Fig. 6

Nuclear progestin receptors are up-regulated by estradiol.

A to P: Pgr immunohistochemistry (red) on tg(cyp19a1b-GFP) transgenic larvae (green) with DAPI counterstaining (blue) in the anterior (PPa) and posterior (PPp) preoptic area in two different control larvae (A–D and I–L) and two E2-treated larvae (E–H and N–P). A–D: Control larva treated with EtOH: Although the Pgr staining is widely distributed, not all cells are positive as shown by DAPI counterstaining. Only a few cyp19a1b-GFP expressing radial glial cells are visible and some of them express Pgr (D). E–H: Larva treated with 10^-8 M of 17β-estradiol: At exactly the same level than in control (A–D), one can see that a majority of cells express Pgr as shown by the DAPI counterstaining. Furthermore, Pgr staining intensity is stronger than in controls. The estrogenic treatment also leads to an increase in the number of cyp19a1b-GFP positive radial glial cells expressing Pgr (H). Pictures in E and F were taken with the same exposure time than A and B, respectively. I–L: Control larva treated with EtOH shown at higher magnification in the posterior preoptic area. The Pgr staining is clearly detectable in some cells as indicated by the DAPI counterstaining. As shown by the merge picture in L, the cyp19a1b-GFP radial glial cells do not express Pgr. M–P: Larva treated with 10^-8 M of 17β-estradiol (E2) in the exactly the same region than in I–L. Pgr is expressed in a large majority of cells and the staining intensity is clearly much stronger than in control larvae. Furthermore, all cyp19a1b-GFP positive radial glial cells also express Pgr. Pictures in M and N were taken with the same exposure time than I and J, respectively. Scale bars: 60 μm (A, B, C, D, E, F, G and H); 30 μm (I, J, K, L, M, N and O).