Ligands for EPH-related tyrosine kinase receptors are developmentally regulated in the CNS

Elk is a member of the eph family of receptor-like tyrosine kinases. Although its function is unknown, elk is postulated to play a role in nervous system development. Using Northern analysis, we examined the developmental regulation of RNAs encoding elk, and several ligands for the eph family of RTKs, the LERKs. Expression of elk, LERK-1, and LERK-2 RNAs is high in all regions examined in the embryonic and postnatal rat brain and decreases to low levels with age. One exception is the adult olfactory bulb which continues to express a moderate level of LERK-2. In contrast, moderate LERK-4 expression was limited to the developing hippocampus and cerebral cortex. These data indicate that elk and some of the LERKs may play a role in nervous system development, maintenance, and/or regeneration.