Gene expression in post mortem dermal tissue

Abstract

The persistence and detection of gene transcripts in post mortem tissues has significance for forensic science and medicine, since there is the potential to provide information about the cause of, or circumstances surrounding, death and the post mortem interval. Previous studies in this area have focused on enzyme activities and the presence of gene transcripts in neural tissues (Palego et al., 1993; Johnson ci aL, 1986). In the study presented in this thesis, the biological material selected was dermal tissue from pigs, since the skin offers a number of advantages for study in a forensic context, such as ease of harvesting and a slower rate of degradation than most other soft body tissues.
Initial chapters describe the development of methodologies for the extraction of RNA from dermal tissue and the detection and quantification of gene transcripts. The genes selected as indicators of gene expression were members of the heat shock gene family, since these genes are highly conserved and easily induced in cells. Subsequent chapters present evidence, not only for the persistence and detection of gene transcripts in post mortem tissue, but also for the inducible de novo expression of heat shock genes in post mortem (PM) tissue. A mild heat shock, applied in the post mortem period to porcine
tissue, elicits the expression of certain genes of the heat shock gene family. These results demonstrate that heat shock genes are highly inducible in the early post mortem period, and that these cells retain the ability to respond to an environmental stimulus by transcribing specific genes.