Research Article

Is Evolution of Mating Preferences Inevitable? Random Mating in the Multisex System of Tetrahymena thermophila

Figure 1

Experimental design. (a) Strain construction: three parental strains obtained from the Tetrahymena stock center (Table 1) were individually subjected to a genomic exclusion cross with the strain A*III [13] to construct an array of drug resistant progeny strains of sexes II, IV, V, and VII (shown here as Arabic numbers for convenience). Drugs are represented by M: 6-methylpurine; C: cyclohexamide; P: paromomycin. These 12 progeny strains (Table 1) were used to set up experimental trials. (b) Mate choice assay: for each triplet of sexes, separate trials were conducted, in which the resistant genetic backgrounds alternated between the three sexes. Thus, each trial contained a unique combination of progeny strains that were allowed to compete for mating partners.
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(a)
201921.fig.001b
(b)