Development Profile Of Pupal Hemolymph Soluble Proteins In Two Species Of Necrophagous Flies

Objective: To study the development profile of pupal hemolymph soluble proteins of Lucilia sericata and Chrysomya megacephala under different temperatures, and to provide scientific data for deducing the postmortem interval (PMI) in criminal investigation.Methods: The adults of L. sericata and C. megacephala were collected from the outdoors. The experiment was done with offspring of the third generation. The eggs of adult flies were maintained at 24℃, 28℃, 32℃and 50~60% RH. The period of light and food were kept unchanged.The beginning of the prepupal stage was marked as the 0 day, and 20 pupae were collected and weighed at fixed time. All the values of weights data were recorded with the form of mean±SD, which were used to establish the growth curves of pupal mean weight and age under different temperatures.The pupal hemolymph was collected at fixed time, whose absorbance at 595nm (A595) was examined with Bradford method. And the according protein concentration was worked out to establish the growth curves of protein concentration and age under different temperatures.The development profile of pupal hemolymph soluble proteins was analyzed by the SDS-polyacrylamide gel electrophoresis, including the molecular weight and concentration of every band. And use the software of SPSS11.5 to establish linear regression model of protein concentration and age under different temperatures.Results:1 the change of pupal weightAt a certain constant temperature, the pupal weight decreased obviously during the early period, after that it decreased slightly except for the quick decrease in the end of the pupal stage. The changing fitted well with a cubic model. The change was inversely proportional to different temperature, namely, faster in higher temperature and slower in lower temperature.2 the relationship between protein concentration and pupal ageAt a certain constant temperature, the pupal protein concentration decreased gradually and the linear equations were fitted the relationship between the protein concentration and age. It shows obviously decreasing in higher temperature.3 the development profile of pupal hemolymph soluble proteinsSeveral distinct component bands were resolved under different temperatures. The concentration of each protein band changed with development in pupal stage acts a certain pattern.3.1 L. sericataSeventeen distinct component bands with a molecular weight about 11~230KD were observed. The concentration of band A(230KD), D(85KD), L(28KD), M(25KD) and N(20KD) decreased gradually with the pupal age, which could be fitted by the linear equations.3.2 C. megacephalaFifteen distinct component bands with a molecular weight about 14~230KD were resolved. The concentration of band A(230KD), D(78KD), G(38KD) and H(32KD) decreased gradually with the pupal age, which could be fitted by the linear equations.Conclusions:1 The pupal weight decreased obviously during the early period, since then it decreased slightly except for the quick decrease in the end of the pupal stage. The change was obvious in higher temperature.2 The pupal protein concentration decreased gradually and the linear equations were fitted the relationship between the protein concentration and age. It shows obviously decreasing in higher temperature.3 Seventeen distinct component bands were resolved in pupal hemolymph of L.sericata. The concentration of band A(230KD), D(85KD), L(28KD), M(25KD) and N(20KD) decreased gradually with the pupal age. Fifteen bands did C.megacephala. The concentration of band A(230KD), D(78KD), G(38KD) and H(32KD) decreased gradually with the pupal age. Both of these bands could be fitted well with the linear equations.