Observation of central nervous system and body fluid viscosity of Trypoxulus dichotomus (Coleoptera) in the pupal stage using 9.4-T MRI.

Motivation: To clarify the misters metamorphosis process of holometabolous insects, which might lead to innovative technology of regenerative medicine Goal(s): Elucidation of the process focusing on the central nervous system, and fluid viscosity relation to protein composition in the body fluid. Approach: Consecutive observation of the tissue change by DTI and T2 mapping, as well as protein analysis by absorbance measurement and electrophoresis, was performed in the pupa of Trypoxylus dichotomus. Results: The nerve system remained unchanged during metamorphosis period, while unimodal T2 changed, which may have related to protein composition, peaking 3-4 days after pupation were recognized. Impact: The present results show that the nerve fibers and ganglia remain, while other tissues are developed. These findings give new insight into the relationship between the central nerve system and metamorphosis in holometabolous insects.