High expression circRALGPS2 in atretic follicle induces chicken granulosa cell apoptosis and autophagy via encoding a new protein

Background The reproductive performance of chickens mainly depends on the development of follicles.Abnor-mal follicle development can lead to decreased reproductive performance and even ovarian disease among chick-ens.Chicken is the only non-human animal with a high incidence of spontaneous ovarian cancer.In recent years,the involvement of circRNAs in follicle development and atresia regulation has been confirmed.Results In the present study,we used healthy and atretic chicken follicles for circRNA RNC-seq.The results showed differential expression of circRALGPS2.It was then confirmed that circRALGPS2 can translate into a protein,named cir-cRALGPS2-212aa,which has IRES activity.Next,we found that circRALGPS2-212aa promotes apoptosis and autophagy in chicken granulosa cells by forming a complex with PARP1 and HMGB1.Conclusions Our results revealed that circRALGPS2 can regulate chicken granulosa cell apoptosis and autophagy through the circRALGPS2-212aa/PARP1/HMGB1 axis.

Significant genomic introgression from grey junglefowl(Gallus sonneratii)to domestic chickens(Gallus gallus domesticus)

Background Chicken is one of the most numerous and widely distributed species around the world,and many studies support the multiple ancestral origins of domestic chickens.The research regarding the yellow skin phenotype in domestic chickens(regulated by BCO2)likely originating from the grey junglefowl serves as crucial evidence for demonstrating the multiple origins of chickens.However,beyond the BCO2 gene region,much remains unknown about the introgression from the grey junglefowl into domestic chickens.Therefore,in this study,based on wholegenome data of 149 samples including 4 species of wild junglefowls and 13 local domestic chicken breeds,we explored the introgression events from the grey junglefowl to domestic chickens.Results We successfully detected introgression regions besides BCO2,including two associated with growth trait(IGFBP2 and TKT),one associated with angiogenesis(TIMP3)and two members of the heat shock protein family(HSPB2 and CRYAB).Our findings suggest that the introgression from the grey junglefowl may impact the growth performance of chickens.Furthermore,we revealed introgression events from grey junglefowl at the BCO2 region in multiple domestic chicken breeds,indicating a phenomenon where the yellow skin phenotype likely underwent strong selection and was retained.Additionally,our haplotype analysis shed light on BCO2 introgression event from different sources of grey junglefowl into domestic chickens,possibly suggesting multiple genetic flows between the grey junglefowl and domestic chickens.Conclusions In summary,our findings provide evidences of the grey junglefowl contributing to the genetic diversity of domestic chickens,laying the foundation for a deeper understanding of the genetic composition within domestic chickens,and offering new perspectives on the impact of introgression on domestic chickens.

Asymmetric expression of CA2 and CA13 linked to calcification in the bilateral mandibular condyles cause crossed beaks in chickens

Crossed beak is a complex mode of inheritance with prevalence ranging from 0.2 to 7.4% in at least 12 chicken strains worldwide.To reveal the intrinsic factors causing crossed beaks,genes expression patterns in bilateral mandibular condyle between affected and normal birds were characterized by RNA sequencing analysis in the present studies.Crossed beak was induced by short length of unilateral mandibular ramus,and a total of 110differentially expressed genes were up-or down-regulated in the affected(short)mandibular condyle side as compared to the normal side.Carbonic anhydrase 2(CA2)and Carbonic anhydrase 13(CA13)were enriched in the carbonate dehydratase activity,and high-expressed in mandibular condyle and osteoblasts(P<0.05).However,both were low-expressed in short mandibular condyle side of affected birds(P<0.05).The carbonate dehydratase inhibitor experiments confirmed that there is positive association between the calcification and carbonic anhydrase isoenzymes.Quantitative analysis with cetylpyridinium chloride showed a decrease in calcification when the cells were transfected with an anti-CA13 shRNA.Our research suggested that CA2 and CA13 are down-calcified in shortside mandibular condyle,and caused mandibular ramus to grow slowly.CA2 and CA13 have the critical role in crossed beaks by regulating calcification of mandibular condyle.

普洱茶茶渣对茶花鸡2号肉品质的影响

试验旨在探讨饲粮中添加不同水平普洱茶茶渣对茶花鸡2号肉品质的影响。选取144只茶花鸡2号,随机分为3组,每组6个重复,每个重复8只。对照组饲喂基础饲粮,1%和2%茶渣组分别在基础饲粮上添加1%和2%的普洱茶茶渣,试验期28 d,试验结束进行鸡肉品质测定。结果表明:①与对照组相比,1%和2%茶渣组胸肌和腿肌肉品质物理特性(L^(*)值、a^(*)值、b^(*)值、pH4_(5min)、pH_(24h)、失水率、蒸煮损失率、剪切力)和常规营养成分(粗蛋白、粗脂肪和粗灰分含量)无显著差异(P>0.05),1%茶渣组胸肌各氨基酸含量以及2%茶渣组腿肌各氨基酸含量无显著差异(P>0.05)。②与对照组相比,2%茶渣组胸肌Asp、Thr、Ser、Glu、Ala、Cys、Val、Ile、Leu、Tyr、Lys、UAA和TAA含量极显著降低(P<0.01),Met、Phe、His、Arg、SAA、BAA、EAA和NEAA含量显著降低(P<0.05),Gly和Pro含量无显著变化(P>0.05),1%茶渣组腿肌Tyr含量极显著降低(P<0.01),Asp、Thr、Ser、Glu、Ala、Val、Ile、Leu、Phe、Lys、Arg、UAA、SAA、BAA、EAA、NEAA和TAA含量显著降低(P<0.05),Gly、Cys、Met、His和Pro含量无显著变化(P>0.05)。由此可见,饲粮中添加1%和2%普洱茶茶渣分别降低了茶花鸡2号腿肌和胸肌氨基酸含量,降低了肌肉风味。

TIMP2 promotes intramuscular fat deposition by regulating the extracellular matrix in chicken

The interaction between myocytes and intramuscular adipocytes is a hot scientific topic. Using a co-culture system, this study aims to investigate the regulation of intramuscular fat deposition in chicken muscle tissue through the interaction between myocyte and adipocyte and identify important intermediary regulatory factors. Our proteomics data showed that the protein expression of tissue inhibitor of metalloproteinases 2(TIMP2) increased significantly in the culture medium of the co-culture system, and the content of lipid droplets was more in the co-culture intramuscular adipocytes. In addition, TIMP2 was significantly upregulated(P<0.01) in muscle tissue of individuals with high intramuscular fat content.Weighted gene co-expression network analysis revealed that TIMP2 was mainly involved in the extracellular matrix receptor interaction signaling pathway and its expression was significantly correlated with triglyceride, intramuscular fat,C14:0, C14:1, C16:0, C16:1, and C18:1n9C levels. Additionally, TIMP2 was co-expressed with various representative genes related to lipid metabolism(such as ADIPOQ, SCD, ELOVL5, ELOVL7, and LPL), as well as certain genes involved in extracellular matrix receptor interaction(such as COL1A2, COL4A2, COL5A1, COL6A1, and COL6A3), which are also significantly upregulated(P<0.05 or P<0.01) in muscle tissue of individuals with high intramuscular fat content.Our findings reveal that TIMP2 promotes intramuscular fat deposition in muscle tissue through the extracellular matrix receptor interaction signaling pathway.

Expression of B Locus Beta 2 (<i>BLB2</i>) Gene at Cytolytic and Latent Immune Response Stages of Immunocompetence in Nigerian Indigenous Chickens

An economically-important trait in poultry for which gene identification continues to be a challenge is immune response. The objective of the study was to quantitate the expression of major histocompatibility complex (MHC) class II BLB2 gene at cytolytic and latent immune response stages in Nigerian indigenous chickens. A total of 108 Nigerian indigenous chickens (NIC) were sourced across the South-western states in Nigeria. The birds were inoculated with sheep red blood cells (SRBC), after which blood samples were obtained (5 days post-inoculation) and antibody haemagglutination test was carried out to place the birds into groups of high and low antibody titre levels. The categorisation of the birds resulted in six groups of normal feather high, normal feather low, naked neck high, naked neck low, frizzle feather high and frizzle feather low antibody groups. A total of 48 chicks were selected from the progeny for gene expression studies. Surgical excision of thymus and spleen was carried out for the detection of cytolytic and latent responses of the birds. β-actin was used as the endogenous control and the critical threshold method (2–ΔΔCт) was carried out for the determination of fold change. The fold change of spleen tissue expression at cytolytic immune response of the birds was 30,362.44 compared to latent response 294.07;and the fold change of thymus expression at cytolytic immune response of the birds was 51.98 compared to latent response 5.24. At both cytolytic and latent stages of immune response to SRBC antigen, BLB2 expression in the spleen was comparatively higher than in the thymus and the height of transcriptional activity was associated with the cytolytic stage. The birds of high titre at both the cytolytic and the latent responses had higher mRNA expression. This study concluded that BLB2 gene expression in the Nigerian indigenous chicken was induced at the cytolytic stage and repressed at the latent stage. During avian infections, the category of high immune response birds would perform better than the low immune response counterpart;and the protective response that BLB2 gene offers will be repressed from one time point to the other.

H9N2亚型禽流感病毒A／Chicken／Gansu／2／99株基因组的分子特征

目的测定H9N2亚型禽流感病毒A/Chicken/Gansu/2/99(CK/GS/2/99)分离株的基因组序列并与参考毒株进行同源性分析,阐明该毒株的遗传变异及分子特征。方法采集发病鸡泄殖腔样品,经鸡胚尿囊腔接种分离病毒,采用RT-PCR方法对CK/GS/2/99株的8个分节段基因进行扩增,分别将其克隆到pGEM-T easy载体后进行序列测定与同源性分析。结果CK/GS/2/99株PB2、PB1、PA、HA、NP、NA、M、NS基因的开放阅读框分别由2280、2274、2151、1683、1497、1401、759、864个碱基组成,分别编码759、757、716、560、498、466、252/97、231/122个氨基酸残基。该毒株HA上HA1和HA2裂解位点序列为PARSSR↓GLF,具有典型的低致病性禽流感病毒的特征。同源性分析显示,CK/GS/2/99株与1998-2002年间大部分中国大陆分离株遗传关系较近,尤其与CK/NX/4/99和CK/HB/31/00株遗传关系密切。结论CK/GS/2/99与大部分流行于中国内陆的H9N2亚型毒株均来源于共同的祖先毒株CK/BJ/1/94,这为了解中国H9N2亚型禽流感病毒的分子流行病学提供了资料。

鸡白细胞介素-2基因在Pichia methanolica酵母中的表达

鸡白细胞介素-2(chIL-2)是近年来新发现的一种禽类细胞因子.为建立用甲醇型酵母Pichiamethanolica(P.methanolica)表达鸡白细胞介素-2基因(chIL-2)的新途径,将chIL-2基因插入到P.methanolica分泌型表达载体pMETαA构建了重组PMAD11表达菌株(pMETαA/rchIL-2).经SDS-PAGE、Western印迹测定,证实chIL-2基因在P.methanolica中表达成功,rchIL-2的分子量约为16kDa,其表达量占分泌总蛋白的35%.

2个杂交鸡种生长性能比较与生长曲线模型建立

【目的】利用茶花鸡2号E系公鸡、腾冲雪鸡白肉公鸡分别与狄高D系母鸡杂交得到Y系和N系鸡,评定2种杂交后代生长性能,为探究最具优势的杂交后代生长发育规律提供理论参考。【方法】以同日出雏的Y系鸡和N系鸡作为研究对象,测定0~29周龄体重指标,记录生长发育情况;并在60、90和120日龄,随机挑选Y系和N系公鸡和母鸡各30只,测定体尺指标,比较2种鸡的差异及相关性,确定最具优势的杂交后代;利用Logistic、Gompertz和von Bertalanffy等3种非线性生长模型对其不同性别下的体重进行曲线拟合,求得最佳生长曲线模型。【结果】0~29周龄体重生长曲线中,Y系的公鸡体重明显优于N系,Y系的母鸡体重略优于N系。体重和体尺指标测定结果显示,Y系鸡和N系鸡均为公鸡极显著大于母鸡(P<0.01),且同一性别下Y系鸡明显优于N系鸡。用具杂交优势的Y系鸡作生长曲线拟合分析,von Bertalanffy模型拟合值更接近实测值,是Y系鸡最佳生长曲线模型。体重与体尺指标相关分析显示,Y系鸡的体重与胫围间具有较高相关性,因此,可将胫围作为Y系鸡选育的参考标准。【结论】Y系鸡即茶花鸡2号E系公鸡与狄高D系母鸡的杂交改良效果优于N系鸡即腾冲雪鸡白肉公鸡与狄高D系母鸡的杂交改良效果,且von Bertalanffy生长曲线拟合模型能更准确地模拟Y系鸡生长发育规律,确定为最佳生长曲线模型。

Characteristic and mercury adsorption of activated carbon produced by CO_2 of chicken waste

Preparation of activated carbon from chicken waste is a promising way to produce a useful adsorbent for Hg removal. A three-stage activation process （drying at 200℃, pyrolysis in N2 atmosphere, followed by CO2 activation） was used for the production of activated samples. The effects of carbonization temperature （409-4500℃）, activation temperature （700-900℃）, and activation time （1-2.5 h） on the physicochemical properties （weight-loss and BET surface） of the prepared carbon wereinvestigated. Adsorptive removal of mercury from real flue gas onto activated carbon has been studied. The activated carbon from chicken waste has the same mercury capacity as commercial activated carbon （Darco LH） （Hg^v： 38.7% vs. 53.5%, Hg^0： 50.5% vs. 68.8%）, although its surface area is around 10 times smaller, 89.5 m^2/g vs. 862 m^2/g. The low cost activated carbon can be produced from chicken waste, and the procedure is suitable.

白羽肉鸡、茶花鸡、茶花鸡2号肌肉氨基酸含量比较分析

试验旨在比较白羽肉鸡、茶花鸡、茶花鸡2号肌肉氨基酸含量差异,选择达上市日龄的白羽肉鸡、茶花鸡和茶花鸡2号各30只(公、母各半),屠宰后取胸肌和腿肌,制成冻干粉样品,采用高效液相色谱法测定样品的氨基酸含量。结果表明,茶花鸡、茶花鸡2号胸肌和腿肌必需氨基酸(EAA)、苦味氨基酸(BAA)、总氨基酸(TAA)含量显著高于白羽肉鸡(P<0.05);茶花鸡胸肌鲜味氨基酸(UAA)含量显著高于茶花鸡2号(P<0.05),BAA含量显著低于茶花鸡2号(P<0.05);茶花鸡公鸡腿肌EAA、UAA、甜味氨基酸(SAA)、BAA、TAA含量显著高于茶花鸡2号(P<0.05),茶花鸡2号母鸡腿肌EAA、BAA含量显著高于茶花鸡(P<0.05)。性别对茶花鸡胸肌、腿肌和茶花鸡2号腿肌氨基酸含量有显著影响(P<0.05)。3种鸡的必需氨基酸组成模式基本符合人体理想蛋白质的要求,氨基酸比值系数分值(SRC)均在70左右,具有较高的氨基酸营养价值。研究表明,茶花鸡、茶花鸡2号肌肉氨基酸含量优于白羽肉鸡,茶花鸡和茶花鸡2号之间差异较小,茶花鸡略优于茶花鸡2号。

The Study on Correlation Analysis of Single Nucleotide Polymorphism of IGF2 Gene and Body Fatness Traits in Chicken

Insulin-like growth factor Ⅱhas profound effects on the growth and differentiation of animal embryo. Some researches indicated that it affects the fat metabolism of poultry. This study was designed to investigate the effect of IGF2 on chicken fatness traits. Broiler, Hyline Brown layer and three native breeds (Shiqiza, Beijing You, Baier) were used in this research. Body weight and body composition traits were measured in broiler line at the age of 7 weeks. Primers for exon2 in IGF2 were designed from database of chicken genomic sequence. Polymorphisms were detected by PCR-SSCP and DNA sequencing. The total χ2 test results showed that there was a significant difference (P < 0.01) in the frequency of genotype among breeds. A C/G mutation at base position 139 was found among individuals in broiler line and the least square analysis showed that BB genotype birds had significant lower (P <0.05) abdominal fat weight and percentage of abdominal fat than AA or AB genotype birds. From the results we can conclude putatively that IGF2 gene is the major gene affecting the fatness traits of chicken or it links with the major gene, and the mutation could be used as the molecular genetic marker to select the chicken for low abdominal fat.

SWOT Analysis on Agricultural Enterprises Implementing B2C E-commerce——A Case Study of Wuding Strong Chicken Farming Enterprises

This paper first introduced current situations of agricultural enterprises using B2C e-commerce to sell agricultural products.Then,using SWOT method,it analyzed strengths,weaknesses,opportunities,and threats of Wuding strong chicken farming enterprises implementing B2C e-commerce.Finally,it came up with recommendations for Wuding strong chicken farming enterprises implementing B2C e-commerce.

Comparison of Five Expression Vectors for the Ha Gene in Constructing a DNA Vaccine for H6N2 Influenza Virus in Chickens

A number of eukaryotic expression vectors have been developed for use as DNA vaccines. They showed varying abilities to initiate immune responses;however, there is little data to indicate which of these vectors will be the most useful and practical for DNA vaccines in different species. This report examines the use of five expression vectors with different promoters and Kozak sequence to express the same hemagglutinin (HA) protein of an H6N2 avian influenza virus for DNA vaccination in chickens. Although intramuscular vaccination with seven DNA constructs elicited no or limited measurable H6 HA antibody responses in Hy-Line chickens, variable reduction in virus shedding for either oropharyngeal or cloacal swabs post-virus challenge were observed. This indicated that all DNA constructs generated some levels of protective immunity against homologous virus challenge. Interestingly, lower dose (50 or 100 μg) of plasmid DNAs consistently induced better immune response than higher dose (300 or 500 μg). In the transfection experiments there appeared to be a hierarchy in the in vitro expression efficiency in the order of pCAG-optiHAk/ pCAG-HAk > pCI-HAk > VR-HA > pCI-HA > pCI-neo-HA > pVAX-HA. Since the level of in vitro expression correlates with the level of immune response in vivo, in vitro expression levels of the DNA constructs can be used as an indicator for pre-selection of plasmid vaccines prior to in vivo assessment. Moreover, our results suggested that the Kozak sequence could be used as an effective tool for DNA vaccine design.

微生物制剂对冬季鸡舍NH_(3)和CO_(2)浓度的影响

旨在研究微生物制剂改善冬季鸡舍内NH_(3)和CO_(2)浓度。选取鸡舍构造、配套设施、鸡只数量、生长状态、日龄及饲养管理模式相同的2栋鸡舍,一栋鸡舍为对照组,另一栋鸡舍为处理组,分别挑选鸡舍内1、4、7列鸡笼,每列鸡笼分上、中、下3层,每栋鸡舍共设9个处理点,处理点位于鸡笼粪带末端,测量点位于处理点上方5 cm处。试验期间每天中午12:30对处理组每个处理点各喷洒约170 mL的微生物制剂(主要成分为复合乳酸菌、复合芽孢杆菌、复合酶制剂、酵母菌、载体),对照组处理点喷洒相同量的水,同时每天8:30、12:30、16:30对2栋鸡舍的测量点进行CO_(2)、NH_(3)浓度检测。结果显示:在时间维度上,处理组测量点的NH_(3)浓度极显著低于对照组(P<0.01),而处理组测量点的CO_(2)浓度与对照组差异不显著(P>0.05);在空间维度上,处理组1、4、7列测量点的NH_(3)浓度均极显著低于对照组(P<0.01),而处理组1、4、7列测量点的CO_(2)浓度与对照组均无显著差异(P>0.05);处理组上、中、下层测量点的NH_(3)浓度均极显著低于对照组(P<0.01),而处理组上、中层的CO_(2)浓度与对照组均无显著差异(P>0.05)。结果表明,微生物制剂对冬季鸡舍内NH_(3)的产生有明显的抑制作用,但对CO_(2)浓度没有太大影响。研究结果为降低冬季鸡舍内NH_(3)浓度提供了一定参考依据。

Association of Bone Morphogenetic Protein-2 Gene with Skeletal Traits in Chickens

Bone morphogenetic protein-2 （BMP-2） plays a key role in bone formation and maintenance. BMP-2 can stimulate longitudinal bone growth by increasing the growth plate chondrocyte proliferation, hypertrophy, and cartilage matrix synthesis. The current study was designed to investigate the associations of the BMP-2 gene polymorphism with chicken skeletal traits. Northeast Agricultural University F2 resource population was used in this study. Body weight and body composition traits were measured in F2 population. Polymorphism between parental lines was detected by DNA sequencing, and PCR-fragment length polymorphism method was then developed to screen the population. The results showed that the BMP-2 gene polymorphism was associated with skeletal traits in F2 population. This research suggests that BMP-2 gene may be a candidate locus or linked to a major gene that affects skeletal traits in chickens.

Correlation between DRD2 Gene Polymorphism and Early Egg Production Performance of Libo Yaoshan Chicken

To improve egg production performance of local chicken breed in Guizhou Province, Libo Yaoshan chicken, with dopamine receptor 2 （ DRD2 ） as one of the candidate genes, we detected its genetic variation in 196 Libe Yaoshan hens using PCR-SSCP （single-strand conformation polymorphism） and sequencing method, and analyzed the correlation between genetic variation and egg production traits. The results showed that TT and TG genotypes in mRNA SNlX）62 （C→T） loci of the DRD2 gene had extremely significant difference in egg production at 38 weeks age （P 〈0.01 ）, and significant difference in egg weight at 300 days age （P 〈0.05 ）. The single nucleotide polymorphisms （SNPs） mutation induced synonymous mutation of the 312th amino acids （leucine） in DRD2 protein, from L （CTG） to L （TI＇G）. The mRNA SNP962 （C→T） loci had a larger genetic effect on egg production at 38 weeks age, and could be used as a molecular marker in early breeding of Libo Yaoshan chicken.

Correlation between Egg Production Traits and Broodiness Traits in Shiqiza,Langya and Luqin B2 Chickens

[ Objective] To investigate the relationship between the egg production traits and broodiness of Shiqiza, Langya and Luqin B2 chickens. E Method] Three chicken breeds, Shiqiza chickens （a breed preserved by Shandong Academy of Agricultural Sciences）, Langya chickens （a local breed in Shandong Province） and Luqin B2 chickens （a cultivated breed） were selected. Then their broodiness traits were observed and the egg productions were analyzed. Finally, the relationships between the egg production traits and broodiness were analyzed by SAS software. [ Result] The Shiqiza, Langya and Luqin B2. chickens were broody and their broodiness rate was 15.80%, 2.24% and 6.95%, respectively. Compared with the non-broody chickens, the egg productions of Shiqiza, Langya and Luqin B2 chickens were respectively decreased by 17.16%, 1.53% and 10.8% at the age of 43 weeks. The three breeds had significant differences in repeats of broody cycles （ P 〈 0.05）, and extremely significant differences in the broodiness duration, the the first day of broodiness, the age at the first egg, total amount of abnormal eggs and amount of double- yolked eggs （P 〈 0.01 ）. [Conclusion] The broodiness is a main factor affecting egg production traits. The degree of effects of broodiness on egg production traits is decreased successively in Shiqiza chicken, Luqin B2 chicken and Langya chicken.

Cloning Sequencing and Bioinformatics Analysis of GRX2 and TRX2 from Puerpiao chicken and Tengchongxue chicken

[ Objective ] The study was to explore whether glutaredoxin （GRX2） and thioredoxin （TRX2） genes vary between Puerpiao chicken and Tengchongxue chicken in Yunnan Province. [ Methods ] Using Sanhuang chicken as the control, the GRX2 and TRX2 genes were cloned from skirt tissues of Puerp/ao chicken and Tengchongxue chicken and then subjected to bioinformatics analysis. [ Results ] The sequencing results of both the GRX2 and TRX2 genes were completely consistent among Puerp/ao chicken, Tengchongxue chicken and Sanhuang chicken. And the sequences of GRX2 and TRX2 genes share a 100% homology with the results accessed in GenBank, and no any mutation was observed. [ Conclusion] The result provides scientific basis for investigating the antioxidant capacity of different chickens and utilizing elite local chicken resources.

UBE2I stimulates female gonadal differentiation in chicken(Gallus gallus)embryos

Without known analogous sex-determining factors like SRY(sex determining region Y)in mammals,the chicken(Gallus gallus)sex determination mechanism still remains unclear,which highly restricts the biological research on chicken development and poultry single-sex reproduction.Here we not only characterized a new female-biased gene UBE2I and identified the expression pattern by qRT-PCR,but also described the functional role of UBE2I in the gonadal development of chicken embryos.Results showed that UBE2I exhibited a female-biased expression pattern in the early stage of PGCs(primordial germ cells)in embryonic gonads and robust expression in ovaries of newborn chickens.Most importantly,we successfully developed an effective method to interfere or overexpress UBE2I in chicken embryos through the intravascular injection.The qRT-PCR analysis showed that the sex-related genes(FOXL2,CYP19A1 and HINTW)in females were upregulated(P<0.05)under the overexpression of UBE2I and the sex-related genes(SOX9,DMRT1 and WT1)in females were downregulated(P<0.05)after interfering UBE2I.Furthermore,the change of UBE2I expression was associated with the level of estradiol and its receptors(AR and ESR),which suggests that UBE2I is necessary to initiate the female-specific development in chickens.In conclusion,this work demonstrates that UBE2I is a crucial sex differentiation-related gene in the embryonic development of chickens,which provides insights for further understanding the mechanism of sex determination in chickens.