Arrangement and dynamics of spindle structures in crane fly spermatocytes seen with video-enhanced contrast differential interference contrast microscopy

This is a report on the arrangement and dynamic behaviour of microtubule fibres investigated by video-intensified microscopy (Allen Video Enhanced Contrast —Differential Interference Contrast, AVEC-DIC) in spindles of living crane fly spermatocytes. The spindle was found to contain numerous fibrils, each fibril probably consisting of several microtubules. The fibrils are oriented between the poles and, due to slight inclinations, towards each other, frequently form arrowhead-like structures or points of intersection. This leads to an overall lattice-like arrangement. The fibrils display flickering motions visible in real time recordings. The observations are discussed in relation to ultrastructural data on chromosome fibre architecture from previous studies.