Predicted to enable G protein-coupled receptor binding activity and heparin binding activity. Predicted to be involved in positive regulation of canonical Wnt signaling pathway; positive regulation of protein phosphorylation; and regulation of receptor internalization. Predicted to act upstream of or within several processes, including male meiotic nuclear division; positive regulation of non-canonical Wnt signaling pathway; and regulation of male germ cell proliferation. Predicted to be located in extracellular space and nucleus. Orthologous to human RSPO1 (R-spondin 1). [provided by Alliance of Genome Resources, Apr 2022]