Crossover or non-crossover outcomes: tailored processing of homologous recombination intermediates

DNA breaks may arise accidentally in vegetative cells or in a programmed manner in meiosis. The usage of a DNA template makes homologous recombination potentially error-free, however, recombination is not always accurate. Cells possess a remarkable capacity to tailor processing of recombination intermediates to fulfill a particular need. Vegetatively growing cells aim to maintain genome stability and therefore repair accidental breaks largely accurately, using sister chromatids as templates, into mostly non-crossovers products. Recombination in meiotic cells is instead more likely to employ homologous chromosomes as templates and result in crossovers to allow proper chromosome segregation and promote genetic diversity. Here we review models explaining the processing of recombination intermediates in vegetative and meiotic cells and its regulation, with a focus on MLH1- MLH3-dependent crossing-over during meiotic recombination.

Automated summary

This article reviews models explaining the processing of recombination intermediates in vegetative and meiotic cells and its regulation, focusing on MLH1-MLH3-dependent crossing-over during meiotic recombination. The summary emphasizes the importance of accurate recombination for genome stability in vegetative cells and the role of crossovers in promoting genetic diversity during meiosis.