Fig. 5

Enhancing homologous recombination efficiency in O. polymorpha. A Colony PCR of red/pink clones. PCR products of three different lengths were obtained from the genome of red/pink colonies, indicating the presence of three different genotypes in positive clones upon addition of donor DNA (M: Marker; lanes 1–2: 2700 bp of NHEJ products; lanes 3–5: 2300/2400 bp of semi-HR products; lanes 6–8: 1000 bp of HR products.). B Schematic representation of the three genotypes (HR, semi-HR, and NHEJ) presented in pink clones. C Effect of overexpressing HR-related protein genes RAD51 and RAD52 from O. polymorpha and P. pastoris, as well as deletion of the NHEJ key gene KU70, on HR efficiency (n = 52). D Effects of deletion of the KU70 gene on strain growth vitality. The data are represented as mean ± SD. (n = 3 biologically independent samples). Black asterisks indicate statistical significance as determined using paired t test (***p < 0.001; ns.: no significant difference)