Growth phenotype of gene-disruption mutants of Arp2/3 complex subunits. (A) Tetrads from heterozygous diploid strains Δarc15 (RLY514), Δarc18 (RLY515), Δarc19 (RLY344), Δarc35 (RLY343), Δarc40 (RLY722), Δarp2 (RLY184), and Δarp3(RLY180) after 5 days of growth on YPD at room temperature. The two large colonies in each tetrad always corresponded to wild-type spores, and the two small or missing colonies corresponded to disruption spores. Arrows point to viable gene-disruption colonies. (B) Terminal colony morphologies of a representative Δarc35 spore (a) and a representative Δarc40 spore (b).