Fig. 1. Lunatic fringe is expressed in the granulosa cells and theca. Whole-mount thick section ISH of wild-type 42-day-old ovary was carried out using antisense digoxigenin-labeled RNA gene-specific probes. (A) Lfng-specific probes including 3' untranslated sequences and Lfng transcripts were detected in follicles from type 3 to preovulatory in granulosa cells, but not in oocytes or interstitial cells. (B) Lfng exon only probe. Transcripts were detected in the theca and in the vasculature (red arrow indicates positive blood vessel), a band of Lfng transcripts surrounding small follicles was observed (inset). (C) Rfng was expressed transiently in the granulosa cells of antral follicles (arrow). (D) Mfng transcripts were only detected in the vasculature (red arrow). (E) RT-PCR from total ovary RNA demonstrates the presence of Mfng and Rfng transcripts. E9.5 represents total E9.5 embryo control; L+/+ represents total ovary RNA from a 42-day-old wild-type animal; mock represents no RT control. (F) RT-PCR of Lfng and Gdf9 transcripts from total RNA from GV and MII stage oocytes. E9.5, total embryo control; MW, 100 bp ladder. Scale bars: 100 µm.