STRESS PROTEINS ELICITED BY COLD SHOCK IN THE BITING MIDGE, CULICOIDES-VARIIPENNIS SONORENSIS WIRTH AND JONES

In vivo protein expression in the abdominal viscera of C. v. sonorensi s was examined from adult flies that were cold shocked for various len gths of time at 0, -10, or -15 degrees C and labelled at 25 degrees C with S-35-methionine at 0, 2, 4 and 6 hr during the recovery period. I n vitro labelling showed that seven unique proteins (23, 40, 43, 48, 6 0, 70 and 92 kDa) were produced in C. v. sonorensis exposed to low tem peratures in vivo. In general, the rate of expression and quality of s tress proteins were directly proportional to both the severity and dur ation of the cold shock. A polyclonal antibody to the moth hsp 60/63 c rossreacted with antigen from the viscera of the 60 kDa protein that w as expressed during recovery from cold shock. This crossreaction with C. v. sonorensis suggests that the 60 kDa protein expressed during rec overy from cold shock in the midge is immunologically related to the m oth heat shock protein (hsp). Weather records from central Wyoming sug gest that if the stress proteins produced by C. v. sonorensis enhance survival of the earliest, normally lethal temperatures (e.g., -5 degre es C), populations of these insects can persist for an additional 20-3 0 d in an average year and thus extend the time they can transmit blue tongue virus.