Identification of two novel diurnal genes by screening of a rat brain cDNAlibrary

WHILE the hypothalamus is fundamental for sleep and circadian regulation, t he molecular mechanisms involved are poorly understood. We have used a diff erential gene expression technique to identify hypothalamic genes which hav e altered expression in rat sleep periods. Complex cDNA probes from rat hyp othalami removed at Zeitgeber times 4 and 15 were hybridised to rat brain c DNA library girds. From 30 differentially expressed clones, six were furthe r analysed and two were confirmed to exhibit increased expression at Zeitge ber time 4. A Northern blot hybridization of brain, heart, kidney, lung, te stis and skin mRNA showed that both clones were brain specific. Therefore, we have identified two novel brain specific diurnally expressed hypothalami c genes. Both genes may have roles in sleep or circadian regulation. NeuroR eport 9: 3935-3941 (C) 1998 Lippincott Williams & Wilkins.