Tubulin evolution: an electrophoretic and immunological analysis

This paper summarizes a survey of the electrophoretic behavior of the tubulins of 23 species (mostly protists) as well as their reactivity towards 4 anti-tubulin antibodies (raised against two ciliate tubulins and two vertebrate ones). Some generalizations concerning the relative migration rates of alpha VS beta tubulin could be made, in particular the alpha/beta inversion, first described in Physarum was extended to several ciliates. Antivertebrate tubulin antibodies displayed a very broad spectrum of reactions, reacting with virtually all the species tested. They appear to correspond to auto-antibodies no exclusively directed against species specific determinants. In contrast, the two anti-ciliate tubulin antibodies displayed a narrow species specificity reacting only with a limited subset of protists. They were shown to be specific for a small number of immunological determinants present on ciliate tubulins. This allowed a rough evaluation of evolutionary relatedness between the various groups of protists analyzed. The results are discussed within the framework of a number of published phyllogenies and shown to be in striking agreement with some of the schemes.