Oxytricha, a hypotrich having two macronuclei, was ultracentrifuged at a force of about 50,000 times gravity for five to ten minutes. It was found that the macronuclei and micronuclei are of different relative densities, the macronuclei being drawn to the centrifugal pole by high-speed centrifuging, while the micronuclei appear to be only slightly affected by the forces used. Oxytricha may be stratified and torn in two, and the fragments are able to move about independently of each other. Fragments without marconuclei are capable of normal activity, the external body form being regained in from fifteen minutes to an hour or more, depending upon the amount of distortion of the fragments. The micronuclei are able to divide while undergoing ultra-centrifugation. Small fragments containing both macronuclei and only a slight amount of cytoplasm are unable to recover, and soon die.
Proceedings of the Iowa Academy of Science
©1940 Iowa Academy of Science, Inc.
Kirshenblit, Harold W.
"Effects of Ultracentrifuging Oxytricha,"
Proceedings of the Iowa Academy of Science, 47(1), 417-417.
Available at: https://scholarworks.uni.edu/pias/vol47/iss1/105