To investigate the effects of plasma exosomes from sheep on animal hair growth,exo-somes were extracted from two sheep breeds with significant differences in wool fineness(Xinji Fine-wool sheep and Small-tailed Han sheep)using biphasic precipitation.The exosomes were characterized by transmission electron microscopy(TEM)and nanoparticle tracking analysis(NTA).A murine alopecia areata model was established,followed by subcutaneous injection of ex-osomes for 7 consecutive days.Dorsal skin samples were collected on day 10 post-injection for his-tological analysis via hematoxylin-eosin(HE)staining.miRNA and mRNA libraries were constructed through qPCR,while TargetScan and g:Profiler were employed for target gene predic-tion and KEGG enrichment analysis,respectively.Protein-protein interaction(PPI)networks were analyzed using STRING to identify key miRNA-mRNA targets,which were preliminarily validated by qPCR.Results demonstrated that on day 5 post-injection,the Small-tailed Han sheep plasma ex-osome group(SPE)exhibited more melanin deposition spots compared to the Xinji Fine-wool sheep plasma exosome group(XPE),with XPE showing greater melanin spots than the control group(NC).Histological analysis revealed that XPE group displayed significantly fewer hair folli-cles compared to SPE and NC groups(P＜0.01),while SPE group exhibited significantly larger hair follicle diameters than both XPE and NC groups(P＜0.01).Bioinformatics analysis predicted 357,711,477,346,and 3 178 target genes for miR-150,miR-133b,miR-31-5p,miR-433-3p,and miR-218,respectively,with 508 genes being co-regulated by two or more miRNAs.PPI analysis i-dentified 217 genes involved in positive regulation of cellular processes,109 in developmental regu-lation,133 in cellular development,132 in cell differentiation,and 69 in regulation of cell differenti-ation.Target genes were found to regulate hair follicle growth through Wnt signaling via Frizzled receptor binding and downstream pathways involving calmodulin(CaM)and cyclic-AMP response binding protein(CREB).qPCR validation showed significantly higher relative expression levels of miR-218,miR-150,miR-31-5p,miR-133b,and miR-433-3p in SPE and XPE groups compared to NC,with SPE exhibiting greater expression than XPE.Additionally,significant differences in FZD4,WNT4,CREB1,and FZD3 expression were observed between treatment groups and NC.These findings demonstrate that plasma exosomes from Xinji Fine-wool and Small-tailed Han sheep modulate hair growth by altering miRNA-mRNA expression profiles in skin tissues.

To investigate the pathogenicity of Sheep-origin Proteus mirabilis and the immunity effect of its inactivated vaccine.In this study,autopsy were performed on sick and dead sheep with severe diarrhea,collected liver,spleen and other diseased organs.And identified the isolated strains by morphology,Gram staining microscopy,biochemical test,molecular biology and 16S rRNA se-quencing;Drug resistance and pathogenicity were studied by drug sensitivity test,pathogenicity test in mouse and pathological histological observation;The isolated strains were inactivated by formaldehyde and mixed with alum adjuvant containing aluminum hydroxide to prepare the inacti-vated vaccine;mice were immunized after safety testing to test antibodies,cytokines and evaluate the immunological effects.Results showed that the isolate was Gram-negative short bacillus with blunt rounded ends after purification staining.Combined with biochemical tests,PCR amplified fragments and 16S rRNA sequencing results showed that the strain was Proteus mirabilis;The re-sults of drug sensitivity test showed that the isolate was highly sensitive to four antibiotics,including amikacin and piperacillin(S),the rest of the strain was moderately or poorly sensitive,or even resistant;The isolate was highly sensitive to the four antibiotics,such as amikacin and pip-eracillin(S).The lethal concentration of the isolated strain was 1.6 × 105 CFU/mL and it could cause different degrees of congestion and bruising and inflammatory cell infiltration in the liver,spleen and other major organs;The formaldehyde inactivated vaccine did not cause adverse reac-tions in mice,and the serum levels of antibodies to IgG,IgG1 and IgG2a,and the levels of antibod-ies to IL-4 and IFN-γ were higher than that of the PBS group,and the vaccine immunoprotection rate was 90％in the attacking bacterial test.In the present experiment,Proteus mirabilis was suc-cessfully isolated from the organs of sick and dead sheep.The inactivated vaccine prepared by form-aldehyde inactivation method can mediate humoral immunity to play a preventive role against the infection of S.chimaera,which can provide a new method for the prevention of bacterial diseases in sheep breeding.

To investigate the pathogenicity of Sheep-origin Proteus mirabilis and the immunity effect of its inactivated vaccine.In this study,autopsy were performed on sick and dead sheep with severe diarrhea,collected liver,spleen and other diseased organs.And identified the isolated strains by morphology,Gram staining microscopy,biochemical test,molecular biology and 16S rRNA se-quencing;Drug resistance and pathogenicity were studied by drug sensitivity test,pathogenicity test in mouse and pathological histological observation;The isolated strains were inactivated by formaldehyde and mixed with alum adjuvant containing aluminum hydroxide to prepare the inacti-vated vaccine;mice were immunized after safety testing to test antibodies,cytokines and evaluate the immunological effects.Results showed that the isolate was Gram-negative short bacillus with blunt rounded ends after purification staining.Combined with biochemical tests,PCR amplified fragments and 16S rRNA sequencing results showed that the strain was Proteus mirabilis;The re-sults of drug sensitivity test showed that the isolate was highly sensitive to four antibiotics,including amikacin and piperacillin(S),the rest of the strain was moderately or poorly sensitive,or even resistant;The isolate was highly sensitive to the four antibiotics,such as amikacin and pip-eracillin(S).The lethal concentration of the isolated strain was 1.6 × 105 CFU/mL and it could cause different degrees of congestion and bruising and inflammatory cell infiltration in the liver,spleen and other major organs;The formaldehyde inactivated vaccine did not cause adverse reac-tions in mice,and the serum levels of antibodies to IgG,IgG1 and IgG2a,and the levels of antibod-ies to IL-4 and IFN-γ were higher than that of the PBS group,and the vaccine immunoprotection rate was 90％in the attacking bacterial test.In the present experiment,Proteus mirabilis was suc-cessfully isolated from the organs of sick and dead sheep.The inactivated vaccine prepared by form-aldehyde inactivation method can mediate humoral immunity to play a preventive role against the infection of S.chimaera,which can provide a new method for the prevention of bacterial diseases in sheep breeding.

To investigate the effects of plasma exosomes from sheep on animal hair growth,exo-somes were extracted from two sheep breeds with significant differences in wool fineness(Xinji Fine-wool sheep and Small-tailed Han sheep)using biphasic precipitation.The exosomes were characterized by transmission electron microscopy(TEM)and nanoparticle tracking analysis(NTA).A murine alopecia areata model was established,followed by subcutaneous injection of ex-osomes for 7 consecutive days.Dorsal skin samples were collected on day 10 post-injection for his-tological analysis via hematoxylin-eosin(HE)staining.miRNA and mRNA libraries were constructed through qPCR,while TargetScan and g:Profiler were employed for target gene predic-tion and KEGG enrichment analysis,respectively.Protein-protein interaction(PPI)networks were analyzed using STRING to identify key miRNA-mRNA targets,which were preliminarily validated by qPCR.Results demonstrated that on day 5 post-injection,the Small-tailed Han sheep plasma ex-osome group(SPE)exhibited more melanin deposition spots compared to the Xinji Fine-wool sheep plasma exosome group(XPE),with XPE showing greater melanin spots than the control group(NC).Histological analysis revealed that XPE group displayed significantly fewer hair folli-cles compared to SPE and NC groups(P＜0.01),while SPE group exhibited significantly larger hair follicle diameters than both XPE and NC groups(P＜0.01).Bioinformatics analysis predicted 357,711,477,346,and 3 178 target genes for miR-150,miR-133b,miR-31-5p,miR-433-3p,and miR-218,respectively,with 508 genes being co-regulated by two or more miRNAs.PPI analysis i-dentified 217 genes involved in positive regulation of cellular processes,109 in developmental regu-lation,133 in cellular development,132 in cell differentiation,and 69 in regulation of cell differenti-ation.Target genes were found to regulate hair follicle growth through Wnt signaling via Frizzled receptor binding and downstream pathways involving calmodulin(CaM)and cyclic-AMP response binding protein(CREB).qPCR validation showed significantly higher relative expression levels of miR-218,miR-150,miR-31-5p,miR-133b,and miR-433-3p in SPE and XPE groups compared to NC,with SPE exhibiting greater expression than XPE.Additionally,significant differences in FZD4,WNT4,CREB1,and FZD3 expression were observed between treatment groups and NC.These findings demonstrate that plasma exosomes from Xinji Fine-wool and Small-tailed Han sheep modulate hair growth by altering miRNA-mRNA expression profiles in skin tissues.