Zebrafish Minichromosome Maintenance Protein 5 Gene Regulates the Development and Migration of Facial Motor Neurons via Fibroblast Growth Factor Signaling

Minichromosome maintenance protein 5 (MCM5), a member of the microchromosomal maintenance protein family, plays an important role in the initiation and extension of DNA replication. However, its role in neural development in zebrafish remains unclear. Here, we used morpholino (MO) and CRISPR/Cas9 to knock downmcm5 and investigated the developmental features of facial motor neurons (FMNs) in the hindbrain of zebrafish. We found that knockdown ofmcm5 usingmcm5 MO resulted in a small head, small eyes, and a blurred midbrain-hindbrain boundary, while MO injection ofmcm5 led to decrease in FMNs and their migration disorder. However, the mutant ofmcm5 only resulted in the migration defect of FMNs rather than quantity change. We further investigated the underlying mechanism ofmcm5 in the development of hindbrain using in situ hybridization (ISH) andfgfr1a mRNA co-injected withmcm5 MO. Results from ISH showed that the fibroblast growth factor (FGF) signaling pathway was changed when the MCM5 function was lost, with the decrease infgfr1a and the increase infgf8, while that ofpea3 had opposite trend. FMN development defects were rescued byfgfr1a mRNA co-injected withmcm5 MO. Our results demonstrated that FGF signaling pathway is required for FMN development in zebrafish. Specifically,mcm5 regulates FMN development during zebrafish growing.Dev Neurosci
Source: Developmental Neuroscience - Category: Neuroscience Source Type: research