Gushi Chickens Research Articles

Integrated GWAS and transcriptome analysis reveals key genes associated with muscle fibre and fat traits in Gushi chicken

ABSTRACT 1. In the following experiment meat quality traits of a Gushi-Anka F2 resource population were measured, and their heritability estimated. Intramuscular fat (IMF) had medium heritability (0.35) but leg muscle fibre density (LMD), leg muscle fibre diameter (LMF), breast muscle fibre density (BMD), fresh fat content (FFA), and absolute dry fat content (AFC) had low heritability (0–0.2). The IMF presented the most important genetic additive effect among the poultry meat quality-related traits studied. 2. The phenotypic data of meat quality traits in the Gushi-Anka F2 resource population were combined with genotyping by sequencing (GBS) data to obtain genotype data. Six meat quality traits in 734 birds were analysed by GWAS. Based on these variants, 83 significant (–log10(p) > 4.42) single nucleotide polymorphisms and four quantitative trait loci (QTL) regions corresponding to 175 genes were identified. Further linkage disequilibrium (LD) analysis was conducted on chromosome 13 (Chr13) and chromosome 27 (Chr27) QTL regions. 3. Based on the transcriptome data and GWAS results, 12 shared genes - ITGB3, DNAJC27, ETV4, C7orf50, FKBP1B, G3BP1, IGF2BP1, KCNH6, LOC416263, SCARA5, SMIM5 and TBL1XR1 were identified as candidate genes influencing muscle fibre and fat traits.

Application effectiveness of "Youxin-1" in genetic diversity and structure analysis of local chickens.

China's local chicken breeds are rich in resources, and have formed different germplasm characteristics in the process of long-term selection and evolution. Scientific assessment of population genetic diversity and identification of inter-breed genetic structure are of great value to the protection and innovative utilization of local chicken breed resource. In order to evaluate the application effectiveness of 23K SNP chip "Youxin-1" in the analysis of genetic diversity and genetic structure of local chickens, we used RADseq to identify genomic genetic variation of 21 local chicken breeds and developed 23K chip "Youxin-1". The genetic statistics of each variety were calculated based on two sets of SNP data, and correlation, fitting and phylogenetic analysis were carried out to evaluate the application effectiveness of the chip. The results showed that the observed heterozygosity (Ho), polymorphism information content (PIC), inbred coefficient (FROH) and genetic differentiation coefficient (Fst) calculated based on the two SNP data sets were basically consistent in the 21 local chicken breeds. The genetic diversity of Langya chicken (LA), Piao chicken (PJ) and Wenchang chicken (WC) was relatively rich. The genetic diversity of Bian chickens (BJ), Langshan chickens (LS), Gushi chickens (GS), Dongxiang blue-eggshell chickens (DX) and Beijing fatty chickens (BY) was relatively poor, and the correlation coefficients of Ho, PIC, FROH and average Fst in the two groups were 0.794, 0.901, 0.926 and 0.984, respectively, all reaching extremely significant levels (P<0.01) with a high degree of fit (P<0.001) and R2 were 0.644, 0.827, 0.916 and 0.927. For the two sets of SNP data, the evolutionary tree constructed by neighbor-joining (NJ) method and maximum likelihood (ML) method was reasonable, and the 21 local chicken breeds were generally divided into six categories, which was consistent with the formation history and geographical distribution of the varieties. The 23K chip also realized reasonable clustering of the five new varieties without individual deviation. There are some differences in the estimation of genetic statistics using SNP with different densities, and data standardization is needed. 23K chip has good efficacy in the analysis of genetic diversity and structure of local chickens.

In vitro antibacterial activity of danofloxacin against Escherichia coli in Gushi chickens and its residue depletion following multiple oral administration

This study aimed to investigate the in vitro antibacterial activity of danofloxacin against Escherichia coli isolated from Gushi chickens, as well as the tissue distribution and residue depletion of danofloxacin in Gushi chickens following multiple oral administration. A total of 42 clinical E. coli strains were isolated from the cloaca of locally farmed Gushi chickens between August and October 2023. Then the minimum inhibitory concentration (MIC) of danofloxacin against these isolates was determined by broth microdilution method. Additionally, 42 healthy Gushi chickens were randomly divided into 6 groups, and danofloxacin was orally administered at a dose of 5 mg/kg body weight (BW) for 3 consecutive days. Plasma, intestinal content, and tissue samples, including muscle, skin + fat, liver, kidney, lung, and intestine, were collected at 4, 12, 24, 48, 72, and 120 h after the last administration. Danofloxacin concentrations in all samples were determined using a high-performance liquid chromatography (HPLC) method. The average concentration vs. time data were then subjected to noncompartmental analysis using Phoenix software, and withdrawal periods for danofloxacin in Gushi chickens were further determined with WT1.4 software, setting a 95% confidence interval. Results indicated a notable inhibitory effect of danofloxacin on E. coli, with an MIC50 of 0.5 μg/mL. Additionally, danofloxacin exhibited widespread distribution in Gushi chickens, detectable in all collected samples. Among all tissues, the liver exhibited the highest concentration, followed by the intestine. Even on the fifth day postadministration, danofloxacin persisted in skin + fat, liver, and lung. The elimination half-lives (t1/2λzs) of danofloxacin varied across samples: skin + fat (47.87 h), lung (30.61 h), liver (22.07 h), plasma (16.05 h), muscle (12.53 h), intestine (9.83 h), and kidney (6.34 h). Considering residue depletion and the maximum residue limit (MRL) of danofloxacin in poultry set by Chinese regulatory authorities, withdrawal periods for the kidney, muscle, liver, and skin + fat were determined as 1.03, 1.38, 3.34, and 5.85 d, respectively, rounded to a final withdrawal time of 6 d.

Depletion of tilmicosin residue in Gushi chickens following oral administration via drinking water.

This study aimed to examine the depletion of tilmicosin residues in Gushi chickens following the administration at a concentration of 75 mg/L in their drinking water for three consecutive days. Plasma, liver, kidney, lung, muscle, and skin + fat samples were collected from 6 chickens at 6 h, 1, 3, 5, and 7 days after the treatment. Tilmicosin concentrations in the samples were determined using a high-performance liquid chromatography (HPLC) method. The findings revealed that the highest tilmicosin residues were detected in the liver, followed by the kidney, lung, skin + fat, muscle, and plasma. Notably, at 7 days post-treatment, no drug residue was detected in all samples except for the liver and kidney. The non-compartmental model was employed to calculate relevant pharmacokinetic parameters. The elimination half-lives (t1/2λz ) of tilmicosin were as follows, ranked from long to short: skin + fat (45.42 h), liver (44.17 h), kidney (40.06 h), plasma (37.64 h), lung (31.39 h), and muscle (30.05 h). Considering the current residue depletion and the maximum residue limits (MRLs) set by Chinese regulatory authorities, the withdrawal times for tilmicosin were estimated as 18.91, 10.81, and 8.58 days in the kidney, liver, and skin + fat, respectively. A rounded-up value of 19 days was selected as the conclusive withdrawal time. Furthermore, based on the observed tilmicosin concentrations in plasma and lung, combined with previously reported minimum inhibitory concentration (MIC) values against Mycoplasma gallisepticum, the current dosing regimen was deemed adequate for treating Mycoplasma gallisepticum infections in Gushi chickens.

Assessing the conservation impact of Chinese indigenous chicken populations between ex-situ and in-situ using genome-wide SNPs

Conservation programs require rigorous evaluation to ensure the preservation of genetic diversity and viability of conservation populations. In this study, we conducted a comparative analysis of two indigenous Chinese chicken breeds, Gushi and Xichuan black-bone, using whole-genome SNPs to understand their genetic diversity, track changes over time and population structure. The breeds were divided into five conservation populations (GS1, 2010, ex-situ; GS2, 2019, ex-situ; GS3, 2019, in-situ; XB1, 2010, in-situ; and XB2, 2019, in-situ) based on conservation methods and generations. The genetic diversity indices of three conservation populations of Gushi chicken showed consistent trends, with the GS3 population under in-situ strategy having the highest diversity and GS2 under ex-situ strategy having the lowest. The degree of inbreeding of GS2 was higher than that of GS1 and GS3. Conserved populations of Xichuan black-bone chicken showed no obvious changes in genetic diversity between XB1 and XB2. In terms of population structure, the GS3 population were stratified relative to GS1 and GS2. According to the conservation priority, GS3 had the highest contribution to the total gene and allelic diversity in GS breed, whereas the contribution of XB1 and XB2 were similar. We also observed that the genetic diversity of GS2 was lower than GS3, which were from the same generation but under different conservation programs (in-situ and ex-situ). While XB1 and XB2 had similar levels of genetic diversity. Overall, our findings suggested that the conservation programs performed in ex-situ could slow down the occurrence of inbreeding events, but could not entirely prevent the loss of genetic diversity when the conserved population size was small, while in-situ conservation populations with large population size could maintain a relative high level of genetic diversity.

Weighted gene co-expression network analysis identified hub genes critical to fatty acid composition in Gushi chicken breast muscle

BackgroundThe composition and content of fatty acids in the breast muscle are important factors influencing meat quality. In this study, we investigated the fatty acid composition and content in the breast muscle of Gushi chickens at different developmental stages (14 weeks, 22 weeks, and 30 weeks). Additionally, we utilized transcriptomic data from the same tissue and employed WGCNA and module identification methods to identify key genes associated with the fatty acid composition in Gushi chicken breast muscle and elucidate their regulatory networks.ResultsAmong them, six modules (blue, brown, green, light yellow, purple, and red modules) showed significant correlations with fatty acid content and metabolic characteristics. Enrichment analysis revealed that these modules were involved in multiple signaling pathways related to fatty acid metabolism, including fatty acid metabolism, PPAR signaling pathway, and fatty acid biosynthesis. Through analysis of key genes, we identified 136 genes significantly associated with fatty acid phenotypic traits. Protein–protein interaction network analysis revealed that nine of these genes were closely related to fatty acid metabolism. Additionally, through correlation analysis of transcriptome data, we identified 51 key ceRNA regulatory networks, including six central genes, 7 miRNAs, and 28 lncRNAs.ConclusionThis study successfully identified key genes closely associated with the fatty acid composition in Gushi chicken breast muscle, as well as their post-transcriptional regulatory networks. These findings provide new insights into the molecular regulatory mechanisms underlying the flavor characteristics of chicken meat and the composition of fatty acids in the breast muscle.

Genetic architecture and key regulatory genes of fatty acid composition in Gushi chicken breast muscle determined by GWAS and WGCNA

BackgroundFatty acids composition in poultry muscle is directly related to its tenderness, flavour, and juiciness, whereas its genetic mechanisms have not been elucidated. In this study, the genetic structure and key regulatory genes of the breast muscle fatty acid composition of local Chinese chicken, Gushi-Anka F2 resource population by integrating genome-wide association study (GWAS) and weighted gene co-expression network analysis (WGCNA) strategies. GWAS was performed based on 323,306 single nucleotide polymorphisms (SNPs) obtained by genotyping by sequencing (GBS) method and 721 chickens from the Gushi-Anka F2 resource population with highly variable fatty acid composition traits in the breast muscle. And then, according to the transcriptome data of the candidate genes that were obtained and phenotypic data of fatty acid composition traits in breast muscle of Gushi chickens at 14, 22, and 30 weeks of age, we conducted a WGCNA.ResultsA total of 128 suggestive significantly associated SNPs for 11 fatty acid composition traits were identified and mapped on chromosomes (Chr) 2, 3, 4, 5, 13, 17, 21, and 27. Of these, the two most significant SNPs were Chr13:5,100,140 (P = 4.56423e-10) and Chr13:5,100,173 (P = 4.56423e-10), which explained 5.6% of the phenotypic variation in polyunsaturated fatty acids (PUFA). In addition, six fatty acid composition traits, including C20:1, C22:6, saturated fatty acid (SFA), unsaturated fatty acids (UFA), PUFA, and average chain length (ACL), were located in the same QTL intervals on Chr13. We obtained 505 genes by scanning the linkage disequilibrium (LD) regions of all significant SNPs and performed a WGCNA based on the transcriptome data of the above 505 genes. Combining two strategies, 9 hub genes (ENO1, ADH1, ASAH1, ADH1C, PIK3CD, WISP1, AKT1, PANK3, and C1QTNF2) were finally identified, which could be the potential candidate genes regulating fatty acid composition traits in chicken breast muscle.ConclusionThe results of this study deepen our understanding of the genetic mechanisms underlying the regulation of fatty acid composition traits, which is helpful in the design of breeding strategies for the subsequent improvement of fatty acid composition in poultry muscle.

Pharmacokinetics of Danofloxacin in Gushi Chickens after Single Oral and Intravenous Administration.

This study aimed to determine the pharmacokinetics of danofloxacin in Gushi chickens after a single oral (PO) and intravenous (IV) dose at 5 mg/kg body weight (BW). Thirty-two Gushi chickens, aged 20 weeks, were selected and divided into two groups at random, with each group consisting of 16 chickens, evenly distributed between males and females. Following danofloxacin administration, blood samples were taken at predetermined time intervals and the plasma was separated. The concentrations of danofloxacin in plasma were quantified by HPLC with a fluorescence detector. Then the concentrations versus time data were subjected to non-compartmental analysis (NCA) using Phoenix software (version: 8.1.0). After administering danofloxacin orally at a dose of 5 mg/kg BW to Gushi chickens, our results demonstrated that the peak concentration reached 0.53 μg/mL at 4 h. The half-life of absorption (t1/2ka) was determined to be 2.37 ± 1.60 h, and the bioavailability (F) was calculated as 40.12 ± 15.83%. For both oral and intravenous administration, the area under the concentration-time curve (AUC0-∞) was determined to be 4.72 ± 1.86 and 11.76 ± 3.25 h·µg/mL, respectively. The corresponding elimination half-life (t1/2λz) was measured as 11.24 ± 3.90 and 10.17 ± 3.72 h. Moreover, the mean residence time (MRT) was calculated as 10.20 ± 2.47 and 7.05 ± 1.97 h for these respective routes. Based on the calculated AUC/MIC ratio values, it can be inferred that the 5 mg/kg BW dosage of danofloxacin, whether administered orally or intravenously, is expected to effectively treat Escherichia coli and Pasteurella multocida infections in Gushi chickens.

Transcriptome analysis reveals FABP5 as a key player in the development of chicken abdominal fat, regulated by miR-122-5p targeting

BackgroundThe development of abdominal fat and meat quality are closely related and can impact economic efficiency. In this study, we conducted transcriptome sequencing of the abdominal fat tissue of Gushi chickens at 6, 14, 22, and 30 weeks, and selected key miRNA-mRNA regulatory networks related to abdominal fat development through correlation analysis.ResultsA total of 1893 differentially expressed genes were identified. Time series analysis indicated that at around 6 weeks, the development of chicken abdominal fat was extensively regulated by the TGF-β signaling pathway, Wnt signaling pathway, and PPAR signaling pathway. However, at 30 weeks of age, the apoptosis signaling pathway was the most significant, and correlation analysis revealed several genes highly correlated with abdominal fat development, including Fatty Acid Binding Protein 5 (FABP5). Based on miRNA transcriptome data, it was discovered that miR-122-5p is a potential target miRNA for FABP5. Cell experiments showed that miR-122-5p can directly target FABP5 to promote the differentiation of preadipocytes.ConclusionThe present study confirms that the key gene FABP5 and its target gene miR-122-5p are critical regulatory factors in the development of chicken abdominal fat. These results provide new insights into the molecular regulatory mechanisms associated with the development of abdomen-al fat in chickens.

Mining of kokumi peptides in chicken broth with peptidomics

Chicken soup is a high-quality traditional seasoning. In this study, 16,306 polypeptides in the Gushi chicken soup were analyzed by ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS), and two polypeptides with kokumi flavor (TPDFVR and TPELLH) were obtained by comparing the amino acid structure and performing electronic tongue analysis. The taste thresholds of TPDFVR and TPELLH are 0.4 and 0.2 mmol/L, respectively. Therefore, the taste time of the chicken soup can be prolonged in the mouth, and the taste of the chicken soup can be improved. Also, the electronic tongue experiment proved that the two polypeptides have a strong sour and salty taste. The experimental results revealed that the peptidomics method is quick and effective in discovering peptides associated with taste.

Genome-Wide Genetic Structure of Henan Indigenous Chicken Breeds.

There are five indigenous chicken breeds in Henan Province, China. These breeds have their own unique phenotypic characteristics in terms of morphology, behavior, skin and feather color, and productive performance, but their genetic basis is not well understood. Therefore, we analyzed the genetic structure, genomic diversity, and migration history of Henan indigenous chicken populations and the selection signals and genes responsible for Henan gamecock unique phenotypes using whole genome resequencing. The results indicate that Henan native chickens clustered most closely with the chicken populations in neighboring provinces. Compared to other breeds, Henan gamecock's inbreeding and selection intensity were more stringent. TreeMix analysis revealed the gene flow from southern chicken breeds into the Zhengyang sanhuang chicken and from the Xichuan black-bone chicken into the Gushi chicken. Selective sweep analysis identified several genes and biological processes/pathways that were related to body size, head control, muscle development, reproduction, and aggression control. Additionally, we confirmed the association between genotypes of SNPs in the strong selective gene LCORL and body size and muscle development in the Gushi-Anka F2 resource population. These findings made it easier to understand the traits of the germplasm and the potential for using the Henan indigenous chicken.

Identification and genetic analysis of major gene ST3GAL4 related to serum alkaline phosphatase in chicken

Alkaline phosphatase (ALP) is a marker of osteoblast maturation and an important indicator of bone metabolism. The activity of ALP can reflect the bone metabolism and growth traits of animals, so the polymorphism affecting ALP expression deserves further study. In this study, we identified an SNP site in ST3GAL4 found by genome-wide association studies (GWAS) in previous studies, 8 SNPs were also identified by DNA sequencing. Interestingly, there were 4 SNPs (rs475471G > A, rs475533C > T, rs475621A > G, rs475647C > A) completely linked by haplotype analysis. Therefore, we selected a tag SNP rs475471G > A to further analyze the ALP level of different genotypes in Hubbard leg disease population and an F2 chicken resource population produced by Anka and Gushi chickens and carried out population genetic analysis in 18 chicken breeds. Association analysis showed that this QTL within ST3GAL4 was highly correlated with ALP level. The mutant individuals with genotype AA had the highest ALP level, followed by GA and GG carriers. The mutant individual carriers of AA and GA genotype had higher values for body weight (BW), chest width (CW), body slanting length (BSL), pelvis width (PW) at 4-week, the semi-evisceration weight (SEW), evisceration weight (EW) and Leg weight (LW) than GG genotypes. The amplification and typing of 4852 DNA samples from 18 different breeds showed GG genotype mainly existed in egg-type chickens and dual-type chickens, while the AA genotype was mainly distributed in commercial broilers and F2 resource population. The individual carriers of the AA genotype had the highest ALP and showed better growth performance. Besides, tissue expression analysis used Cobb broiler showed significant differences between different genotypes in the spleen and duodenum. Taken together, this was the first time to determine 9 SNPs within ST3GAL4 related to ALP in chickens, 4 of them were complete linkage with each other, which provides useful information on the mutation of ST3GAL4 and could predict the serum ALP level of chicken early and as an effective potential molecular breeding marker for chickens.

Analysis of Gut Microbial Communities and Resistance Genes in Pigs and Chickens in Central China.

Basic data concerning the gut microbiota of the main animal husbandry breeds (pigs and chickens) are scarce in China. The dynamics of gut microbiota (pigs and chickens) in China and antibiotic resistance genes carried by microorganisms in the natural environment are unknown. Free range and factory-farmed Gushi chickens and Huainan pigs were divided into eight groups. Faecal samples were collected from each group, and the metagenomic sequencing method was used to detect each group of samples. The resistance genes showed the following trend, from high to low relative abundance: tetW was the highest, followed by tetW/N/W, then lnuA; and others from high to low were mdtB, lnuC, ANT6-la, ErmB, mdtC, ErmQ, tetBP, vatE, evgS, acrB, cpxA, mefA, Escherichia coli-ampC, tetL, yojl, AcrF and mdtA. All groups administered enrofloxacin and oregano oil did not develop a drug-resistant phenotype during the 5-day treatment period, as grouped in this trial. In 2022, after Announcement No. 194 of the Ministry of Agriculture and Rural Affairs in China, the antimicrobial resistance (AMR) trend declined, but it did not fundamentally change, presumably due to the impact of environmental pollution caused by the long-term use of antimicrobials.

CircRNAs Related to Breast Muscle Development and Their Interaction Regulatory Network in Gushi Chicken.

Circular RNAs (circRNAs) play a significant regulatory role during skeletal muscle development. To identify circRNAs during postnatal skeletal muscle development in chickens, we constructed 12 cDNA libraries from breast muscle tissues of Chinese Gushi chickens at 6, 14, 22, and 30 weeks and performed RNA sequencing. In total, 2112 circRNAs were identified, and among them 79.92% were derived from exons. CircRNAs are distributed on all chromosomes of chickens, especially chromosomes 1-9 and Z. Bioinformatics analysis showed that each circRNA had an average of 38 miRNA binding sites, 61.32% of which have internal ribosomal entry site (IRES) elements. Furthermore, in total 543 differentially expressed circRNAs (DE-circRNAs) were identified. Functional enrichment analysis revealed that DE-circRNAs source genes are engaged in biological processes and muscle development-related pathways; for example, cell differentiation, sarcomere, and myofibril formation, mTOR signaling pathway, and TGF-β signaling pathway, etc. We also established a competitive endogenous RNA (ceRNA) regulatory network associated with skeletal muscle development. The results in this report indicate that circRNAs can mediate the development of chicken skeletal muscle by means of a complex ceRNA network among circRNAs, miRNAs, genes, and pathways. The findings of this study might help increase the number of known circRNAs in skeletal muscle tissue and offer a worthwhile resource to further investigate the function of circRNAs in chicken skeletal muscle development.

Transcriptome analysis of the testes of male chickens with high and low sperm motility

The reproductive performance of chicken breeders has significant economic importance in the poultry industry, and sperm motility is an indicator of reproductive performance. This study performed RNA-seq of the testes of Gushi chicken roosters with high and low sperm motility and identified differentially expressed RNAs involved in sperm motility. RNA-seq analysis showed that 73 and 67 differentially expressed mRNAs were up- and downregulated, and 47 and 56 differentially expressed long non-coding RNAs were up- and downregulated, respectively. The genes related to sperm motility and spermatogenesis included KIFC1, KCNK2, and REC8. Functional enrichment analysis revealed that the pathways related to sperm motility included oxidative phosphorylation and glycine, serine, and threonine metabolism. In addition, the MSTRG.15920.1-REC8-MSTRG.11860.2-VWC2 pathway may regulate sperm motility. This study helped elucidate the molecular genetic mechanism of sperm motility in chicken.

MiR-181a-5p can inhibit the proliferation and promote the differentiation of chicken primary myoblasts

ABSTRACT 1. Myoblast proliferation and differentiation is one of the most important biological processes in the development of skeletal muscle. MicroRNAs (miRNAs) play a crucial role in this process. 2. In this study, the expression level of miR-181a-5p was detected, which found that miR-181a-5p was expressed differently in different tissues, different embryonic ages, and different differentiation stages of primary myoblasts in Gushi chickens. 3. The effect of miR-181a-5p was further investigated on chicken primary myoblasts (CPMs). The results of cell counting kit-8 (CCK-8), 5-ethynyl-2’-deoxyuridine (EdU) and cell cycle showed that miR-181a-5p could inhibit the proliferation of CPM. The miR-181a-5p promoted the expression of MYOD, MYOG, and MYHC. MYHC protein immunofluorescence experiments showed that miR-181a-5p increased the area of myotubes. 4. In total, 63 potential target genes of miR-181a-5p in mRNA transcriptome data analysis were identified. Functional enrichment analysis was performed on these target genes, and ASNS, SMYD1, and FOS were found to play regulatory roles in biological processes such as muscle development. It was speculated that miR-181a-5p played a role in myoblast development through these genes. 5. In conclusion, miR-181a-5p can inhibit the proliferation of chicken myoblasts and promote the differentiation of chicken myoblasts. This study laid the foundation for further research on the regulatory mechanism of miR-181a-5p in the development of skeletal muscle and the formation of excellent meat quality traits in Gushi chicken.

Immunomodulatory effects of chicken soups prepared with the native cage-free chickens and the commercial caged broilers

The objective of this study was to compare the immunomodulatory effects of the chicken soups prepared with the native free-range chickens and the commercial caged broilers in the immunosuppressive mice. The immunosuppressive mice model was established by the intraperitoneal injection of 100 mg of cyclophosphamide (CTX) per kg body weight. The powders of Gushi Chicken Soup (GCS), Honglashan Chicken Soup (HCS), and Cobb Broiler Soup (CBS) were prepared by high-pressure stewing followed by spray drying. The chicken soups' nutrient content and the effects of three chicken soups on the body weight, organ index, blood index, and serum cytokine and immunoglobulin contents in the immunosuppressive mice were determined. The three chicken soups promoted the recovery of immunosuppressive mice, but the expression mechanisms were different. The GCS was more effective than the HCS and CBS in restoring blood index, promoting cytokine secretion, and increasing immunoglobulin content (P < 0.05). The HCS stimulated the Th1-type immune response and promoted immunoglobulin secretion (P < 0.05), while the CBS increased the production of CD4+ and promoted the T-cell functions better than other soups (P < 0.05). Although soups from the native free-range chickens and the commercial caged broilers showed distinctly different mechanisms in promoting immunity, both could be used as potential immunomodulators.

Integrative analysis of hypothalamic transcriptome and genetic association study reveals key genes involved in the regulation of egg production in indigenous chickens

Indigenous chicken products are increasingly favored by consumers due to their unique meat and egg quality. However, the relatively poor egg-laying performance largely impacts the economic benefits and hinders sustainable development of the local chicken industry. Thus, excavating key genes and effective molecular markers associated with egg-laying performance is necessary to improve egg production via genetic selection in indigenous breeds. In the present study, comparative hypothalamic transcriptome between pre-laying (15 weeks old) and peak-laying (30 weeks old) Lushi blue-shelled-egg (LBS) chicken was performed. A total of 518 differentially expressed genes (DEGs) were identified. Among the DEGs, 64 genes were enriched in 10 Gene Ontology (GO) terms associated with reproductive regulation via GO analysis and considered as potential candidate genes regulating egg-laying performance. Of the 64 genes, 16 showed high connectivity (degree≥12) by protein–protein interaction (PPI) network analysis and were considered as potential core candidate genes (PCCGs). To further look for key candidate genes from the PCCGs, firstly, the expression patterns of the 16 genes were examined in the hypothalamus of two indigenous breeds (LBS and Gushi (GS) chickens) between the pre-laying and peak-laying stages using quantitative real-time PCR (qRT-PCR). Eleven out of the 16 genes showed significantly differential expression (P<0.05) with the same changing trends in the two breeds. Then, correlations between the expression levels of the above 11 genes and egg numbers and reproductive hormone concentrations in serum were investigated in high-yielding and low-yielding GS chickens. Of the 11 genes, eight showed significant correlations (P<0.05) between their expression levels and egg numbers, and between expression levels and reproductive hormone concentration in serum. Furthermore, an association study on single nucleotide polymorphisms (SNPs) identified in these eight genes and egg production traits was carried out in 640 GS hens, and a significant association (P<0.05) between the SNPs and egg numbers was confirmed. In conclusion, the eight genes, including CNR1, AP2M1, NRXN1, ANXA5, PENK, SLC1A2, SNAP25 and TRH, were demonstrated as key genes regulating egg production in indigenous chickens, and the SNPs sites within the genes might be served as markers to provide a guide for indigenous chicken breeding. These findings provide a novel insight for further understanding the regulatory mechanisms of egg-laying performance and developing molecular markers to improve egg production of indigenous breeds.

Weighted gene co-expression network indicates that the DYNLL2 is an important regulator of chicken breast muscle development and is regulated by miR-148a-3p

BackgroundThe characteristics of muscle fibers determine the growth and meat quality of poultry. In this study, we performed a weighted gene co-expression network analysis (WGCNA) on the muscle fiber characteristics and transcriptome profile of the breast muscle tissue of Gushi chicken at 6, 14, 22, and 30 weeks.ResultsA total of 27 coexpressed biological functional modules were identified, of which the midnight blue module had the strongest correlation with muscle fiber and diameter. In addition, 7 hub genes were found from the midnight blue module, including LC8 dynein light chain 2 (DYNLL2). Combined with miRNA transcriptome data, miR-148a-3p was found to be a potential target miRNA of DYNLL2. Experiments on chicken primary myoblasts (CPMs) demonstrated that miR-148a-3p promotes the expression of myosin heavy chain (MYHC) protein by targeting DYNLL2, proving that it can promote differentiation of myoblasts.ConclusionsThis study proved that the hub gene DYNLL2 and its target miR-148-3p are important regulators in chicken myogenesis. These results provide novel insights for understanding the molecular regulation mechanisms related to the development of chicken breast muscle.

MiR-30a-3p can inhibit the proliferation and promote the differentiation of chicken primary myoblasts

ABSTRACT 1. Chicken muscle is an important factor in meat quality and its development is controlled by a complex regulatory network. 2. The following study examined the expression of miR-30a-3p in Gushi chicken breast muscle tissue and found that it was differentially expressed at different embryonic stages, reaching a peak in the 14-day-old embryo (E14). 3. The effect of miR-30a-3p on chicken primary myoblasts (CPMs) was explored. Results from both cell counting kit-8 (CCK-8) and 5-ethynyl-2’-deoxyuridine (EdU) showed that this can inhibit the proliferation of myoblasts, and through cell cycle experiments, the inhibition of myoblast proliferation was found, which may be due to G0/G1 arrest in the cell cycle. 4. The effect of miR-30a-3p on the differentiation of myoblasts was studied. The results showed that miR-30a-3p can promote the expression of MYOD, myogenin (MYOG), and myosin heavy chain (MYHC) genes to promote the differentiation of myoblasts. Through MYHC protein immunofluorescence experiments, it was found that miR-30a-3p can effectively increase the area of myotubes. 5. Finally, mRNA transcriptome data was analysed, which showed that miR-30a-3p has 51 potential target genes. Among them, forkhead box O3 (FOXO3), ankyrin repeat domain 1 (ANKRD1), and insulin-induced 1 (INSIG1) genes were differentially expressed at different developmental stages and were enriched in Gene Ontology (GO) terms, such as cell differentiation and cellular developmental process. The data showed that tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein gamma (YWHAG), BUB1 mitotic checkpoint serine/threonine kinase (BUB1), and growth arrest and DNA damage-inducible 45 (GADD45) genes were enriched in the cell cycle pathway. 6. It can be speculated that miR-30a-3p plays roles through these genes in myoblast development. This research provides information for further improving knowledge of the chicken muscle development regulation network.