Confocal imaging of the exo- and endoskeleton of Protura after nondestructive DNA extraction

Abstract

In certain minute arthropods, such as Protura, species determination cannot be performed unambiguously without clearing and slide mounting of specimens. This causes an awkward dilemma for scientists conducting molecular research, since conventional DNA extraction entails destruction of the whole specimen. Thus, single individuals can be used either to obtain molecular data or for determination purposes. Such molecular datasets are thus dependent on determination of co-habitant specimens, and entries in GenBank are highly prone to misidentification. To overcome this problem, we applied a non-destructive DNA extraction method and subsequently used confocal autofluorescence imaging to analyse and document cuticular characters of the same specimens. Alternatively the preparations can be examined by conventional microscopy. Our results show that the used non-destructive extraction method results in completely clear cuticular remains and does not significantly affect autofluorescence or shape. The acquired confocal image stacks and resulting volume renderings are useful to visualise, reconstruct and quantify structures for taxonomic purposes but also for morphological investigation of special cuticular structures such as the head endoskeleton of hexapods.

Keywords

• Cuticle
• CLSM
• autofluorescence
• Congo red