In the previous article we introduced two concepts in sémiotique to be used in the area of comparative physiology and biochemistry; synchronie and diachronie. The former describes a snapshot of a complex biological system taken at a certain time point, whereas the latter describes the dynamic aspect of a complex biological system through time. In order to achieve the latter it is necessary to study the time-dependent change of system parameters such as kinetics of protein expression. We have established a methodology to trace the dynamic aspect of protein expression for as many as several hundred proteins and called it “proteomic trajectory mapping.” In this follow-up review we will explain proteomic trajectory mapping in detail which is essential for studying the diachronic aspect of living things.
In general, it is known that the insect egg is very difficult to prepare for transmission electron microscope (TEM). Especially, the one of the most difficult specimen is the mature eggs of silkworm, Bombyx mori. It is important that the chorion was removed gently by the needles before fixation, and the processes of dehydration and substitution were spent thoroughly by the conventional method. These samples could be easy to obtain the ultrathin sections, but there were no structures in the yolk cell cytoplasm which are thought to be an artifact by preparation process. The high-pressure freezing in combination with the freeze substitution methods were examined to observe the ultrastructure of B.mori egg without losing yolk components. Many lipid droplets and glycogen granules were well preserved in the yolk cell cytoplasm. However the ultrastructure of yolk cell cytoplasm in the prefixed egg with chemical fixative before freezing tended to be damaged, compared with that of the non-fixed egg. The ultrastructure of yolk cell cytoplasm may be influenced by chemical fixation. It is demonstrated that the high-pressure freezing in combination with the freeze substitution methods are suitable for the difficult specimens to prepare by the conventional preparation methods for TEM.