Molecular Mechanism Of Ptf1a Regulating Early Neural And Pancreatic Development In Xenopus Tropicalis

Pancreatic transcription factor 1a(Ptf1a)encodes a basic helix-loop-helix(b HLH)protein,which is specifically expressed in the vertebrate nervous system and pancreas.Ptf1 a plays important roles in neuron subtype specification,pancreatic progenitor cell fate specification,and the maintenance of adult exocrine pancreas.But little is known about its downstream targets in regulating early neural and pancreatic development.In this study,healthy F2 homozygotes were obtained from a Xenopus tropicalis ptf1a-KI-3×HA-Td-tomato knock-in strain established by CRISPR/Cas9 technology.The red fluorescent signal of Td-tomato reflecting Ptf1 a expression in retina,hindbrain,and pancreas appeared later than the reported m RNA signal.q RT-PCR and Western blot analyses indicated that the expression level of Ptf1 a increased during early embryonic development.Based on the RNA-seq data of stage 34 ptf1 a knockout(KO)whole embryos and published literatures,seven genes related to neurodevelopment were identified from the differentially expressed genes,namely purb,dvl2,nect1,psen2,purne2,slc4a3 and slc6a1.The RNA-seq analyses of the stage 34 and stage 43 ptf1a-KO whole embryos suggest that Ptf1 a might regulate the expression of multiple genes through MAPK,ERb B,GNRH and PPAR signaling pathways.Ch IP-seq(chromatin immunoprecipitation-sequencing)analysis was carried out with dissected pancreata from stage 43 ptf1a-KI-3×HA-Td-tomato tadpoles using the HA-tag antibody.Based on the GO analysis and KEGG analysis of Ch IP-seq data,seven genes related to pancreatic development were identified,namely selenot,hk2,prx,zfp36l2,mapk10,slc30a8 and hes1.In conclusion,this study revealed the Ptf1 a protein expression profile during Xenopus tropicalis early embryogenesis.The established ptf1a-KI-3×HA-Td-tomato strain is useful for studying Ptf1 a function.The preliminary RNA-seq and Ch IP-seq data are helpful for further research on the mechanism by which Ptf1 a regulates the development of central nervous system and pancreas.