Fig. 2. Phase-contrast video micrographs of rotational movement of bull sperm flagellum observed from the sperm long axis. (A) Clockwise movement. (B) Counterclockwise movement. The time interval between successive images is 1/60s.
Sperm rotation around its long axis
The rotational movement of a spermatozoon around its longitudinal axis was investigated by two methods: by observing a spermatozoon attached vertically to a coverslip by the tip of its head, and by observing a spermatozoon freely swimming in a medium by means of 'double-focal microscopy', which yielded simultaneous images at two different focal planes. Similar results were obtained by these two methods. Sea urchin, starfish, medaka, human, golden hamster and bull spermatozoa rolled in both clockwise and counterclockwise directions, although there was a large difference in the proportion of spermatozoa rolling in each direction in the different species. The majority of sea urchin and starfish spermatozoa rolled in a clockwise direction when an observer viewed the cell from its anterior end, whereas the majority of medaka, golden hamster, human and bull spermatozoa rolled in a counterclockwise direction relative to the same observer.
Source: ROTATIONAL MOVEMENT OF A SPERMATOZOON AROUND ITS LONG AXIS
BY SUMIO ISHIJIMA, MIYAKO S. HAMAGUCHI, MASAKAZU NARUSE, SANAE A. ISHIJIMA* AND YUKIHISA HAMAGUCHI
Biological Laboratory, Tokyo Institute of Technology, O-okayama, Meguro-ku, Tokyo 152, Japan
Accepted 16 September 1991