Differential Expression of Middle Silk Gland Proteins Caused by Cold Stress in Philosamia ricini

This study reports differentially expressed proteins in the middle silkglands of normal and cold stress treated 5th instar Philosamia ricini larvae by using high resolution two-dimensional polyacrylamide gel electrophoresis. About 300 protein spots were resolved in both type of the larvae. Most of the proteins were shown to be distributed in the area from 20 to 70 kDa ranging between pH 4 and 8. Six proteins showed considerably decreased expression in cold stress treated samples. Three proteins displayed increased level of expression after cold stress treatment, while two other proteins were expressed exclusively in cold stress treated silkgland tissues.