Differentiated transcriptional regulation before and after death in Indianmeal moth Plodia interpunctella

Genes differentially regulate transcription processes to maintain biological activities throughout the life of an organism. However, little is known about their fate after organismal death. The Indianmeal moth Plodia interpunctella is a global pest insect that infests stored and manufactured agricultural products. We examined the changes in mRNA levels of nine genes associated with development, stress, and host defense mechanisms before and after death in P. interpunctella adults using quantitative real-time reverse transcription PCR. The results revealed that the transcription rates among genes were not consistent in relation to death. The mRNA levels of hsp25, hsp70, grp78, hsp90, EcR, USP, ProPO, and Tpx gradually increased until the time of death and remained high for at least 5 days. However, βgrp level continuously declined at the time of death. Our results showed that transcriptional activity was maintained after death, which suggests the presence of cellular responses during the post-mortem period.