EXPRESSION OF ACTIN IN THE CENTRAL-NERVOUS-SYSTEM IS SWITCHED OFF DURING DIAPAUSE IN THE GYPSY-MOTH, LYMANTRIA-DISPAR

Diapause-regulated proteins were identified in the CNS of pharate Ist instar larvae of the gypsy moth, Lymantria dispar. Expression of two p roteins (130 kDa and 45 kDa) declined at the time of diapause initiati on and remained low during diapause. At diapause termination, followin g exposure to 5 degrees C for at least 60 days, the 45-kDa protein was again highly expressed. Treatment of young pharate larvae with KK-42 averted diapause, and in such larvae, continued synthesis of the 45 kD a protein in the CNS was observed. These results suggest that expressi on of the 45-kDa protein is strongly down-regulated in the central ner vous system (CNS) during diapause. Partial amino acid sequence determi nation suggested that the 45-kDa protein is actin, and this was confir med using anti-actin antibodies. RT-PCR using primers designed from th e sequence of the gypsy moth mid,out actin mRNA indicated that appeara nce of actin mRNA in the CNS followed the same pattern as that of the 45-kDa protein. The results indicate that diapause controls actin gene expression in the gypsy moth CNS and regulation is at the transcripti onal level. (C) 1998 Elsevier Science Ltd. All rights reserved.