Figure 1.—

spo7Δ has genetic interactions with mps3 alleles specifically defective at SPB duplication. (A) Wild-type (OCF1533-2C), spo7Δ (KW660), mps3-1 cells containing pURA3-MPS3 (KW661), and mps3-1 spo7Δ cells containing pURA3-MPS3 (KW548) were plated by serial dilution on control media (SC) or plates containing 5-FOA at 23°. The presence of 5-FOA allows only cells lacking the URA3 gene to survive. (B) Wild-type (OCF1533-1A), spo7Δ (JCY565), mps3-F592S cells containing pURA3-MPS3 (KW658), and mps3-F592S spo7Δ cells containing pURA3-MPS3 (KW576) were plated by serial dilution on control media (SC) or plates containing 5-FOA at the indicated temperatures. (C) Summary of mps3 mutant alleles, their effects on SPB duplication, and their effects on cell growth in the absence of Spo7p. The Mps3p transmembrane domain (TM) and SUN domain are indicated. The “x” marks the approximate location of point mutations within the SUN domain. ++, +, and − denote a “strong defect,” “moderate defect,” and “no defect,” respectively. Data for SPB defects are from Jaspersen et al.(2002, 2006) and Bupp et al. (2007). Data for genetic interactions with spo7Δ are from Figure 1, A and B, and Figure S1.