Objective:To characterize Pasteurella isolated from backyard chickens using whole cell protein lysate profiles and random amplified polymorphic DNA(RAPD)techniques to show their genetic relationship because Pasteurcll...Objective:To characterize Pasteurella isolated from backyard chickens using whole cell protein lysate profiles and random amplified polymorphic DNA(RAPD)techniques to show their genetic relationship because Pasteurclla multocida(P.multocida)is an important cause of fatal infections in backyard chickens.Methods:Twenty one P.multocida isolates were recovered previously from clinical cases of fowl cholera belonging to individual owners and phenotypically analysed using biochemical tests and serotyping were used far the genetic characterization.Results:Phylogenetic study based on both methods revealed that the recovered population of P.multocida isolated from backyard chickens differs markedly,constituting a well-separated cluster and appearance of 3 distinguishing lineages with greater discrimination shown by RAPDPCR that resulted in two suclusters in cluster A and three subclusters in cluster B and were related greatly with capsular serogroups for the examined strains.The whole cell protein revealed the presence of dominant protein bands at approximately 41 and 61 kDa in all of the examined isolates that may be a virulent proteins share in the increasing of its pathogenicity.Clear distinctive bands ranged from 123 to 1534 bp.Conclusions:Based on the previous findings,there are three spreading clusters that may indicate the association of a small number of P.multocida variants with the majority of cases suggesting that certain clones of P.multocida are able to colonue the examined backyard chickens.Also,the ease and rapidity of RAPD-PCR support the use of this technique as alternative to the more labour-intensive SDS-PACE system for strain differentiation and epidemiological studies of avian P.multocida.Further application of RAPD technology to the examination of avian cholera outbreaks in commercially available flocks may facilitate more effective management of this disease by providing the potential to investigate correlations of P.multocida genotypes,to identify affiliations between bird types and bacterial genotypes,and to elucidate the role of specific bird species in disease transmission.展开更多
Background:Excessive abdominal fat deposition in commercial broilers presents an obstacle to profitable meat quality,feed utilization,and reproduction.Abdominal fat deposition depends on the proliferation of preadipoc...Background:Excessive abdominal fat deposition in commercial broilers presents an obstacle to profitable meat quality,feed utilization,and reproduction.Abdominal fat deposition depends on the proliferation of preadipocytes and their maturation into adipocytes,which involves a cascade of regulatory molecules.Accumulating evidence has shown that microRNAs(miRNAs)serve as post-transcriptional regulators of adipogenic differentiation in mammals.However,the miRNA-mediated molecular mechanisms underlying abdominal fat deposition in chickens are still poorly understood.This study aimed to investigate the biological functions and regulatory mechanism of miRNAs in chicken abdominal adipogenesis.Results:We established a chicken model of abdominal adipocyte differentiation and analyzed miRNA and mRNA expression in abdominal adipocytes at different stages of differentiation(0,12,48,72,and 120 h).A total of 217 differentially expressed miRNAs(DE-miRNAs)and 3520 differentially expressed genes were identified.Target prediction of DE-miRNAs and functional enrichment analysis revealed that the differentially expressed targets were significantly enriched in lipid metabolism-related signaling pathways,including the PPAR signaling and MAPK signaling pathways.A candidate miRNA,gga-miR-106-5p,exhibited decreased expression during the proliferation and differentiation of abdominal preadipocytes and was downregulated in the abdominal adipose tissues of fat chickens compared to that of lean chickens.gga-miR-106-5p was found to inhibit the proliferation and adipogenic differentiation of chicken abdominal preadipocytes.A dual-luciferase reporter assay suggested that the KLF15 gene,which encodes a transcriptional factor,is a direct target of gga-miR-106-5p.gga-miR-106-5p suppressed the posttranscriptional activity of KLF15,which is an activator of abdominal preadipocyte proliferation and differentiation,as determined with gain-and loss-of-function experiments.Conclusions:gga-miR-106-5p functions as an inhibitor of abdominal adipogenesis by targeting the KLF15 gene in chickens.These findings not only improve our understanding of the specific functions of miRNAs in avian adipogenesis but also provide potential targets for the genetic improvement of excessive abdominal fat deposition in poultry.展开更多
Background:The egg production performance of chickens is affected by many factors,including genetics,nutrition and environmental conditions.These factors all play a role in egg production by affecting the development ...Background:The egg production performance of chickens is affected by many factors,including genetics,nutrition and environmental conditions.These factors all play a role in egg production by affecting the development of follicles.MicroRNAs(miRNAs)are important non-coding RNAs that regulate biological processes by targeting genes or other non-coding RNAs after transcription.In the animal reproduction process,miRNA is known to affect the development and atresia of follicles by regulating apoptosis and autophagy of granulosa cells(GCs).Results:In this study,we identified potential miRNAs in the atretic follicles of broody chickens and unatretic follicles of healthy chickens.We identified gga-miR-30a-5p in 50 differentially expressed miRNAs and found that gga-miR-30a-5p played a regulatory role in the development of chicken follicles.The function of miR-30a-5p was explored through the transfection test of miR-30a-5p inhibitor and miR-30a-5p mimics.In the study,we used qPCR,western blot and flow cytometry to detect granulosa cell apoptosis,autophagy and steroid hormone synthesis.Confocal microscopy and transmission electron microscopy are used for the observation of autophagolysosomes.The levels of estradiol(E2),progesterone(P4),malondialdehyde(MDA)and superoxide dismutase(SOD)were detected by ELISA.The results showed that miR-30a-5p showed a negative effect on autophagy and apoptosis of granulosa cells,and also contributed in steroid hormones and reactive oxygen species(ROS)production.In addition,the results obtained from the biosynthesis and dual luciferase experiments showed that Beclin1 was the target gene of miR-30a-5p.The rescue experiment conducted further confirmed that Beclin1 belongs to the miR-30a-5p regulatory pathway.Conclusions:In summary,after deep miRNA sequencing on healthy and atretic follicles,the results indicated that miR-30a-5p inhibits granulosa cell death by inhibiting Beclin1.展开更多
Bovine Respiratory Disease (BRD) causes a severe form of pneumonia in all age of cattle. This study was designed to investigate the distribution of capsular types, serotypes, and virulence-associated genes of the majo...Bovine Respiratory Disease (BRD) causes a severe form of pneumonia in all age of cattle. This study was designed to investigate the distribution of capsular types, serotypes, and virulence-associated genes of the major bacterial pathogens from BRD outbreak samples in Ethiopia. In this study 166 samples were collected from clinically sick (<i>n</i> = 107) and pneumonic lung tissue (<i>n</i> = 59). Laboratory assay confirmed isolation of <i>M. haemolytica</i> 37 (22.29%), <i>P. multocida</i> 25 (15.06%), <i>B. trehalosi</i> 12 (7.23%), and <i>H. somni</i> 15 (9.04%). PCR assay of <i>P. multocida</i> capsular typing revealed 21 (84.0%) cap A (<i>hyaD-hyaC</i>) and 4 (16.0%) cap D (<i>dcbF</i>) strains. <i>M. haemolytica</i> serotypes belonged to A: 1, A: 2, and A: 6 from 26 (70.27%), 4 (10.81%), and 7 (18.92%) isolates, respectively. <i>P. multocida</i> biotyping showed isolation of A: 1, A: 2, and A: 3 from 3 (14.29%), 2 (9.52%), and 16 (76.19%) isolates, respectively. <i>M. haemolytica</i> harbored more than 60% <i>ssa</i> gene, and 90.91% <i>sodA</i> while <i>FbpA</i>, <i>TbpA</i>, and <i>lktC</i> genes were found in all isolates. Likewise, all <i>P. multocida</i> exhibited <i>toxA</i>, <i>FbpA</i>, <i>TbpA</i>, and <i>pmSLP</i> genes. The current finding showed that <i>M. haemolytica</i> serotype A: 1 is frequently associated with BRD followed by <i>P. multocida</i> biotype A: 3. These two isolates harbored diverse virulence-associated genes and presented the pathogenic potential of the current isolates. Thus, investigation of pathogenic strains of BRD, virulence genes distribution, and molecular epidemiology of the disease from wider areas of the country are essential. Hence, continuous outbreak surveillance and molecular approaches are indispensable in designing efficient prevention strategies.展开更多
基金Supported by Regular goveromental annual fund every Fiscal year from Assiut university(Grant No.9/020/08595/0)
文摘Objective:To characterize Pasteurella isolated from backyard chickens using whole cell protein lysate profiles and random amplified polymorphic DNA(RAPD)techniques to show their genetic relationship because Pasteurclla multocida(P.multocida)is an important cause of fatal infections in backyard chickens.Methods:Twenty one P.multocida isolates were recovered previously from clinical cases of fowl cholera belonging to individual owners and phenotypically analysed using biochemical tests and serotyping were used far the genetic characterization.Results:Phylogenetic study based on both methods revealed that the recovered population of P.multocida isolated from backyard chickens differs markedly,constituting a well-separated cluster and appearance of 3 distinguishing lineages with greater discrimination shown by RAPDPCR that resulted in two suclusters in cluster A and three subclusters in cluster B and were related greatly with capsular serogroups for the examined strains.The whole cell protein revealed the presence of dominant protein bands at approximately 41 and 61 kDa in all of the examined isolates that may be a virulent proteins share in the increasing of its pathogenicity.Clear distinctive bands ranged from 123 to 1534 bp.Conclusions:Based on the previous findings,there are three spreading clusters that may indicate the association of a small number of P.multocida variants with the majority of cases suggesting that certain clones of P.multocida are able to colonue the examined backyard chickens.Also,the ease and rapidity of RAPD-PCR support the use of this technique as alternative to the more labour-intensive SDS-PACE system for strain differentiation and epidemiological studies of avian P.multocida.Further application of RAPD technology to the examination of avian cholera outbreaks in commercially available flocks may facilitate more effective management of this disease by providing the potential to investigate correlations of P.multocida genotypes,to identify affiliations between bird types and bacterial genotypes,and to elucidate the role of specific bird species in disease transmission.
基金supported by the National Key Research and Development Program of China(2021YFD1200803)Sanya Yazhou Bay Science and Technology City Administration(SYND-2022-28)China Agriculture Research System of MOF and MARA(CARS-40).
文摘Background:Excessive abdominal fat deposition in commercial broilers presents an obstacle to profitable meat quality,feed utilization,and reproduction.Abdominal fat deposition depends on the proliferation of preadipocytes and their maturation into adipocytes,which involves a cascade of regulatory molecules.Accumulating evidence has shown that microRNAs(miRNAs)serve as post-transcriptional regulators of adipogenic differentiation in mammals.However,the miRNA-mediated molecular mechanisms underlying abdominal fat deposition in chickens are still poorly understood.This study aimed to investigate the biological functions and regulatory mechanism of miRNAs in chicken abdominal adipogenesis.Results:We established a chicken model of abdominal adipocyte differentiation and analyzed miRNA and mRNA expression in abdominal adipocytes at different stages of differentiation(0,12,48,72,and 120 h).A total of 217 differentially expressed miRNAs(DE-miRNAs)and 3520 differentially expressed genes were identified.Target prediction of DE-miRNAs and functional enrichment analysis revealed that the differentially expressed targets were significantly enriched in lipid metabolism-related signaling pathways,including the PPAR signaling and MAPK signaling pathways.A candidate miRNA,gga-miR-106-5p,exhibited decreased expression during the proliferation and differentiation of abdominal preadipocytes and was downregulated in the abdominal adipose tissues of fat chickens compared to that of lean chickens.gga-miR-106-5p was found to inhibit the proliferation and adipogenic differentiation of chicken abdominal preadipocytes.A dual-luciferase reporter assay suggested that the KLF15 gene,which encodes a transcriptional factor,is a direct target of gga-miR-106-5p.gga-miR-106-5p suppressed the posttranscriptional activity of KLF15,which is an activator of abdominal preadipocyte proliferation and differentiation,as determined with gain-and loss-of-function experiments.Conclusions:gga-miR-106-5p functions as an inhibitor of abdominal adipogenesis by targeting the KLF15 gene in chickens.These findings not only improve our understanding of the specific functions of miRNAs in avian adipogenesis but also provide potential targets for the genetic improvement of excessive abdominal fat deposition in poultry.
基金financially supported by Sichuan Science and Technology Program(2021YFYZ0031,2021YFYZ0007)China Agriculture Research System of MOF and MARA(CARS-40).
文摘Background:The egg production performance of chickens is affected by many factors,including genetics,nutrition and environmental conditions.These factors all play a role in egg production by affecting the development of follicles.MicroRNAs(miRNAs)are important non-coding RNAs that regulate biological processes by targeting genes or other non-coding RNAs after transcription.In the animal reproduction process,miRNA is known to affect the development and atresia of follicles by regulating apoptosis and autophagy of granulosa cells(GCs).Results:In this study,we identified potential miRNAs in the atretic follicles of broody chickens and unatretic follicles of healthy chickens.We identified gga-miR-30a-5p in 50 differentially expressed miRNAs and found that gga-miR-30a-5p played a regulatory role in the development of chicken follicles.The function of miR-30a-5p was explored through the transfection test of miR-30a-5p inhibitor and miR-30a-5p mimics.In the study,we used qPCR,western blot and flow cytometry to detect granulosa cell apoptosis,autophagy and steroid hormone synthesis.Confocal microscopy and transmission electron microscopy are used for the observation of autophagolysosomes.The levels of estradiol(E2),progesterone(P4),malondialdehyde(MDA)and superoxide dismutase(SOD)were detected by ELISA.The results showed that miR-30a-5p showed a negative effect on autophagy and apoptosis of granulosa cells,and also contributed in steroid hormones and reactive oxygen species(ROS)production.In addition,the results obtained from the biosynthesis and dual luciferase experiments showed that Beclin1 was the target gene of miR-30a-5p.The rescue experiment conducted further confirmed that Beclin1 belongs to the miR-30a-5p regulatory pathway.Conclusions:In summary,after deep miRNA sequencing on healthy and atretic follicles,the results indicated that miR-30a-5p inhibits granulosa cell death by inhibiting Beclin1.
文摘Bovine Respiratory Disease (BRD) causes a severe form of pneumonia in all age of cattle. This study was designed to investigate the distribution of capsular types, serotypes, and virulence-associated genes of the major bacterial pathogens from BRD outbreak samples in Ethiopia. In this study 166 samples were collected from clinically sick (<i>n</i> = 107) and pneumonic lung tissue (<i>n</i> = 59). Laboratory assay confirmed isolation of <i>M. haemolytica</i> 37 (22.29%), <i>P. multocida</i> 25 (15.06%), <i>B. trehalosi</i> 12 (7.23%), and <i>H. somni</i> 15 (9.04%). PCR assay of <i>P. multocida</i> capsular typing revealed 21 (84.0%) cap A (<i>hyaD-hyaC</i>) and 4 (16.0%) cap D (<i>dcbF</i>) strains. <i>M. haemolytica</i> serotypes belonged to A: 1, A: 2, and A: 6 from 26 (70.27%), 4 (10.81%), and 7 (18.92%) isolates, respectively. <i>P. multocida</i> biotyping showed isolation of A: 1, A: 2, and A: 3 from 3 (14.29%), 2 (9.52%), and 16 (76.19%) isolates, respectively. <i>M. haemolytica</i> harbored more than 60% <i>ssa</i> gene, and 90.91% <i>sodA</i> while <i>FbpA</i>, <i>TbpA</i>, and <i>lktC</i> genes were found in all isolates. Likewise, all <i>P. multocida</i> exhibited <i>toxA</i>, <i>FbpA</i>, <i>TbpA</i>, and <i>pmSLP</i> genes. The current finding showed that <i>M. haemolytica</i> serotype A: 1 is frequently associated with BRD followed by <i>P. multocida</i> biotype A: 3. These two isolates harbored diverse virulence-associated genes and presented the pathogenic potential of the current isolates. Thus, investigation of pathogenic strains of BRD, virulence genes distribution, and molecular epidemiology of the disease from wider areas of the country are essential. Hence, continuous outbreak surveillance and molecular approaches are indispensable in designing efficient prevention strategies.
