Figure 1.

Members of the lysophospholipid (lp) receptor gene family are expressed by SCs in vivo and in vitro. (a) Northern blots of total RNA from sciatic nerve at various postnatal (P) days and adult (AD) or from cultured neonatal sciatic nerve SCs (SC) were probed for transcripts encoding the five known members of the LP GPCR family (3). Lp_A genes encode LPA receptors, and lp_B genes encode S1P receptors (see refs. 3 and 10 for nomenclature; alternate gene names are given in parentheses). The structures of the two ligands are shown at right (R represents the acyl chain, which can vary in length). The LPA receptor lp_A1/vzg-1 is expressed at high levels by SCs both in vivo and in vitro. Expression of a related LPA receptor gene (lp_A2/edg-4) (5) is undetectable. Of the three genes encoding S1P receptors (3, 6–8, 10), only lp_B3 is expressed prominently by SCs in vitro, although both lp_B1 and lp_B3 are expressed in vivo. A cyclophilin probing is shown as a loading and transfer control. Markers represent 4.4 (upper bands) and 2.4 (lower bands) kb. (b) In situ hybridization (ISH) by using an antisense lp_A1/vzg-1 riboprobe demonstrates that all SCs in vitro express this receptor gene. A sense probe produced no hybridization signal. Nuclear 4′,6-diamidino-2-phenylindole (DAPI) staining of the same microscope field is shown to the right of each ISH panel. (Bars = 80 μm.)