Rapid and efficient conversion of common marmoset fibroblasts into mature and functional neurons by overexpression of ASCL1 and microRNA-9/9*-124
The common marmoset (marmoset; Callithrix jacchus) has been attracting much attention especially in the research fields of biomedical science and neuroscience, because of its potential to recapitulate the complex and multidimensional phenotypes of human diseases. Taking these advantages, several transgenic models have been reported so far. However, there remain several issues such as (i) it takes years to generate the late-onset disease models, and (ii) the onset age and severity of phenotypes can vary among individual animals due to their differences in the genetic background. In the present study, we established an efficient and rapid direct neuronal induction method (induced Neuron; iN) from embryonic and adult marmoset fibroblasts. This iN method is a minimally invasive approach to investigate cellular-level phenotypes in the marmoset brain. We overexpressed microRNA-9/9*-124 and a transcription factor ASCL1 in fibroblasts with a small molecule cocktail that ameliorates neuronal induction. The resultant iN cells from both embryonic and adult marmoset fibroblasts showed standard neuronal characteristic within 2 weeks, including neuronal specific gene expression and neuronal membrane spontaneous firing activity. Thus, this novel neuronal induction method may offer a new tool for investigating neurological phenotypes in vitro without collecting living brain tissue in non-human primate neurological disease models. Overall design: RNA seq of marmoset fibroblasts and iNs