Developmental rearrangements associated with a single type of expressed alpha-tubulin gene in Tetrahymena.

Southern blotting analyses with diverse heterologous probes indicate that there is only a single type of alpha-tubulin gene in the ciliated protozoan Tetrahymena thermophila. Comparisons of the germ-line configuration of alpha-tubulin sequences in the transcriptionally inert micronucleus with the somatic configuration in the transcriptionally active macronucleus indicate that rearrangements involving breakage and rejoining of sequences flanking both sides of the alpha-tubulin gene accompany macronuclear differentiation.