The predominant protein arginine methyltransferase PRMT1 is critical for zebrafish convergence and extension during gastrulation

Protein arginine methyltransferase 1 (PRMT1) is the predominant type I methyltransferase in mammals. Here we use zebrafish (Danio rerio) as the model system to elucidate PRMT1 expression and function during embryogenesis. Zebrafish prmt1 transcripts were detected from the zygote period to the early larva stage. Knock-down prmt1 by antisense morpholino oligo (AMO) resulted in delayed growth, shortened body-length, curled tails and cardiac edema. PRMT1 protein level, type I protein arginine methyltransferase activity, specific asymmetric protein arginine methylation as well as histone H4 R3 methylation decreased in the AMO-injected morphants. The morphants showed defective convergence and extension (C/E) and the abnormalities were more severe at the posterior than the anterior parts. Cell migration defects suggested by the phenotypes were not only observed in the morphant embryos but also in a cellular prmt1 siRNA knock-down model. Rescue of the phenotypes by co-injection of wildtype but not catalytic defective prmt1 mRNA confirmed the specificity of the AMO and the requirement of the methyltransferase activity in early development. This study provides the direct link of protein arginine methylation catalyzed by PRMT1 with early development.