A Comparative Study Of The Expression Characteristics Of D6-Cre, Emx1-Cre, HGFAP-Cre, Three Tools Related To Cerebral Cortex Development

The cerebral cortex which is an important part of the central nervous system in mammals is highly specialized and organized.The generation process of the whole cerebral cortex has temporal and spatial specificity.Neurons in each layer of the cerebral cortex can project to different areas and perform different functions to maintain the normal function of the nervous system.Abnormalities in the type and distribution of these neurons can result in many clinical diseases,including autism,schizophrenia,and epilepsy.Therefore,it is of great significance to study the precise and orderly generation and localization of neurons during the development.In the laboratory,previous work,in situ hybridization technology was used to find that D6-cre and hGFAP-cre mediated Dicer conditional knockout mice showed microRNA deletion caused by Dicer knockout,but there also showed some difference between these two conditional knockout mice.In order to explore the reasons for the different phenotype,we compared the expression characteristics of D6-cre,Emxl-cre and hGFAP-cre,which were widely used in the study of cerebral cortex.In this study,it was found that the initial expression time of Cre recombinase in cerebral cortex of Emxl-cre,D6-cre and hGFAP-cre mouse was embryonic 9.5 days(E9.5),after E10.5 and E12.5,respectively.As time went by,the expression of D6-cre recombinase was always limited to the telencephalon,while the expression range of Emxl-cre and hGFAP-cre kept expanding.At the same time,the phenomenon of abnormal radial migration of neurons occurred in different Dicer conditioned-knockout mice.Previous work suggested that miR-129 might be related to the migration of neurons in the cerebral cortex.In this study,after overexpression of miR-129 through mouse in utero electrocution,it was found that the neuronal migration in cerebral cortex was inhibited.After overexpression of Fmrl,the migration of neurons in cerebral cortex could be promoted without affecting the fate of neurons.Simultaneous overexpression of mir-129 and Fmrl in mice brains partially alleviated the inhibition of neuronal migration induced by overexpression of miR-129.To sum up,we have found that D6-cre,Emxl-cre and hGFAP-cre have different expression patterns,which is slightly different from the literature.In terms of the regulation of cortical neuron migration,it has been found that miR-129 can target the Fmrl gene,thus regulating the process of cortical neuron migration.