CLONING OF A STRUCTURAL AND FUNCTIONAL HOMOLOG OF THE CIRCADIAN CLOCKGENE PERIOD FROM THE GIANT SILKMOTH ANTHERAEA-PERNYI

The period (per) gene of Drosophila plays an important role in circadi an clock function. Interestingly, homologs of per have not been cloned outside of dipteran species. Using a PCR strategy, we now report the cloning of the cDNA of a per homolog from the silkmoth Antheraea perny i. The cDNA encodes a protein of 849 amino acids, which shows highest identity (39%) with the per protein of Drosophila virilis. Stretches o f high identity between moth and fly proteins are in the amino terminu s, the PAS region, and the region surrounding the site of the per(s) m utation in Drosophila. Moth per homolog mRNA levels exhibit a prominen t circadian variation in adult heads, and per protein antibodies show a pronounced variation of per antigen staining in photoreceptor nuclei . With sequence information derived from moth and flies, per-like cDNA fragments were readily cloned by PCR from other moth species and a th ird insect order.