Macronuclear development in conjugants of Tetrahymena thermophila, which were artificially separated at meiotic prophase.

Conjugant pairs of Tetrahymena thermophila were mechanically separated by vigorous pipetting at the early stages of meiotic prophase. The complete sequence of conjugational nuclear events including the appearance of pronuclei, development of the new macronuclei (postzygotic development), and resorption of the old macronuclei was observed in the separated cells, without pronuclear exchange. The pronuclei in the separated cells were recognised by the presence of components of the extranuclear cytoskeleton, which were labelled with anti-tubulin and anti-fenestrin antibodies in the same way as in undisturbed conjugants.

Contents of myosin heavy chains in denervated slow and fast rat leg muscles.

The total content of myosin heavy chain (MHC) and individual MHC isoforms were studied in 14-day denervated rat leg muscles: the slow-twitch (soleus) and fast-twitch (extensor digitorum longus and gastrocnemius) by biochemical methods. The weight of the denervated muscles decreased by about 50%, as compared to the control muscles. In all denervated muscles the total content of MHCs decreased, more so in the slow than in the fast muscles.