(en) Isomyosins of the two middle ear muscles of rabbit have been separated by electrophoresis in non-dissociating conditions. Tensor tympani has four isomyosins called MM1 to MM4 by order of decreasing mobility. Stapedius has two isomyosins, similar to MM1 and MM4. MM1 and MM2 have the same mobility than FM2 and FM3, fast isomyosins observed in psoas. MM4 has the same mobility than IM, a slow isomyosin observed in extensor digitorum longus. MM3 is absent in soleus, psoas or extensor digitorum longus. Slow myosin (SM) of soleus and fast myosin (FM1) of psoas are not observed in middle ear muscles.
Moraru, I., Beckers-Bleukx, G., & Maréchal, G. (1984). The Isomyosins of Rabbit Middle-ear Muscles. Archives Internationales de Physiologie et de Biochimie, 92(5), 385-390. https://doi.org/10.3109/13813458409080615 (Original work published 1984)