All organisms live in changeable, stressful environments. It has been reported that exposure to low-dose stresses or poisons can improve fitness. However, examining the effects of chronic low-dose chemical exposure is challenging. To address this issue we used temperature sensitive mutations affecting the yeast cell division cycle to induce low-dose stress for 40 generation times, or more. We e...

During DNA replication, stalled replication forks and DSBs arise when the replication fork encounters ICLs (interstrand crosslinks), covalent protein/DNA intermediates or other discontinuities in the template. Recently, homologous recombination proteins have been shown to function in replication-coupled repair of ICLs in conjunction with the Fanconi anemia (FA) regulatory factors FANCD2-FANCI, ...

In the absence of core nonhomologous end-joining (NHEJ) factors, Ab gene class-switch recombination (CSR) uses an alternative end-joining (A-EJ) pathway to recombine switch (S) region DNA breaks. Previous reports showing decreased S-junction micro-homologies in MSH2-deficient mice and an exonuclease 1 (EXO1) role in yeast microhomology-mediated end joining suggest that mismatch repair (MMR) pro...