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 mechanism involved are poorly understood. We have used a diffe rential gene expression technique to identify hypothalamic genes which have altered expression in rat sleep periods. Complex cDNA probes from rat hypo thalami removed at Zeitgeber times 4 and 15 were hybridised to rat brain cD NA library girds. From 30 differentially expressed clones, six were further analysed and two were confirmed to exhibit increased expression at Zeitgeb er time 4. A Northern blot hybridization of brain, heart, kidney, lung, tes tis and skin mRNA showed that both clones were brain specific. Therefore, w e have identified two novel brain specific diurnally expressed hypothalamic genes. Both genes may have roles in sleep or circadian regulation. NeuroRe port 10:1155-1161 (C) 1999 Lippincott Williams & Wilkins.