The microtubule cytoskeleton is involved in key cellular processes, including cellular polarization and transport. Microtubules are composed of repeating α and β tubulin dimers. TUB2 is an essential yeast gene that encodes β-tubulin. Microtubule polymerization dynamics in yeast are regulated by +TIPs, like Bim1p and Bik1p. Genetic analysis of multiple genes concurrently allows for the identification of interactions between genes. This study seeks to investigate interactions between Bim1p/Bik1p and Tub2p by using random spore analysis (RSA) to search for synthetic interactions caused by the association of bim1Δ/bik1Δ and tub2 mutants. Using the RSA results and a set of criteria, tub2 mutants were grouped into interaction types, such as synthetic sensitive and synthetic enhanced. This study also investigated associations between a tub2 mutation’s interaction type and other tub2 phenotypes, which revealed an association between synthetic sensitivity and cold sensitivity for tub2 and bik1Δ. A protein model of tub2 mutations in β-tubulin was also used to demonstrate that tub2 mutations that did not interact with bim1Δ/bik1Δ tended to cluster together in the same location on β-tubulin. This study shows that RSA can be used to identify synthetic interactions, which can be analyzed in terms of protein structure and relationship with other traits of the mutations.

The microtubule cytoskeleton is involved in key cellular processes, including cellular polarization and transport. Microtubules are composed of repeating α and β tubulin dimers. TUB2 is an essential yeast gene that encodes β-tubulin. Microtubule polymerization dynamics in yeast are regulated by +TIPs, like Bim1p and Bik1p. Genetic analysis of multiple genes concurrently allows for the identification of interactions between genes. This study seeks to investigate interactions between Bim1p/Bik1p and Tub2p by using random spore analysis (RSA) to search for synthetic interactions caused by the association of bim1Δ/bik1Δ and tub2 mutants. Using the RSA results and a set of criteria, tub2 mutants were grouped into interaction types, such as synthetic sensitive and synthetic enhanced. This study also investigated associations between a tub2 mutation’s interaction type and other tub2 phenotypes, which revealed an association between synthetic sensitivity and cold sensitivity for tub2 and bik1Δ. A protein model of tub2 mutations in β-tubulin was also used to demonstrate that tub2 mutations that did not interact with bim1Δ/bik1Δ tended to cluster together in the same location on β-tubulin. This study shows that RSA can be used to identify synthetic interactions, which can be analyzed in terms of protein structure and relationship with other traits of the mutations.