Investigating The Evolutionary Mechanism Underlying Gene Regulatory Network Of Neural Crest Using C.elegans As A Model

The origin of vertebrates was accompanied by the advent of a novel cell type: the neural crest.During gastrulation,the neural crest derived from the neural plate border,which is the boundary between neural plate and non-neural ectoderm.The neural crest cells are multipotent and migratory.These cells contribute to a wide variety of derivatives including craniofacial cartilage,bone,melanocytes,neurons and glia cells.The neural crest have improved the adaption to the environment of vertebrate,contributing to the shift from filter feeding lifestyle of most invertebrates to the active predatory one.To investigate the evolutionary origin of neural crest,the mechanisms underlying neural crest formation and the gene regulatory network responsible for neural crest development were analysized.Caenorhabditis elegans(C.elegans)was used as a model to the study of neural crest evolution for a variety of genetic tools and the similarity between the neuroblast cells of C.elegans and neural plate border cells of vertebrate,which gave rise to neural crest.The Q,V5,P neuroblast cells are located at the lateral border of the central nervous system of C.elegans,and all of them are multipotent.All neuroblast cells differentiated into neurons.Furthermore,Q and P cells can migrate.We generated the expression profile of conserved transcription factors of C.elegans at single-cell resolution and found Msx/vab-15 regulated the migration and differentiation of neuroblast cells.The function of Msx/vab-15 was also validated in fly and ciona.ZNF703/tlp-1,a novel regulator of neuroblast cells has been proved functions synergistically with Msx/vab-15 both in C.elegans and frog.We examined the differentiation gene battery of mechanosensory neurons at C.elegans and fly,and found the differentiation gene battery of vertebrate also existed in C.elegans.The study indicates that the gene regulatory module specifies lateral neural borders is conserved and C.elegans can be used as model for investing neural crest GRN though their distance of evolution.