BRD2 and cyst: PF assembly is reduced in newborn rat ovaries treated with AMH while oocyte number is greater than controls.45 A study using mouse ovary organ culture implicates FSH in promoting cyst breakdown and PF formation.46 Finally, a study in the mouse ovary showed that cyst breakdown requires the activity of c-Jun N-terminal kinases (JNKs) that are likely necessary to downregulate E-cadherin expression in oocytes.47