山东某樱桃谷鸭场出现以患鸭短喙、长舌、生长不良为主要特征的疾病,疑似感染鸭短喙与侏儒综合征病毒(duckling short beak and dwarfism syndrome virus,SBDSV)。本研究旨在分离鉴定该病毒,并检测其对樱桃谷鸭的致病性。首先,通过临床...山东某樱桃谷鸭场出现以患鸭短喙、长舌、生长不良为主要特征的疾病,疑似感染鸭短喙与侏儒综合征病毒(duckling short beak and dwarfism syndrome virus,SBDSV)。本研究旨在分离鉴定该病毒,并检测其对樱桃谷鸭的致病性。首先,通过临床症状、病理变化、病料PCR检测,确定感染鸭短喙侏儒综合征病毒。其次,用SPF鸭胚分离培养病毒后,对病毒进行电镜观察和同源性与系统发育树分析,再检测病毒尿囊液EID_(50)。最后,动物回归试验中,给2日龄樱桃谷鸭口服病毒感染鸭胚尿囊液,观察致病特点,以及用PCR和间接免疫荧光试验检测病毒分布。结果显示:SPF鸭胚接毒后96~120 h鸭胚死亡,电镜观察病毒粒子大小为20~50 nm,尿囊液EID_(50)为10^(-4.85)·0.2 mL^(-1)。尿囊液PCR检测SBDSV为阳性,证明从鸭胚中成功分离培养SBDSV。该病例主要临床表现短喙和体重降低,感染后2周内持续排毒,VP 2片段与鸭短喙侏儒综合征病毒序列的相似性为99.8%,表明是由鸭短喙与侏儒综合征病毒感染引起,命名为SBDS-SD株。动物回归试验中,出现短喙、腹泻、体重显著降低等与自然病例相似的临床症状。本试验成功分离到一株鸭短喙与侏儒综合征病毒,并验证其对樱桃谷鸭具有致病性,为该病的进一步研究提供基础。展开更多
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 syn...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 hemoglobinα1 and hemoglobinβexpression.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 hemoglobinα1 and hemoglobinβwas 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 andΔΨm 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.展开更多
基金This work was supported by grants from the Key-Area Research and Development Program of Guangdong Province(Grant No.2020B020222002)the Guangdong Provincial Promotion Project on Preservation and Utilization of Local Breed of Livestock and Poultry,National Natural Science Foundation of China(Grant No.31401046)+1 种基金the China Agriculture Research System(CARS-41-G03)Guangdong Youth Talent Project.
文摘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 hemoglobinα1 and hemoglobinβexpression.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 hemoglobinα1 and hemoglobinβwas 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 andΔΨm 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.
