Involved in several processes, including complement-mediated synapse pruning; microglial cell activation; and nervous system development. Acts upstream of or within complement activation, classical pathway. Located in postsynapse. Is expressed in brain; foot; genitourinary system; and pancreas. Used to study epilepsy and systemic lupus erythematosus. Human ortholog(s) of this gene implicated in glomerulonephritis. Orthologous to human C1QA (complement C1q A chain). [provided by Alliance of Genome Resources, Apr 2022]