Enables histone methyltransferase activity (H4-R3 specific) and protein-arginine omega-N symmetric methyltransferase activity. Involved in DNA methylation involved in gamete generation; histone arginine methylation; and regulation of gene expression by genetic imprinting. Predicted to be located in cytosol; fibrillar center; and nucleoplasm. Is expressed in several structures, including brain and retina nuclear layer. Orthologous to human PRMT7 (protein arginine methyltransferase 7). [provided by Alliance of Genome Resources, Apr 2022]