Given the significant reduction in transcription observed in CDK12−/− oocytes (Fig. 4), we examined the expression of specific developmentally relevant classes of mRNAs encoding translational factors [15] (4E-BP1, eEF2, eIF4G1) and markers associated with premature ovarian failure [23–26] a phenotype observed in (Fig. 2) (POF; RPS26, FIGLA, GDF9, AIRE, FMRP1). The gene discussed is GDF9; the disease is primary ovarian failure.