Homologous chromosome recombination in meiotic prophase is required for orderly chromosome segregation. Recombination is preceded by chromosome prealignment and the scheduled formation of DNA double-strand breaks (DSBs), followed by a RAD51-mediated search for homologous DNA sequences and the formation of heteroduplexes involving DNA strands of homologous chromosomes at early stages of meiotic prophase (leptotene and zygotene). Polymerisation of the synaptonemal complex (SC), a meiotic-specific proteinaceous structure, stabilises these connections and completes homologous chromosome synapsis. A small proportion of DSBs (at least one per chromosome pair) is repaired as crossovers (reciprocal exchanges between homologues). The sites of crossing over can be visualised in mid-meiotic prophase (pachytene) as late recombination nodules containing MLH1 (mismatch repair protein), and at diplotene-diakinesis as chiasmata. Sister chromatid cohesion beyond the chiasmata holds homologues together at metaphase-I, ensuring proper orientation and orderly segregation12.