AR is present in oocytes, GCs, and theca cells of preantral follicles, and
overall expression and nuclear localization of AR increases in the presence of
DHT. (a) AR expression (green) in mouse prepubertal mouse ovary on day 17
postpartum. DAPI-labeled nuclei are blue. Scale bar = 50 µm. White
dotted lines indicate basal lamina surrounding follicles. (b) Rabbit
immunoglobulin G control. Scale bar = 25 µm. (c) Strong labeling of
ooplasm (white arrow) and GC cytoplasm (white arrowhead) in primordial and
transitional follicles. Scale bar is 25 µm. (d–m) Quantification
of AR in formalin-fixed, paraffin-embedded sections of follicles cultured in
the absence (d–h) and presence (i–m) of DHT. (d and i) Confocal
image of follicle showing expression of AR (green) and DAPI-labeled nuclei
(blue). Scale bars = 25 µm. White dotted box defines enlarged images
(e–h and j–m). Images were imported into ImageJ and split into
red-green-blue channels. Blue DAPI-labeled nuclei (e and j) were thresholded (f
and k; where white is DAPI positive and black DAPI negative), and nuclei were
outlined using the “Analyze Particles” command (f and k). In the
green channel, AR labeling (g and l) was thresholded (with the same threshold
maintained for all follicles), the nuclear outlines were overlaid, and the area
of labeling exceeding the threshold was measured within the nuclear outlines (h
and m), and for the GC layer as a whole. Yellow arrows (h) indicate nuclei with
little nuclear AR, and yellow arrowheads (m) indicate nuclei with strong
nuclear AR. White arrowheads (l and m) show strong AR expression in theca cell
nuclei. Values were plotted and compared between treatments using a
Mann-Whitney test. Overall AR protein expression in the GC layer was
significantly increased after 24 hours (n) and 72 hours (p) culture in the
presence of DHT. Nuclear localization of AR was also significantly increased in
the presence of DHT at 24 hours (o) and 72 hours (q). 1°+, primary stage
with second layer of GCs appearing; 2°, secondary stage; e1°,
early primary; ose, ovarian surface epithelium; p, primordial; T, theca; t,
transitional.