GLIDING MOVEMENTS IN MYXOCOCCUS-XANTHUS

Prokaryotic gliding motility is described as the movement of a cell on a solid surface in the direction of the cell's long axis, but its mec hanics are unknown, To investigate the basis of gliding, movements of individual Myxococcus xanthus cells were monitored by employing a vide o microscopy method by which displacements as small as 0.03 mu m could be detected and speeds as low as 1 mu m/min could be resolved. Single cells were observed to glide with speeds varying between 1 and 20 mu m/min. We found that speed variation was due to differences in distanc e between the moving cell and the nearest cell. Cells separated by les s than one cell diameter (0.5 mu m) moved with an average speed of 5.0 mu m/min, whereas cells separated by more than 0.5 mu m glided with a n average speed of 3.8 mu m/min. The power to glide was found to be ca rried separately at both ends of a cell.