The Japanese lamprey (Lethenteron camtschaticum) expresses functional lysophosphatidic acid receptors.

Lysophosphatidic acid (LPA) signaling plays diverse roles in the development of various vertebrates such as mammals and fish. The lamprey is a fish that retains ancestral features of vertebrates, but information regarding lamprey LPA receptor genes is limited. Here, using information from the lamprey genome database, we cloned two LPA receptor genes, Lpar1 and Lpar5, from the Japanese lamprey (Lethenteron camtschaticum). Lamprey Lpar1 had a high amino acid identity to mouse and medaka fish Lpar1, whereas Lpar5 amino acid sequences were more diverse between species. Our functional analyses using a heterologous expression system demonstrated that Lpar1 and Lpar5 responded to LPA treatment with G-associated cellular responses, which are indicative of cytoskeletal actions. The existence of functional LPA receptors in the Japanese lamprey suggests that LPA receptor-dependent signals contribute to lamprey growth and development.