% microbially fermented feed and ginseng polysaccharide (FP) groups showed significantly increased villus height and villus height to crypt depth ratio, and decreased crypt depth in the jejunum. In the 100% complete feed and ginseng polysaccharide (Po) group, the villus height to crypt depth ratio was significantly increased, crypt depth was reduced, and villus height remained unaffected. Next, we studied the intestinal microbial composition of 32 Xuefeng black-bone chickens. A total of 10 phyla and 442 genera were identified, among which Firmicutes, Proteobacteria, and Bacteroidetes were the most dominant phyla. At the genus level, Sutterella and Asteroleplasma abundance increased and decreased, respectively, in the FP and Po groups. Sutterella abundance was positively correlated to villus height and villus height to crypt depth ratio, and negatively correlated to crypt depth, and Asteroleplasma abundance was positively correlated to crypt depth and negatively correlated to villus height to crypt depth ratio. At the species level, the FP group showed significantly increased Bacteroides_vulgatus and Eubacterium_tortuosum and decreased Mycoplasma_gallinarum and Asteroleplasma_anaerobium abundance, and the Po group showed significantly increased Mycoplasma_gallinarum and Asteroleplasma_anaerobium abundance. Moreover, bacterial abundance was closely related to the jejunum histomorphology. Asteroleplasma_anaerobium abundance was positively correlated with crypt depth and negatively correlated with villus height to crypt depth ratio. Mycoplasma_gallinarum abundance was positively correlated to villus height, and Bacteroides_vulgatus and Eubacterium_tortuosum abundance was positively correlated with villus height to crypt depth ratio and negatively correlated with crypt depth. Therefore, fermented feeds with ginseng polysaccharides may be used as effective alternatives to antibiotics for improving intestinal morphology and microbial composition.

Investigation of the CEBPA gene expression pattern and association analysis of its polymorphisms with meat quality traits in chickens

Meat quality is closely related to the fat deposition which is regulated by a cascade of transcription factors. As a transcription factor, the CCAAT/enhancer binding protein alpha (CEBPA) is considered as one of the key molecules regulating adipogenesis. Therefore, the objective of this study was to detect the expression pattern of the CEBPA gene and evaluate whether its single nucleotide polymorphisms (SNPs) were associated with the meat quality traits in Wuliang Mountain Black-bone (WLMB) chickens. The results showed that the chicken CEBPA mRNA was widely expressed in the 11 tissues, and the expression pattern of it might be tissue- and time-specific different. The locus of g.74C > G was not significantly associated with chicken meat quality. For the locus of g.552G > A, chickens with the GG genotype showed higher pH (p < 0.01), lower drip loss (p < 0.01) and higher intramuscular fat (p < 0.05) than those with other genotypes. It suggested that polymorphisms of the CEBPA gene were significantly associated with the meat quality traits of WLMB chickens. The results of this study contribute to the functional research of the CEBPA gene and lay the foundation for improving meat quality based on the marker-assisted selection in chickens.

Breeding history and candidate genes responsible for black skin of Xichuan black-bone chicken

BackgroundDomesticated chickens have a wide variety of phenotypes, in contrast with their wild progenitors. Unlike other chicken breeds, Xichuan black-bone chickens have blue-shelled eggs, and black meat, beaks, skin, bones, and legs. The breeding history and the economically important traits of this breed have not yet been explored at the genomic level. We therefore used whole genome resequencing to analyze the breeding history of the Xichuan black-bone chickens and to identify genes responsible for its unique phenotype.ResultsPrincipal component and population structure analysis showed that Xichuan black-bone chicken is in a distinct clade apart from eight other breeds. Linkage disequilibrium analysis showed that the selection intensity of Xichuan black-bone chickens is higher than for other chicken breeds. The estimated time of divergence between the Xichuan black-bone chickens and other breeds is 2.89 ka years ago. Fst analysis identified a selective sweep that contains genes related to melanogenesis. This region is probably associated with the black skin of the Xichuan black-bone chickens and may be the product of long-term artificial selection. A combined analysis of genomic and transcriptomic data suggests that the candidate gene related to the black-bone trait, EDN3, might interact with the upstream ncRNA LOC101747896 to generate black skin color during melanogenesis.ConclusionsThese findings help explain the unique genetic and phenotypic characteristics of Xichuan black-bone chickens, and provide basic research data for studying melanin deposition in animals.

Identification of differentially expressed genes associated with egg production in black-boned chicken

ABSTRACT 1. Muchuan black-bone chicken is well known in China for its meat quality and medicinal properties; however, its egg-laying performance is not ideal. To better understand the molecular mechanisms of black-boned chicken egg-laying, high-throughput RNA sequencing was performed to compare differences in the pituitary transcriptome between three high-rate (group H) and three low-rate (group L) egg production chickens. 2. In total, 171 differentially expressed genes (DEGs) were identified between the two groups, of which 113 were upregulated and 58 were downregulated in group L. Some of these genes are known to be related to hormone secretion or the regulation of reproductive processes; these include prolactin-releasing hormone (PRLH), distal-less homeobox 6 (DLX6), interferon regulatory factor 4 (IRF4), and cilia and flagella associated protein 69 (CFAP69). Notably, expression pattern analysis indicated that both PRLH and DLX6 may influence egg-laying performance. 3. The dataset provided a foundation for discovering important genes and pathways involved in the chicken egg-laying process, and may help to improve understanding of the molecular mechanisms of chicken reproduction.

Identifying and profiling the microRNAs associated with skin colour in the Muchuan black-bone chicken

MicroRNAs (miRNAs) are an abundant class of small non-protein-coding RNAs that regulate gene expression in plants and animals. Skin colour is an important economic consideration in chicken production, and chickens with black skin have high market value. Nevertheless, little research has been conducted on miRNA regulation of melanogenesis in chicken skin. In this study, we sampled the dorsal skins of chickens with black (BS) and white (WS) skin to construct six small RNA libraries. High-throughput sequencing technology was then used to identify which miRNAs were expressed differentially between the BS and WS phenotypes. A total of 645 known and 64 novel miRNAs were identified from the six sequencing libraries. Additionally, the expression of 18 miRNAs was significantly different between the two phenotypes, including 9 miRNAs that were up-regulated, and 9 that were down-regulated. We identified 2 miRNAs, i.e. miR-204 and miR-6631-5p, that may be important for melanogenesis in chicken skin. Our data contribute to the understanding of the molecular mechanism, through miRNA regulation, of melanin formation in chicken skin. Highlights Differentially expressed miRNAs were identified in black skin (BS) and white skin (WS) of black-bone chickens Eighteen DEMs were detected in BS and WS groups. miR-204 and miR-6631-5p were potential candidates influencing skin melanogenesis in chicken.