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Infant hepatitis B vaccine coverage in China is high, with over 95% of infants immunized; however, high vaccine coverage can often mask low timeliness. The vaccination interval between the second and third doses is not clearly defined by immunization guidelines in China. This retrospective cohort study assessed the time interval distribution of hepatitis B vaccination among a cohort of randomly selected live births from the Centers for Disease Control and Prevention across four provinces or municipalities in China between January 2017 and December 2021. Among the infants analyzed, 163,224 received the first dose of hepatitis B vaccine with 146,905 (90.0%) and 135,757 (83.2%) infants receiving the second and third doses, respectively. A total of 132,577 (90.2%) infants received the second dose between 28 and 61 days after the first dose. Of the 119,437 (88.0%) infants that completed the hepatitis B series between 61 and 214 days after the second dose 87,067 (64.1%) infants were vaccinated with the third dose between 151 and 180 days after the second dose. The time interval distribution varied across the four provinces or municipalities (p

Background: HPV vaccination is the key measure to prevent cervical cancer, but uptake in China lags behind global targets. Understanding Chinese guardians’ preferences is key to improving vaccine acceptance and coverage. Methods: A nationwide online discrete choice experiment survey was conducted among 4933 Chinese guardians across seven provinces in 2022 to quantify preferences and willingness to pay. Attributes included effectiveness, safety, duration, valency, location, and out-of-pocket cost. Results: Out of the 4933 guardians who participated in the study, 4179 (84.72%) were mothers. More than 60% of the guardians belonged to the age group of 35–44 years. Additionally, over half of the respondents (53.15%) had daughters between the ages of 9 and 14 years. Respondents were open to accepting the HPV vaccine with 95% efficacy and exceptional safety. Guardians expressed a preference for longer protection duration (specifically 15 years (βa = 0.340, 95% CI: 0.31, 0.37)) and higher vaccine valency. As for willingness to pay, the respondents placed the highest value on vaccine efficacy, being willing to shell out more than USD 1100 for 95% protection as compared to 50%. Furthermore, very good safety commanded a premium of over USD 800 when compared to average safety. When it comes to willingness to uptake, a vaccine with 95% efficacy led to a more than 35% increase in acceptance as compared to one with 50% efficacy. Similarly, exceptional safety resulted in an increased willingness to uptake of over 25% when compared to average safety. Conclusions: The DCE highlighted effectiveness, safety, and durability as critical drivers of HPV vaccine acceptance, but substantial barriers persist regarding adolescent female coverage in China.

Abstract Background Parents are usually the decision-makers for vaccinations of children. Therefore, it is important to understand parental beliefs and attitudes toward severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine for themselves and their children when it was approved for children age 3–17. Method A cross-sectional survey based on an anonymous online questionnaire for parents was conducted in seven provinces of China, and demographic information, vaccination history, parental decision motives, and health belief model toward themselves and their children were collected, respectively. Results The overall parental hesitancy rate toward themselves was 20.30%, and that toward their children was 7.80%. More parental concerns on disease severity (odd ratio [OR] = 1.11, 95% confidence interval [CI]: 1.01–1.61) and susceptibility (OR = 1.29, 95% CI: 1.01–1.63) of children could be the causes of discrepancy in hesitancy for themselves and for their children. Parents who hesitated to vaccinate themselves might also be hesitated to vaccinate their children (β = 0.077, P

BackgroundSevere fever with thrombocytopenia syndrome (SFTS) has become a significant public health issue in Jinan City. However, the analysis of epidemiological characteristics and spatio-temporal clustering of SFTS in Jinan has not been studied yet.MethodsSFTS data from 2018-2022 in Jinan City were obtained from the China Information System for Disease Control and Prevention. Global spatial autocorrelation and local spatial autocorrelation analyses were performed using ArcGIS 10.2 software, and spatiotemporal hotspot area detection was carried out using SatScan 9.6 software.ResultsBetween 2018 and 2022, 680 SFTS cases were reported in Jinan City, resulting in 53 deaths and an average case fatality rate of 7.8%. 99.0% of cases occurred between April and October, 91.9% individuals were over 50 years old, and 87.79% were primarily farmers. A positive spatial correlation of SFTS in Jinan was observed (Moran's I value between 0.135-0.197, PConclusionSpatial and temporal aggregation of SFTS is evident in Jinan. Based on the spatial and temporal distribution and epidemiological characteristics, prevention and control measures such as public education, monitoring, and training should target key populations in high-incidence epidemic areas.

Objective: To evaluate the preference of primary HCWs and residents on vaccination consultation in community health services to provide evidence for vaccine hesitancy intervention strategies. Methods: A discrete choice model (DCM) was constructed to evaluate the preference difference between primary HCWs and residents on vaccination consultation in community health services in China during May–July 2022. Results: A total of 282 residents and 204 HCWs were enrolled in this study. The residents preferred consulting with an HCW-led approach (β = 2.168), with specialized content (β = 0.954), and accompanied by telephone follow-up (β = 1.552). In contrast, the HCWs preferred face-to-face consultation (β = 0.540) with an HCW-led approach (β = 0.458) and specialized content (β = 0.409), accompanied by telephone follow-up (β = 0.831). College residents and residents with underlying self-reported disease may be near-critically inclined to choose traditional consultation (an offline, face-to-face consultation with standardized content and more prolonged duration) rather than a new-media consulting group (an online consultation with specialized content within 5 min). Urban HCWs preferred long-term consultation groups (the resident-led offline consultation with follow-up lasting more than 5 min). In contrast, rural HCWs preferred efficient consultation (the HCW-led, short-duration, standardized offline consultation mode). Conclusion: The selection preference for vaccine consultation reveals a gap between providers and demanders, with different groups exhibiting distinct preferences. Identifying these targeted gaps can help design more acceptable and efficient interventions, increasing their likelihood of success and leading to better resource allocation for policymakers to develop targeted vaccination policies.

Objective To explore the status quo and influencing factors of knowledge, attitude and practice of voluntary blood donation among undergraduates in Beijing. Methods A questionnaire was designed on the basis of literature, using the method of convenience sampling to survey the undergraduates from 39 universities in Beijing. The t-test, analysis of variance and χ2 test were used to compare the differences in knowledge, attitude and practice of voluntary blood donation among different groups, and logistic regression model was performed to analyze the influencing factors. Results A total of 1 075 valid questionnaires were collected from undergraduates of 39 universities in Beijing. The results showed that the proportion of the participants who had good knowledge about voluntary blood donation was 69.21% (744/1 075). No statistically significant difference was noticed on the scores of voluntary blood donation knowledge between males and females (P>0.05). The scores of voluntary blood donation knowledge of medical students were higher than those of other subjects (P0.05). The rate of medical students’ intention to donate blood was higher than that of other subjects (P

Introduction Human papillomavirus (HPV) infection is the most common sexually transmissible infection worldwide. Although the prevalence of cervical HPV infection has been extensively reported in women worldwide, few epidemiological studies have examined the prevalence of non-cervical HPV infection among both women and men, especially in China.Methods and analysis PROGRESS-Plus is a national, multisite, cross-sectional study that aims to estimate the prevalence of non-cervical HPV infection in women and men aged 18–60 years residing in mainland China. More specifically, PROGRESS-Plus will estimate the prevalence rate of HPV DNA in oral samples from both women and men, and that of anogenital samples from men. The secondary study objectives are to (1) report the aforementioned prevalence rates by HPV genotype, age and geographical region, (2) examine the concordance (ie, prevalence of the same HPV genotype) between the oral and anogenital samples among men, (3) explore risk factors associated with oral (in both women and men) and anogenital (in men only) HPV infection and (4) describe study participants’ health-related quality of life, health behaviour, sexual behaviour and health status.Ethics and dissemination The study protocol and all required documents have been submitted for review and approval to the Independent Ethics Committees of all the participating sites. All participants will provide their written informed consent on study entry, and all the recorded data will be treated as confidential.

Abstract Antibody-dependent cellular cytotoxicity (ADCC) responses to viral infection are a form of antibody regulated immune responses mediated through the Fc fragment. Whether severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) triggered ADCC responses contributes to COVID-19 disease development is currently not well understood. To understand the potential correlation between ADCC responses and COVID-19 disease development, we analyzed the ADCC activity and neutralizing antibody response in 255 individuals ranging from asymptomatic to fatal infections over 1 year post disease. ADCC was elicited by 10 days post-infection, peaked by 11–20 days, and remained detectable until 400 days post-infection. In general, patients with severe disease had higher ADCC activities. Notably, patients who had severe disease and recovered had higher ADCC activities than patients who had severe disease and deceased. Importantly, ADCC activities were mediated by a diversity of epitopes in SARS-COV-2-infected mice and induced to comparable levels against SARS-CoV-2 variants of concern (VOCs) (B.1.1.7, B.1.351, and P.1) as that against the D614G mutant in human patients and vaccinated mice. Our study indicates anti-SARS-CoV-2 ADCC as a major trait of COVID-19 patients with various conditions, which can be applied to estimate the extra-neutralization level against COVID-19, especially lethal COVID-19.

Abstract Over 40% of the coronavirus disease 2019 (COVID-19) COVID-19 patients were asymptomatically infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the immune responses of these asymptomatic individuals is a critical factor for developing the strategy to contain the COVID-19 pandemic. Here, we determined the viral dynamics and antibody responses among 143 asymptomatic individuals identified in a massive screening of more than 5 million people in eight districts of Wuhan in May 2020. Asymptomatic individuals were admitted to the government-designated centralized sites in accordance with policy. The incidence rate of asymptomatic infection is ~2.92/100,000. These individuals had low viral copy numbers (peaked at 315 copies/mL) and short-lived antibody responses with the estimated diminish time of 69 days. The antibody responses in individuals with persistent SARS-CoV-2 infection is much longer with the estimated diminish time of 257 days. These results imply that the immune responses in the asymptomatic individuals are not potent enough for preventing SARS-CoV-2 re-infection, which has recently been reported in recovered COVID-19 patients. This casts doubt on the efficacy of forming “herd-immunity” through natural SARS-CoV-2 infection and urges for the development of safe and effective vaccines.

(1) Background: To explore the influencing factors of human papillomavirus (HPV) vaccination among mothers and daughters so as to provide evidence and strategies for improving the HPV vaccination rate of 9–18-years-old girls. (2) A questionnaire survey was conducted among the mothers of 9–18-year-old girls from June to August 2022. The participants were divided into the mother and daughter vaccinated group (M1D1), the mother-only vaccinated group (M1D0), and the unvaccinated group (M0D0). Univariate tests, the logistic regression model, and the Health Belief Model (HBM) were employed to explore the influencing factors. (3) Results: A total of 3004 valid questionnaires were collected. According to the regions, Totally 102, 204, and 408 mothers and daughters were selected from the M1D1, M1D0, and M0D0 groups, respectively. The mother having given her daughter sex education (OR = 3.64; 95%CI 1.70, 7.80), the mother’s high perception of disease severity (OR = 1.79; 95%CI 1.02, 3.17), and the mother’s high level of trust in formal information (OR = 2.18; 95%CI 1.26, 3.78) were all protective factors for both the mother and her daughter’s vaccination. The mother’s rural residence (OR = 0.51; 95%CI 0.28, 0.92) was a risk factor for vaccination of both mother and daughter. The mother’s education of high school or above (OR = 2.12; 95%CI 1.06, 4.22), the mother’s high level of HPV and HPV vaccine knowledge (OR = 1.72; 95%CI 1.14, 2.58), and the mother’s high level of trust in formal information (OR = 1.72; 95%CI 1.15, 2.57) were protective factors of mother-only vaccination. The older the mother (OR = 0.95; 95%CI 0.91, 0.99) was classed as a risk factor for mother-only vaccination. “Waiting until the daughters are older to receive the 9-valent vaccine” is the main reason why the daughters of M1D0 and M0D0 are not vaccinated”. (4) Chinese mothers had a high willingness to vaccinate their daughters with the HPV vaccine. The higher education level of the mother, giving sex education to the daughter, the older ages of mothers and daughters, the mother’s high level of HPV and HPV vaccine knowledge, a high level of perception of the disease severity, and a high level of trust in formal information were promoting factors of HPV vaccination for mother and daughter, and rural residence was a risk factor to vaccination. To promote HPV vaccination in girls from 9–18 years old, communities could provide health education to rural mothers with low education levels; the government could advocate for HPV vaccination through issuing policy documents; and doctors and the CDC could popularize the optimal age for HPV vaccination to encourage mothers to vaccinate their daughters at the age of 9–14 years old.

Introduction: As a consequence of habitat loss and degradation, the leopard cat (Prionailurus bengalensis) in China has become endangered and in need of urgent protection. In situ conservation of leopard cats must be based on an understanding of their habitat selection patterns. We studied the summer habitat of leopard cats using line-transect surveys in the northern Taihang Mountain region surrounding Beijing, China. We compared used plots with non-used plots in elevation, tree canopy, and 20 other ecological variables, and used Vanderploeg＆Scavia’s resource selection index (VSI) to analyze habitat preferences. Outcomes/others: Results show that tree canopy, tree height, tree density, and stump quantity of used plots were significantly lower than non-used plots in summer, and that leopard cats preferred habitats located on northern, flat slopes with lower slope, shrub-dominated, dry soil, and less fallen-wood. Leopard cats had a strong tendency to use habitats near human disturbance areas with moderate levels of disturbance intensity. Conclusion: The results suggest that future conservation efforts should emphasize: (1) strengthening the protection and management of forest fringe shrub habitats to improve summer habitat suitability, and (2) environmental education and animal protection campaigns to promote community biodiversity conservation.

(1) Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines were developed in only a short amount of time and were widely distributed. We conducted this meta-analysis to understand the safety of SARS-CoV-2 vaccines. (2) Methods: We searched the corresponding literature published from 1 January 2020 to 20 October 2021. Information of adverse events (AEs) of each selected work was collected. The quality and bias of studies was evaluated, and meta-analysis was carried out by using Stata 17.0. (3) Results: Totally, 11,451 articles were retrieved, and 53 of them were included for analysis. The incidence rate of AEs was 20.05–94.48%. The incidence rate of vascular events increased after viral vector vaccination, while the incidence rate of vascular events decreased after mRNA vaccination. Viral vector vaccine had a higher AE rate compared to mRNA vaccines and inactivated vaccines. In most circumstances, the incidence of AEs was higher in older people, female and after the second dose. The sensitivity of meta-analysis was acceptable; however, the literature was subject to a certain publication bias. (4) Conclusions: The safety of SARS-CoV-2 vaccines was acceptable. The incidence of allergic symptoms and cardiovascular and cerebrovascular symptoms was low. Viral vector vaccine had a higher risk of leading to thrombosis events. The understanding of SARS-CoV-2 vaccine AEs should be enhanced, so as to promote the vaccination.

Background: Vaccination is considered the most effective and economical measure for controlling infectious diseases. Although combination vaccines are widely used worldwide, whether any of the combination vaccines is superior to each separate vaccine has yet to be established. This systematic review and meta-analysis aimed to summarize the available evidence on the effectiveness and safety of combination vaccines in children. Methods: A systematic search was conducted from database inception to August 20, 2021, in MEDLINE, Embase, Cochrane, and Scopus. Published randomized clinical trials (RCTs) and open-label trials of immunogenicity and safety of combined vaccines were selected. The results of the studies were quantitatively synthesized. Results: Overall, 25 articles met the inclusion criteria and were included in the meta-analysis. The results indicated that the combined diptheria–tetanus–acellular pertussis (DTaP)–hepatitis B virus (HBV)–Haemophilus influenzae type B (Hib) vaccine group had lower levels of anti-tetanus antibodies than the combined DTaP–HBV and separate Hib vaccinations group (SMD = −0.23; 95% CI: −0.42, −0.05; p = 0.013). Meanwhile, the combined DTaP–HBV–inactivated polio virus (IPV)–Hib vaccine group had higher levels of anti-pertussis (PT) and anti-filamentous hemagglutinin (FHA) antibodies than the combined DTaP–IPV–Hib and separate HBV vaccinations group (anti-PT: SMD = 0.60; 95% CI: 0.45, 0.75; p < 0.0001; anti-FHA: SMD = 0.40; 95% CI: 0.01, 0.78; p = 0.042). The levels of anti-pertactin (PRN) antibodies were lower in the combined DTaP–IPV–Hib vaccine group than in the combined DTaP–IPV and separate Hib vaccinations group (SMD = −0.13; 95% CI: −0.27, −0.00; p = 0.047). The individuals injected with the DTaP–HBV–IPV–Hib vaccine had a lower risk of pain and swelling than those injected with the combined DTaP–HBV–IPV and separate Hib vaccines (pain: RR = 0.79; 95% CI: 0.69, 0.91; p = 0.001; swelling: RR = 0.87; 95% CI: 0.78, 0.98; p = 0.020). However, the group that received the DTaP–HBV–IPV–Hib vaccine had a higher risk of fever than the group that received DTaP–HBV–IPV and separate Hib vaccinations (RR = 1.13; 95% CI: 1.02, 1.26; p = 0.021). Conclusions: This meta-analysis suggests that the combined vaccines (DTaP–IPV–Hib, DTaP–HBV–Hib, DTaP–HBV–IPV–Hib) are safe, well-tolerated, and provide immunogenic alternatives to separate vaccines in children. The combined DTaP–HBV–IPV–Hib vaccine showed a higher incidence of fever, which was lower than the cumulative incidence of fever induced by all vaccines. Future studies should evaluate the cost-effectiveness of using combined vaccines and compare the potency of different formulations to improve routine local or national childhood immunization programs.

Abstract Background Previous studies have demonstrated the role of N6-methyladenosine (m6A) RNA methylation in various biological processes, our research is the first to elucidate its specific impact on LCAT mRNA stability and adipogenesis in poultry. Results The 6 100-day-old female chickens were categorized into high (n = 3) and low-fat chickens (n = 3) based on their abdominal fat ratios, and their abdominal fat tissues were processed for MeRIP-seq and RNA-seq. An integrated analysis of MeRIP-seq and RNA-seq omics data revealed 16 differentially expressed genes associated with to differential m6A modifications. Among them, ELOVL fatty acid elongase 2 (ELOVL2), pyruvate dehydrogenase kinase 4 (PDK4), fatty acid binding protein 9 (PMP2), fatty acid binding protein 1 (FABP1), lysosomal associated membrane protein 3 (LAMP3), lecithin-cholesterol acyltransferase (LCAT) and solute carrier family 2 member 1 (SLC2A1) have ever been reported to be associated with adipogenesis. Interestingly, LCAT was down-regulated and expressed along with decreased levels of mRNA methylation methylation in the low-fat group. Mechanistically, the highly expressed ALKBH5 gene regulates LCAT RNA demethylation and affects LCAT mRNA stability. In addition, LCAT inhibits preadipocyte proliferation and promotes preadipocyte differentiation, and plays a key role in adipogenesis. Conclusions In conclusion, ALKBH5 mediates RNA stability of LCAT through demethylation and affects chicken adipogenesis. This study provides a theoretical basis for further understanding of RNA methylation regulation in chicken adipogenesis.

ABSTRACT: Mesenchymal stem cells can differentiate into adipocyte precursor cells, and the balance of stem cell differentiation determines the quantity of adipocytes. Early-stage adipose tissue expression profiling revealed abnormal expression of DKK3 in the high-fat group. Moreover, DKK3 is enriched in the Wnt/β-catenin signaling pathway, and studies have shown that DKK3 can serve as a gene involved in early regulation of adipogenesis. Therefore, this study focuses on exploring how DKK3 regulates the molecular mechanism of adipocyte differentiation through the Wnt/β-catenin signaling pathway. In this experiment, the role of DKK3 in the differentiation of bone marrow mesenchymal stem cells into adipocyte precursors was validated using in vitro cultured chicken bone marrow mesenchymal stem cells. The results showed that overexpression of DKK3 led to a significant downregulation of Wnt/β-catenin signaling pathway-related marker gene expression (P < 0.05), a significant upregulation of adipogenic differentiation-related genes (P < 0.05), an increase in lipid droplet content, a significant increase in OD value (P < 0.05), a significant upregulation of mitochondrial oxidative respiratory-related marker gene expression (P < 0.05), and a significant downregulation of mitochondrial autophagy-related marker genes (P < 0.05). Conversely, the results were opposite after interfering with DKK3 gene expression. In this study, 4 SNP sites, including g.8419139, g.8419556, g.8419560, and g.8419598, were detected in the 7th exon of DKK3, among which the g.8419598 (C > T) site was significantly correlated with abdominal fat weight and abdominal fat rate in 100-day-old Ma Huang chickens (P < 0.001).

Light is a key environmental factor regulating reproduction in avians. However, the mechanism of light intensity regulating ovarian development is still unclear. In this study, 5-week-old (5 wk) partridge broiler breeders were randomly divided into a low-light-intensity group (LL group) and a natural-light-intensity group (NL group) (n = 100). In the rearing period (5 wk to 22 wk), the light intensity of the LL group and NL group were 0.41 ± 0.05 lux and 45.39 ± 1.09 lux, and in the laying period (23 wk to 32 wk) they were 23.92 ± 0.06 lux and 66.93 ± 0.76 lux, respectively. Samples were collected on 22 wk and 32 wk. The results showed that the LL group had a later age at first egg and a longer laying period than the NL group. Serum P4 and LH levels in the LL group were higher than in the NL group on 22 wk (p < 0.05). On 32 wk, P4, E2, LH and FSH levels in the LL group were lower than in the NL group (p < 0.05). Ovarian transcriptomics and metabolomics identified 128 differentially expressed genes (DEGs) and 467 differential metabolites (DMs) on 22 wk; 155 DEGs and 531 DMs on 32 wk between two groups. An enrichment analysis of these DEGs and DMs identified key signaling pathways, including steroid hormone biosynthesis, neuroactive ligand-receptor interaction. In these pathways, genes such as CYP21A1, SSTR2, and NPY may regulate the synthesis of metabolites, including tryptamine, triglycerides, and phenylalanine. These genes and metabolites may play a dominant role in the light-intensity regulation of ovarian development and laying performance in broiler breeders.

ABSTRACT: Investigations into the association between chicken traits and genetic variations provide helpful breeding information to improve production performance and economic benefits in chickens. The single nucleotide polymorphism technique is an important method in agricultural molecular breeding. In this study, we detected 11 SNPs in the CD36 gene, 2 SNPs (g.-1974 A>G, g.-1888 T>C) located in the 5′ flanking regions, 8 SNPs (g.23496 G>A, g.23643 C>T, g.23931 T>C, g.23937 G>A, g.31256 C>A, g.31258 C>T, g.31335 C>T, g.31534 A>C) located in the intron region, 1 SNPs (g.23743 G>T) located in the exon region and it belongs to synonymous mutation. In SNPs g.23743 G>T, the abdominal fat weight and abdominal fat weight rate of the GG genotype were lower than that of the TT genotype. In SNPs g.23931 T>C, the full-bore weight rate and half-bore weight rate of the TT genotype were higher compared with the CC genotype. And the SNPs g.-1888 T>C, g.23496 G>A, g.23643 C>T, g.31335 C>T and g.31534 A>C were significantly associated with skin yellowness traits, the cloacal skin yellowness before slaughter of the TT genotype was higher than that of the TC and CC genotype in SNPs g.-1888 T>C. Furthermore, 3 haplotypes of the above eleven SNPs were calculated and they correlated with heart weight, stomach weight, wing weight, leg skin yellowness and shin skin yellowness before slaughter. Finally, the CD36 expression profile displayed the expression pattern of CD36 mRNA variation in different tissues.

IntroductionExcessive fat deposition in chickens can lead to reduced feed utilization and meat quality, resulting in significant economic losses for the broiler industry. Therefore, reducing fat deposition has become an important breeding objective in addition to achieving high broiler weight, growth rate, and feed conversion efficiency. In our previous studies, we observed high expression of Regulators of G Protein Signaling 16 Gene (RGS16) in high-fat individuals. This led us to speculate that RGS16 might be involved in the process of fat deposition in chickens.MethodsThus, we conducted a polymorphism and functional analysis of the RGS16 gene to investigate its association with fat-related phenotypic traits in chickens. Using a mixed linear model (MLM), this study explored the relationship between RGS16 gene polymorphisms and fat-related traits for the first time. We identified 30 SNPs of RGS16 in a population of Wens Sanhuang chickens, among which 8 SNPs were significantly associated with fat-related traits, including sebum thickness (ST), abdominal fat weight (AFW), and abdominal fat weight (AFR). Furthermore, our findings demonstrated that AFW, AFR, and ST showed significant associations with at least two or more out of the eight identified SNPs of RGS16. We also validated the role of RGS16 in ICP-1 cells through various experimental methods, including RT-qPCR, CCK- 8, EdU assays, and oil red O staining.ResultsOur functional validation experiments showed that RGS16 was highly expressed in the abdominal adipose tissue of high-fat chickens and played a critical role in the regulation of fat deposition by promoting preadipocyte differentiation and inhibiting their proliferation. Taken together, our findings suggest that RGS16 polymorphisms are associated with fat-related traits in chickens. Moreover, the ectopic expression of RGS16 could inhibit preadipocyte proliferation but promote preadipocyte differentiation.DiscussionBased on our current findings, we propose that the RGS16 gene could serve as a powerful genetic marker for marker-assisted breeding of chicken fat-related traits.

Abstract Background Adipose tissue is an important endocrine and energy-storage organ in organisms, and it plays a crucial role in the energy-metabolism balance. Previous studies have found that sex-linked dwarf (SLD) chickens generally have excessively high abdominal fat deposition during the growing period, which increases feeding costs. However, the underlying mechanism of this fat deposition during the growth of SLD chickens remains unknown. Results The Oil Red O staining showed that the lipid-droplet area of SLD chickens was larger than that of normal chickens in E15 and 14d. Consistently, TG content in the livers of SLD chickens was higher than that of normal chickens in E15 and 14d. Further, lower ΔΨm and lower ATP levels and higher MDA levels were observed in SLD chickens than normal chickens in both E15 and 14d. We also found that overexpression of GHR reduced the expression of genes related to lipid metabolism (AMPK, PGC1α, PPARγ, FAS, C/EBP) and oxidative phosphorylation (CYTB, CYTC, COX1, ATP), as well as reducing ΔΨm and ATP levels and increasing MDA levels. In addition, overexpression of GHR inhibited fat deposition in CPPAs, as measured by Oil Red O staining. On the contrary, knockdown of GHR had the opposite effects in vitro. Conclusions In summary, we demonstrate that GHR promotes mitochondrial function and inhibits lipid peroxidation as well as fat deposition in vivo and in vitro. Therefore, GHR is essential for maintaining the stability of lipid metabolism and regulating mitochondrial function in chicken.

Abstract Background Transmembrane proteins are vital for intercellular signalling and play important roles in the control of cell fate. However, their physiological functions and mechanisms of action in myogenesis and muscle disorders remain largely unexplored. It has been found that transmembrane protein 182 (TMEM182) is dramatically up‐regulated during myogenesis, but its detailed functions remain unclear. This study aimed to analyse the function of TMEM182 during myogenesis and muscle regeneration. Methods RNA sequencing, quantitative real‐time polymerase chain reaction, and immunofluorescence approaches were used to analyse TMEM182 expression during myoblast differentiation. A dual‐luciferase reporter assay was used to identify the promoter region of the TMEM182 gene, and a chromatin immunoprecipitation assay was used to investigate the regulation TMEM182 transcription by MyoD. We used chickens and TMEM182‐knockout mice as in vivo models to examine the function of TMEM182 in muscle growth and muscle regeneration. Chickens and mouse primary myoblasts were used to extend the findings to in vitro effects on myoblast differentiation and fusion. Co‐immunoprecipitation and mass spectrometry were used to identify the interaction between TMEM182 and integrin beta 1 (ITGB1). The molecular mechanism by which TMEM182 regulates myogenesis and muscle regeneration was examined by Transwell migration, cell wound healing, adhesion, glutathione‐S‐transferse pull down, protein purification, and RNA immunoprecipitation assays. Results TMEM182 was specifically expressed in skeletal muscle and adipose tissue and was regulated at the transcriptional level by the myogenic regulatory factor MyoD1. Functionally, TMEM182 inhibited myoblast differentiation and fusion. The in vivo studies indicated that TMEM182 induced muscle fibre atrophy and delayed muscle regeneration. TMEM182 knockout in mice led to significant increases in body weight, muscle mass, muscle fibre number, and muscle fibre diameter. Skeletal muscle regeneration was accelerated in TMEM182‐knockout mice. Furthermore, we revealed that the inhibitory roles of TMEM182 in skeletal muscle depend on ITGB1, an essential membrane receptor involved in cell adhesion and muscle formation. TMEM182 directly interacted with ITGB1, and this interaction required an extracellular hybrid domain of ITGB1 (aa 387–470) and a conserved region (aa 52–62) within the large extracellular loop of TMEM182. Mechanistically, TMEM182 modulated ITGB1 activation by coordinating the association between ITGB1 and laminin and regulating the intracellular signalling of ITGB1. Myogenic deletion of TMEM182 increased the binding activity of ITGB1 to laminin and induced the activation of the FAK‐ERK and FAK‐Akt signalling axes during myogenesis. Conclusions Our data reveal that TMEM182 is a novel negative regulator of myogenic differentiation and muscle regeneration.

Prolactin (PRL) and growth hormone (GH) exhibit important roles in the immune system maintenance. In poultry, PRL mainly plays its roles in nesting, hatching, and reproduction, while GH is primarily responding to body weight, fat formation and feed conversion. In this review, we attempt to provide a critical overview of the relationship between PRL and GH, PRLR and GHR, and the immune response of poultry. We also propose a hypothesis that PRL, GH and their receptors might be used by viruses as viral receptors. This may provide new insights into the pathogenesis of viral infection and host immune response.

Abstract Background B-cell CLL/lymphoma 6 (BCL6) is a transcriptional master regulator that represses more than 1200 potential target genes. Our previous study showed that a decline in blood production in runting and stunting syndrome (RSS) affected sex-linked dwarf (SLD) chickens compared to SLD chickens. However, the association between BCL6 gene and hematopoietic function remains unknown in chickens. Methods In this study, we used RSS affected SLD (RSS-SLD) chickens, SLD chickens and normal chickens as research object and overexpression of BCL6 in hematopoietic stem cells (HSCs), to investigate the effect of the BCL6 on differentiation and development of HSCs. Results The results showed that comparison of RSS-SLD chickens with SLD chickens, the BCL6 was highly expressed in RSS-SLD chickens bone marrow. The bone marrow of RSS-SLD chickens was exhausted and red bone marrow was largely replaced by yellow bone marrow, bone density was reduced, and the levels of immature erythrocytes in peripheral blood were increased. At the same time, the hematopoietic function of HSCs decreased in RSS-SLD chickens, which was manifested by a decrease in the hematopoietic growth factors (HGFs) EPO, SCF, TPO, and IL-3, as well as hemoglobin α1 and hemoglobin β expression. Moreover, mitochondrial function in the HSCs of RSS-SLD chickens was damaged, including an increase in ROS production, decrease in ATP concentration, and decrease in mitochondrial membrane potential (ΔΨm). The same results were also observed in SLD chickens compared with normal chickens; however, the symptoms were more serious in RSS-SLD chickens. Additionally, after overexpression of the BCL6 in primary HSCs, the secretion of HGFs (EPO, SCF, TPO and IL-3) was inhibited and the expression of hemoglobin α1 and hemoglobin β was decreased. However, cell proliferation was accelerated, apoptosis was inhibited, and the HSCs entered a cancerous state. The function of mitochondria was also abnormal, ROS production was decreased, and ATP concentration and ΔΨm were increased, which was related to the inhibition of apoptosis of stem cells. Conclusions Taken together, we conclude that the high expression of BCL6 inhibits the differentiation and development of HSCs by affecting mitochondrial function, resulting in impaired growth and development of chickens. Moreover, the abnormal expression of BCL6 might be a cause of the clinical manifestations of chicken comb, pale skin, stunted growth and development, and the tendency to appear RSS in SLD chickens.

Growth hormone receptor (GHR) can activate several signaling pathways after binding to growth hormone (GH) to regulate cell growth and development. Sex-linked dwarf (SLD) chickens, normal protein functions are prevented because of exon mutations in the GHR gene, have more severe fat deposition. However, the specific molecular mechanisms responsible for this phenotype remains unclear. We therefore investigated the effect of the GHR gene on adipogenic differentiation of chicken bone marrow mesenchymal stem cells (BMSCs). We found that bone marrow fat deposition was more severe in SLD chickens compared to normal chickens, and the expression of genes related to adipogenic differentiation was enhanced in SLD chicken BMSCs. We also detected enhanced mitochondrial function of BMSCs in SLD chickens. In vitro, overexpression of GHR in chicken BMSCs increased mitochondrial membrane potential but decreased reactive oxygen and ATP contents, oxidative phosphorylation complex enzyme activity, and mitochondrial number. Expression of genes associated with mitochondrial biogenesis and function was repressed during adipogenic differentiation in chicken BMSCs, the adipogenic differentiation capacity of chicken BMSCs was also repressed. With knockdown of GHR, opposite results were observed. We concluded that GHR inhibited adipogenic differentiation of chicken BMSCs by suppressing mitochondrial biogenesis and mitochondrial function.

Lipid biosynthesis is a complex process, which is regulated by multiple factors including lncRNA. However, the role of lncRNA in chicken abdominal fat accumulation is still unclear. In this research, we collected liver tissues from six high abdominal fat rate Sanhuang broilers and six low abdominal fat rate Sanhuang broilers to perform lncRNA sequencing and small RNA sequencing. A total of 2,265 lncRNAs, 245 miRNAs, and 5,315 mRNAs were differently expressed. Among of them, 1,136 differently expressed genes were enriched in the metabolic process. A total of 36 differently expressed genes, which were considered as differently expressed lncRNAs’ targets, were enriched in the metabolic process. In addition, we also found out that eight differently expressed miRNAs could target 19 differently expressed genes. FNIP2 and PEX5L were shared in a cis-regulatory network and a differently expressed miRNA target relationship network. LncRNA-FNIP2/miR-24-3p/FNIP2 axis was considered as a potential candidate that may participate in lipid synthesis. Experimentally, the objective reality of lncRNA-FNIP2/miR-24-3p/FNIP2 axis was clarified and the regulation effect of lncRNA-FNIP2/miR-24-3p/FNIP2 axis on synthesis was validated. In brief, our study reveals a potential novel regulatory mechanism that lncRNA-FNIP2/miR-24-3p/FNIP2 axis was considered as being involved in lipid synthesis during chicken adipogenesis in liver.

Skin color is an important economic trait in meat-type chickens. A uniform bright skin color can increase the sales value of chicken. Chickens with bright yellow skin are more popular in China, especially in the broiler market of South China. However, the skin color of chickens can vary because of differences in breeds, diet, health, and individual genetics. To obtain greater insight into the genetic factors associated with the process of skin pigmentation in chickens, we used a colorimeter and high-resolution skin photographs to measure and analyze the skin color of chickens. By analyzing 534 chickens of the same breed, age, and feed condition, we found that the yellowness values of the chickens varied within this population. A significant positive correlation was found between the cloacal skin yellowness values before and after slaughter, and the cloacal skin yellowness value of live chickens was positively correlated with the overall body skin yellowness value. Additionally, chicken skin yellowness exhibited low heritability, ranging from 0.07 to 0.27. Through RNA sequencing, 882 genes were found to be differentially expressed between the skin with the highest and lowest yellowness values. Some of these differentially expressed genes may play an important role in yellow pigment deposition in chicken skin, which included TLR2B, IYD, SMOC1, ALDH1A3, CYP11A1, FHL2, TECRL, ACACB, TYR, PMEL, and GPR143. In addition, we found that the expression and variations of the BCO2 gene, which is referred to as the yellow skin gene, cannot be used to estimate the skin yellowness value of chickens in this population. These data will help to further our understanding of chicken skin yellowness and might contribute to the selection of specific chicken strains with consistent skin coloration.

Sex-linked dwarf (SLD) chicken, which is caused by a recessive mutation of the growth hormone receptor (GHR), has been widely used in the Chinese broiler industry. However, it has been found that the SLD chicken has more abdominal fat deposition than normal chicken. Excessive fat deposition not only reduced the carcass quality of the broilers but also reduced the immunity of broilers to diseases. To find out the key genes and the precise regulatory pathways that were involved in the GHR mutation-induced excessive fat deposition, we used high-fat diet (HFD) and normal diet to feed the SLD chicken and normal chicken and analyzed the differentially expressed genes (DEGs) among the four groups. Results showed that the SLD chicken had more abdominal fat deposition and larger adipocytes size than normal chicken and HFD can promote abdominal fat deposition and induce adipocyte hypertrophy. RNA sequencing results of the livers and abdominal fats from the above chickens revealed that many DEGs between the SLD and normal chickens were enriched in fat metabolic pathways, such as peroxisome proliferator-activated receptor (PPAR) signaling, extracellular matrix (ECM)-receptor pathway, and fatty acid metabolism. Importantly, by constructing and analyzing the GHR-downstream regulatory network, we found that suppressor of cytokine signaling 2 (SOCS2) and cytokine-inducible SH2-containing protein (CISH) may involve in the GHR mutation-induced abdominal fat deposition in chicken. The ectopic expression of SOCS2 and CISH in liver-related cell line leghorn strain M chicken hepatoma (LMH) cell and immortalized chicken preadipocytes (ICP) revealed that these two genes can regulate fatty acid metabolism, adipocyte differentiation, and lipid droplet accumulation. Notably, overexpression of SOCS2 and CISH can rescue the hyperactive lipid metabolism and excessive lipid droplet accumulation of primary liver cell and preadipocytes that were isolated from the SLD chicken. This study found some genes and pathways involved in abdominal fat deposition of the SLD chicken and reveals that SOCS2 and CISH are two key genes involved in the GHR mutation-induced excessive fat deposition of the SLD chicken.

To explore the regulatory mechanism of abdominal fat deposition in broilers, 100-day-old Sanhuang chickens (n = 12) were divided into high-fat and low-fat groups, according to the abdominal fat ratio size. Total RNA isolated from the 12 abdominal fat tissues was used for miRNA and mRNA sequencing. Results of miRNA and mRNA sequencing revealed that miR-429-3p was highly expressed in high-fat chicken whereas LPIN1 expression was downregulated. Further, we determined that miR-429-3p promoted preadipocyte proliferation and differentiation, whereas LPIN1 exerted an opposite effect. Notably, we found that the miR-429-3p/LPIN1 axis facilitated PPARγ pathway activation, which is closely associated with the progression of adipogenesis. In conclusion, our results provide evidence that a novel miR-429-3p/LPIN1 axis is involved in the regulation of adipogenesis, which may have a guiding role in the improvement of breeding for abdominal fat traits in broiler chickens.

MicroRNAs (miRNAs) play a critical role in various biological processes through regulation of gene expression post-transcriptionally. Although miRNAs are involved in cell proliferation and differentiation in mammals, few reports regarding the effects of host miRNAs on macrophage activation and differentiation are available in birds. Here, we reported that gga-miR-200b-3p acts as a positive regulator, enhancing macrophage activation and differentiation using an avian model. We found that ectopic expression of gga-miR-200b-3p in HD11 cells enhances the amount of MHC-II-positive cells and promotes the expression of pro-inflammatory cytokines and that gga-miR-200b-3p directly targets monocyte to macrophage differentiation-associated (MMD). The inhibition of MMD by gga-miR-200b-3p enhances the activation and differentiation of HD11 cells and increases the expression of pro-inflammatory cytokines. Collectively, these findings highlight a crucial role of gga-miR-200b-3p in macrophage activation and differentiation in birds.

Runting and stunting syndrome (RSS), which is characterized by low body weight, generally occurs early in life and leads to considerable economic losses in the commercial broiler industry. Our previous study has suggested that RSS is associated with mitochondria dysfunction in sex-linked dwarf (SLD) chickens. However, the molecular mechanism of RSS remains unknown. Based on the molecular diagnostics of mitochondrial diseases, we identified a recessive mutation c. 409G > A (p. Ala137Thr) of Twinkle mitochondrial DNA helicase (TWNK) gene and mitochondrial DNA (mtDNA) depletion in RSS chickens’ livers from strain N301. Bioinformatics investigations supported the pathogenicity of the TWNK mutation that is located on the extended peptide linker of Twinkle primase domain and might further lead to mtDNA depletion in chicken. Furthermore, overexpression of wild-type TWNK increases mtDNA copy number, whereas overexpression of TWNK A137T causes mtDNA depletion in vitro. Additionally, the TWNK c. 409G > A mutation showed significant associations with body weight, daily gain, pectoralis weight, crureus weight, and abdominal fat weight. Taken together, we corroborated that the recessive TWNK c. 409G > A (p. Ala137Thr) mutation is associated with RSS characterized by mtDNA depletion in SLD chicken.

Runting and stunting syndrome (RSS) in chicken are commonly known as “frozen chicken.” The disease is characterized by lower body weight and slow growth and the incidence rate is widely 5%–20% in sex-linked dwarf (SLD) chickens. However, the etiology of RSS in chickens has plagued researchers for several decades. In this study, histopathology studies demonstrated that the hepatocytes of the RSS chickens contain many mitochondria with damaged and outer and inner membrane along with vacuolar hydropic degeneration. No mtDNA mutation was detected, but our microarray data showed that RSS chickens exhibited abnormal expression of genes, many of which are involved in oxidative phosphorylation (OXPHOS) and fatty acid metabolism. In particular, nuclear gene IGF2BP3 was upregulated in RSS chickens' liver cells. The abnormal expression of these genes is likely to impair the OXPHOS, resulting in reduced ATP synthesis in the hepatocytes of the RSS chickens, which may in turn leads to poor weight gain and retarded growth or stunting of chicks. Our findings suggest that mitochondria dysfunction rather than chronic inflammation is responsible for the reduced growth and RSS in SLD chickens. Mutations in GHR have been shown to compromise mitochondrial function in SLD chickens. Since the mitochondrial damage in the RSS chicken is more severe, we suggest that extra genes are likely to be affected to exacerbate the phenotype.