The gene regulatory basis of genetic compensation during neural crest induction

by Christopher M. Dooley, Neha Wali, Ian M. Sealy, Richard J. White, Derek L. Stemple, John E. Collins, Elisabeth M. Busch-Nentwich

The neural crest (NC) is a vertebrate-specific cell type that contributes to a wide range of different tissues across all three germ layers. The gene regulatory network (GRN) responsible for the formation of neural crest is conserved across vertebrates. Central to the induction of the NC GRN areAP-2 andSoxE transcription factors. NC induction robustness is ensured through the ability of some of these transcription factors to compensate loss of function of gene family members. However the gene regulatory events underlying compensation are poorly understood. We have used gene knockout and RNA sequencing strategies to dissect NC induction and compensation in zebrafish. We genetically ablate the NC using double mutants oftfap2a;tfap2c or remove specific subsets of the NC withsox10 andmitfa knockouts and characterise genome-wide gene expression levels across multiple time points. We find that compensation through a single wild-type allele oftfap2c is capable of maintaining early NC induction and differentiation in the absence oftfap2a function, but many target genes have abnormal expression levels and therefore show sensitivity to the reducedtfap2 dosage. This separation of morphological and molecular phenotypes identifies a core set of genes required for early NC development. We also identify the 15 somites stage as the peak of the molecular phenoty...

Source: PLoS Genetics - June 13, 2019 Category: Genetics & Stem Cells Authors: Christopher M. Dooley Source Type: research