Provided herein, inter alia, are non-human animals comprising nucleic acid sequences encoding a C3 protein that comprises a human sequence as well as transgenic non-human animals comprising a C3 gene that is human in whole or in part as well as methods for using the same to screen for candidate therapeutic molecules to treat complement-related nephropathies. Also provided herein are methods for improving kidney function in an individual diagnosed with or thought to have a complement-related nephropathy.