Whether endogenous neurogenesis occurs in the adult cortex remains controversial.An increasing number of reports suggest that doublecortin(DCX)-positive neurogenesis persists in the adult primate cortex,attracting eno...Whether endogenous neurogenesis occurs in the adult cortex remains controversial.An increasing number of reports suggest that doublecortin(DCX)-positive neurogenesis persists in the adult primate cortex,attracting enormous attention worldwide.In this study,different DCX antibodies were used together with NeuN antibodies in immunohistochemistry and western blot assays using adjacent cortical sections from adult monkeys.Antibody adsorption,antigen binding,primary antibody omission and antibody-free experiments were used to assess specificity of the signals.We found either strong fluorescent signals,medium-weak intensity signals in some cells,weak signals in a few perikarya or near complete lack of labeling in adjacent cortical sections incubated with the various DCX antibodies.The putative DCX-positive cells in the cortex were also positive for NeuN,a specific marker of mature neurons.However,further experiments showed that most of these signals were either the result of antibody cross reactivity,the non-specificity of secondary antibodies or tissue autofluorescence.No confirmed DCX-positive cells were detected in the adult macaque cortex by immunofluorescence.Our findings show that DCX-positive neurogenesis does not occur in the cerebral cortex of adult primates,and that false-positive signals(artefacts)are caused by antibody cross reactivity and autofluorescence.The experimental protocols were approved by the Institutional Animal Care and Use Committee of the Institute of Neuroscience,Beijing,China(approval No.IACUC-AMMS-2014-501).展开更多
A nation-wide case surveillance was conducted in China since 1995 for the objective of identifying acute flaccid paralysis(AFP)in children so that potential wild polioviruses and vaccine-derived poliovirus(VDPV)could ...A nation-wide case surveillance was conducted in China since 1995 for the objective of identifying acute flaccid paralysis(AFP)in children so that potential wild polioviruses and vaccine-derived poliovirus(VDPV)could be identified on time.Two outbreaks associated with type I circulating VDPVs,eight native independent type I ambiguous VDPVs(aVDPV),and one imported aVDPV were identified during the AFP case surveillance in China from 1995 to 2019.The VP1 coding region of the Chinese type I VDPVs differed from the polio vaccine strain by 1.00%–3.75%(9–34 substitutions in 906 nucleotides).Most of the Chinese type I VDPV strains shared 4 amino acid substitutions in the neutralizing antigenic(NAg)sites:3 located at the BC loop,which formed the NAg site 1,and another at NAg site 3a.All of the Chinese type I VDPVs identified during the AFP case surveillance were young VDPVs,which indicated a limited viral replication resulted from the administration of the initiating oral polio vaccine(OPV)dose.VDPVs can emerge and spread in isolated communities with immunity gaps and the circulation ceases following a mass immunization with OPV.As such,high-quality surveillance permitted very early detection and response and it played a key role in stalling the widespread circulation of the emergent cVDPV strains in China.展开更多
基金supported by the National Natural Science Foundation of China(Key Program),No.30430310(to SJL)the State Key Laboratories Development Program of China,No.SKLP-K201401(to SJL)
文摘Whether endogenous neurogenesis occurs in the adult cortex remains controversial.An increasing number of reports suggest that doublecortin(DCX)-positive neurogenesis persists in the adult primate cortex,attracting enormous attention worldwide.In this study,different DCX antibodies were used together with NeuN antibodies in immunohistochemistry and western blot assays using adjacent cortical sections from adult monkeys.Antibody adsorption,antigen binding,primary antibody omission and antibody-free experiments were used to assess specificity of the signals.We found either strong fluorescent signals,medium-weak intensity signals in some cells,weak signals in a few perikarya or near complete lack of labeling in adjacent cortical sections incubated with the various DCX antibodies.The putative DCX-positive cells in the cortex were also positive for NeuN,a specific marker of mature neurons.However,further experiments showed that most of these signals were either the result of antibody cross reactivity,the non-specificity of secondary antibodies or tissue autofluorescence.No confirmed DCX-positive cells were detected in the adult macaque cortex by immunofluorescence.Our findings show that DCX-positive neurogenesis does not occur in the cerebral cortex of adult primates,and that false-positive signals(artefacts)are caused by antibody cross reactivity and autofluorescence.The experimental protocols were approved by the Institutional Animal Care and Use Committee of the Institute of Neuroscience,Beijing,China(approval No.IACUC-AMMS-2014-501).
基金This study was supported by the National Science and Technology Major Project of China(Project Nos.2018ZX10711001,2017ZX10104001,and 2018ZX10713002).
文摘A nation-wide case surveillance was conducted in China since 1995 for the objective of identifying acute flaccid paralysis(AFP)in children so that potential wild polioviruses and vaccine-derived poliovirus(VDPV)could be identified on time.Two outbreaks associated with type I circulating VDPVs,eight native independent type I ambiguous VDPVs(aVDPV),and one imported aVDPV were identified during the AFP case surveillance in China from 1995 to 2019.The VP1 coding region of the Chinese type I VDPVs differed from the polio vaccine strain by 1.00%–3.75%(9–34 substitutions in 906 nucleotides).Most of the Chinese type I VDPV strains shared 4 amino acid substitutions in the neutralizing antigenic(NAg)sites:3 located at the BC loop,which formed the NAg site 1,and another at NAg site 3a.All of the Chinese type I VDPVs identified during the AFP case surveillance were young VDPVs,which indicated a limited viral replication resulted from the administration of the initiating oral polio vaccine(OPV)dose.VDPVs can emerge and spread in isolated communities with immunity gaps and the circulation ceases following a mass immunization with OPV.As such,high-quality surveillance permitted very early detection and response and it played a key role in stalling the widespread circulation of the emergent cVDPV strains in China.
