Figure 6. A model of the MSCI checkpoint: The physical sequestration of DDR factors from autosomes to the XY body is a critical checkpoint in meiosis progression and gamete development.

At the onset of MSCI, DDR factors (shown as red spheres) are sequestered from autosomes to the sex chromosomes. The physical sequestration of DDR factors on/at a sex chromosome-specific chromo-nuclear compartment, the XY body, is a critical step in the MSCI checkpoint in the mid pachytene stage of meiotic prophase I. While the MSCI checkpoint ensures meiotic stage progression in normal meiosis, the abolishment of MSCI enables the ectopic retention of DDR signals on/at autosomes; these, in turn, trigger complete meiotic arrest and cell death in response to the checkpoint.

See also Figure S6.