BLM staining persists on Mlh3^−/− pachytene spermatocyte chromosome cores. Zygotene (zyg) and pachytene (pach) spermatocytes from both Mlh3^+/+ and Mlh3^−/− mice stained with SYCP3 (red), BLM (green), and CREST (pink). BLM accumulates normally in zygonema in both cohorts of mice; however, it is still present in high numbers in pachynema in the Mlh3^−/− cells but not in Mlh3^+/+ cells.