Expression of growth-differentiating factor 9 and its type 1 receptor in human ovaries.
The expression of growth-differentiating factor 9 (GDF9) has not been studied in ovaries from girls and human fetuses nor has its receptor transforming growth factor-beta1 receptor (TGFbetaR1) been investigated in ovaries of girls/women. The aim of this study was to fill these gaps. Ovarian samples were obtained from 16 human fetuses at 21-35 gestational weeks and from 34 girls/women aged 5-39years. These specimens were prepared for immunohistochemical staining of the GDF9 and TGFbetaR1 proteins. Reverse transcription polymerase chain reaction was used to detect GDF9 mRNA transcripts and in-situ hybridization to localize TGFbetaR1 mRNA transcripts. Positive staining for the GDF9 protein was identified in oocytes and granulosa cells in all samples tested. GDF9 mRNA transcripts were present in all samples. Protein expression of TGFbetaR1 was identified in granulosa cells in all samples. Oocyte staining was identified in samples from girls/women but in only one fetal sample. TGFbetaR1 mRNA transcripts were identified in granulosa cells and oocytes in 50% of the samples from fetuses aged over 22 gestational weeks and in samples from girls/women. The detection of GDF9 and TGFbetaR1 at both at the protein and mRNA levels suggests that GDF9 may have functions in human preantral follicles.