Abstract: In order to reveal the molecular mechanisms in the process of homologous chromosome recombination, spermatocytes ofmouse were used to observe the localization relationship between RAD21L and REC8 and the recombination intermediates RAD51 and MSH4 by high-resolution microscope (3D-SIM), and to compare the correlation of the recombination intermediates between RAD21L and REC8. The results showed that RAD21L was more likely to express in the vicinity of recombinant intermediates than that of REC8, and even express insome parts of homologous chromosomes that had not yet been linked. Interestingly, these parts were just where recombinant intermediates existed. It is believed that RAD21L acted indirectly on the recombination of homologous chromosomes. When DSBs occurred on the chromosome, RAD21L would accumulate and fix around DSBs to ensure the successful repair of DSBs, while the repair of DSBs was a secondary function for REC8.

Key words: mouse, homologous chromosome recombination, DSBs repair, cohesin, RAD21L