Study On The Development Of Parasarcophaga Similis And The Differential Gene Expression Of Pupa Of Chrysomya Megacephala To Estimate Postmortem Interval

The PMI(Postmortem Interval) is the interval from the time the death happens to the time the corpse be found in forensic medicine. In most of the time, it indicates the time the crime happened. It cou Ld be used determine the assurance and elimination of the suspect in order to plot the investigation range. At present, many research on PMI have been carried out in the world.Larvae and pupae are the most easily observed targets of insects in case investigation, especially for corruption in the latter part of the body. Currently, in terms of age inferred insect, a widely used traditional indicators include: the duration of the development of insect, the size of larva and intra-puparial development. In recent years, gene expression has become the latest method to infer the age of insects, and has been verified.This study includes two parts.The first part is the growth and development Law of Parasarcophaga similis. Establish flies through laboratory popu Lations of developmental duration nine Temperature wild flax flies under observation, and the larvae and pupae sampling and observation. Wild flax fly wide temperature range from 15 ° C-35 ° C life cycle can be completed. As the temperature increases, developmental duration decreases gradually reduced from 1029 h at 15 °C for 237 h at 35 ° C under development rate gradually increases; by ADH model to calcu Late wild flax fly developmental threshold temperature is 9.6 °C, the effective growth accumu Lated to 5675.32 ° Ch; drawn Isomorphen diagram model, it can visually isolated from the chart duration of each developmental events at different temperatures; the establishment of a curve model and larvae equation model, and draw away food Isomegalen diagram of before, showing more comprehensive relationship between temperature and body length between developmental periods; according to pupa shell pupa form of change will be divided into 13 sub-pupal stage, the pupae and 15-35 °C Asian stage at different times at which summarized.The second part is the study the differential gene expression during pupal metamorphosis for age estimation of forensically important Calliphora Chrysomya megacephala. establish laboratory popu Lations, access to the bu Lk of the gold fly pupae at different temperatures for the bu Lk of the gold fly pupae were sampled twice a day, and then detecting the pupal stage 4 gene hsp 70, ecr, white and tbp expression at different times Level. The resu Lts showed that: From the point of view the level of the whole developmental duration, hsp 70 present in the pupal stage throughout the developmental stages first and then decreased again increased downward trend, ecr showing the overall downward trend, white showing increased first downward trend, tbp It showed an overall decline, but increased the downward trend appeared in the middle. At different temperatures, with the trend of a gene also vary.