Receptor for the C-X-C chemokine cxcl12/sdf-1. Transduces a signal by increasing the intracellular level of calcium ions. Signaling with cxcl12/sdf-1 mediates the directional movement of mesodermal cells during gastrulation. May play a role in the migration of embryonic presumptive primordial germ cells (pPGCs). May also be involved in regulating the migration of hematopoietic stem cells into the larval liver. Monomer. Can form dimers (By similarity). Expressed in the cytoplasm of a small number of embryonic pPGCs from stage 24. Expressed in the nucleus of 3 lateral pPGCs. Highly expressed in the embryonic nervous system including forebrain, hindbrain and sensory organs (including eye), and in neural crest cells. Also expressed in the dorsal lateral plate, the first site of definitive hematopoiesis in the embryo. Appears in migrating presumptive primordial germ cells (pPGCs) from stage 24. Expressed in the epidermis at stage 40. In the adult, highly expressed in the spleen with lower levels of expression in the liver and very low levels in kidney, heart, skin and brain. Expression is up-regulated between stages 14-18 (early neurula stages) and remains high until stage 30, decreasing only at stage 45. Sulfation is required for efficient binding of cxcl12/sdf-1alpha and promotes its dimerization. O- and N-glycosylated. Belongs to the G-protein coupled receptor 1 family.