Variants in chicken growth hormone receptor （GHR） gene lead to sex-linked dwarf （SLD） chickens, but effects of different variants are distinct. In this study, 11 SLD chicken breeds or strains including 3 Chinese n...Variants in chicken growth hormone receptor （GHR） gene lead to sex-linked dwarf （SLD） chickens, but effects of different variants are distinct. In this study, 11 SLD chicken breeds or strains including 3 Chinese native breeds and 8 breeding strains were studied in order to investigate the effects of different sex-linked dwarf variations on growth performance. The results showed that there were three reasons which could lead to dwarfism in the 11 breeds or strains. Firstly, an about 1.7 kb deletion of growth hormone receptor （GHR） gene leads to dwarfism in Jiangxi dwarf chicken, strains GF24, GF26, N308, N309, and N310. Secondly, a T354C mutation in exon 5 of the GHR gene leads to dwarfism in strains N301 and N305. Thirdly, an unknown variant leads to dwarfism in Guizhou Yellow Dwarf chicken and Yixing Bantam chicken. In addition, all individuals of N303 had the 1.7 kb deletion of the GHR gene, and additionally, some of them also carried the T354C mutation. As far as the performance of individuals were compared among T354C homozygote, deletion homozygote, and heterozygote carrying both T354C and deletion, it was found that the T354C＇s impacts on body weight of Chinese chickens were maximum, the body weight of chickens with homozygote T354C was 92.12% of those with heterozygote, and the difference of the body weight between deletion homozygote and heterozygote was not significant. There was no significant difference of shank length among three genotypes.展开更多
Background: Interferon-γ(IFN-γ) is critical for innate and adaptive immunity against viral and bacterial infections. IFN-γ reportedly affects the phagocytic ability of monocytes and macrophages as well as regulates...Background: Interferon-γ(IFN-γ) is critical for innate and adaptive immunity against viral and bacterial infections. IFN-γ reportedly affects the phagocytic ability of monocytes and macrophages as well as regulates pituitary function in humans and mice. The present study analyzed the impact of IFN-γ on monocyte and macrophage phagocytosis, production performance, and pituitary function in vivo and in vitro(in dwarf chickens). IFN-γ was injected into dwarf chickens through a vein, and then, the laying rate, average egg weight, and levels of follicle-stimulating hormone(FSH) and IFN-γ were measured in treatment and control groups. For the in vitro experiment, the pituitary tissues were supplemented with IFN-γ, and the m RNA expression levels of follicle-stimulating hormone beta subunit(FSH-β), interferon gamma receptor 1(IFNGR1),and interferon gamma receptor 2(IFNGR2) in the pituitary were assessed.Results: Monocyte and macrophage phagocytosis product(PP) was decreased by IFN-γ treatment in a dose-dependent manner in vitro. In the in vivo experiment, the level of IFN-γ in the treatment group was higher than that in the control group at 7 d(P < 0.05), 14 d(P < 0.01), and 21 d(P < 0.01) post-injection.Compared with the control group, monocyte and macrophage PP was lower in the treatment group after injection(P < 0.01). The laying rate was higher in the treatment group than in the control group at 2 and3 wk post-injection(P < 0.05). There was a significant difference between the treatment and control groups in the levels of FSH at 1, 3, 7, and 14 d post-injection(P < 0.01). In the in vitro experiment, increased m RNA expression levels of FSH-β, IFNGR1, and IFNGR2 were observed in the treatment group after stimulation with100 U/m L IFN-γ for 24 h compared to those in the control group(P < 0.05).Conclusions: IFN-γ inhibited the phagocytosis of monocytes and macrophages; up-regulated the m RNA expression levels of the FSH-β, IFNGR1, and IFNGR2; enhanced the secretion of FSH; and improved the laying rate. IFN-γ might be an important regulator in the trade-off between the immune effect and production performance in dwarf chickens.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projects under the Major State Basic Research Development Program China(2006CB102107)the earmarked fund for Modern Agro-Industry Technology Research System (nycytx-42-G1-04)the National High Technology Research and Development Program of China (863 Program,2010AA10A102)
文摘Variants in chicken growth hormone receptor （GHR） gene lead to sex-linked dwarf （SLD） chickens, but effects of different variants are distinct. In this study, 11 SLD chicken breeds or strains including 3 Chinese native breeds and 8 breeding strains were studied in order to investigate the effects of different sex-linked dwarf variations on growth performance. The results showed that there were three reasons which could lead to dwarfism in the 11 breeds or strains. Firstly, an about 1.7 kb deletion of growth hormone receptor （GHR） gene leads to dwarfism in Jiangxi dwarf chicken, strains GF24, GF26, N308, N309, and N310. Secondly, a T354C mutation in exon 5 of the GHR gene leads to dwarfism in strains N301 and N305. Thirdly, an unknown variant leads to dwarfism in Guizhou Yellow Dwarf chicken and Yixing Bantam chicken. In addition, all individuals of N303 had the 1.7 kb deletion of the GHR gene, and additionally, some of them also carried the T354C mutation. As far as the performance of individuals were compared among T354C homozygote, deletion homozygote, and heterozygote carrying both T354C and deletion, it was found that the T354C＇s impacts on body weight of Chinese chickens were maximum, the body weight of chickens with homozygote T354C was 92.12% of those with heterozygote, and the difference of the body weight between deletion homozygote and heterozygote was not significant. There was no significant difference of shank length among three genotypes.
基金supported by grants from National Natural Science Foundation of China(3157130570)Young Scientist Supporting Project,Program for Changjiang Scholars and Innovative Research Team in University(IRT_15R62)+1 种基金Farm Animals Germplasm Resource Platform,National Transgenic Creature Breeding Grand Project(2016ZX08008-003)Innovation Base Cultivation and Development Project-research on precise genetic modify in sheep(Z171100002217072)
文摘Background: Interferon-γ(IFN-γ) is critical for innate and adaptive immunity against viral and bacterial infections. IFN-γ reportedly affects the phagocytic ability of monocytes and macrophages as well as regulates pituitary function in humans and mice. The present study analyzed the impact of IFN-γ on monocyte and macrophage phagocytosis, production performance, and pituitary function in vivo and in vitro(in dwarf chickens). IFN-γ was injected into dwarf chickens through a vein, and then, the laying rate, average egg weight, and levels of follicle-stimulating hormone(FSH) and IFN-γ were measured in treatment and control groups. For the in vitro experiment, the pituitary tissues were supplemented with IFN-γ, and the m RNA expression levels of follicle-stimulating hormone beta subunit(FSH-β), interferon gamma receptor 1(IFNGR1),and interferon gamma receptor 2(IFNGR2) in the pituitary were assessed.Results: Monocyte and macrophage phagocytosis product(PP) was decreased by IFN-γ treatment in a dose-dependent manner in vitro. In the in vivo experiment, the level of IFN-γ in the treatment group was higher than that in the control group at 7 d(P < 0.05), 14 d(P < 0.01), and 21 d(P < 0.01) post-injection.Compared with the control group, monocyte and macrophage PP was lower in the treatment group after injection(P < 0.01). The laying rate was higher in the treatment group than in the control group at 2 and3 wk post-injection(P < 0.05). There was a significant difference between the treatment and control groups in the levels of FSH at 1, 3, 7, and 14 d post-injection(P < 0.01). In the in vitro experiment, increased m RNA expression levels of FSH-β, IFNGR1, and IFNGR2 were observed in the treatment group after stimulation with100 U/m L IFN-γ for 24 h compared to those in the control group(P < 0.05).Conclusions: IFN-γ inhibited the phagocytosis of monocytes and macrophages; up-regulated the m RNA expression levels of the FSH-β, IFNGR1, and IFNGR2; enhanced the secretion of FSH; and improved the laying rate. IFN-γ might be an important regulator in the trade-off between the immune effect and production performance in dwarf chickens.
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.
