In situ BrUTP incorporation in a gonad to show rRNA synthesis activity. (a) Incorporation of BrUTP was detected by an anti-BrUTP antibody conjugated with fluorescence dye Alexa 594. Arrowheads indicate the signal from BrUTP incorporation. (b) DNA staining of the same gonad. Note the increased BrUTP incorporation in germ cells at the pachytene zone of meiosis. The scale bar indicates 10 μm.
