Figure 3.

Total zinc content does not increase in individual somatic cells during follicle development.A, elemental maps of iron, copper, and zinc for single somatic cells isolated from primordial, primary, and secondary stage follicles and analyzed by synchrotron-based x-ray fluorescence microscopy. The color scale bar represents the minimum and maximum elemental contents (μg/cm²) of each element. The scale bar represents 2 μm. B, quantification of total atom number of iron, copper, and zinc from the elemental maps, with whole somatic cell area as the ROI. C, quantification of elemental concentration in μg/cm² of iron, copper, and zinc in the somatic cells from the elemental maps. D, comparison of iron, copper, and zinc concentrations in single oocytes versus individual somatic cells from the three follicle stages. Data represent mean values (SD). N = 17 pfGCs, 14 primary follicle GCs, 10 secondary follicle GCs (A–C). Letters denote statistically significant differences between developmental stages of each element by two-way ANOVA with Tukey’s multiple comparison test (B and C, p < 0.05) (C: Secondary to primary stage zinc concentration P_adj < 0.0001) or Śídák’s multiple comparisons test comparing between the two cell types (D, ∗p= 0.0152, ∗∗∗p= 0.0002, ∗∗∗∗p< 0.0001). See Table S3 for corresponding quantification. GC, granulosa cell; pfGC, primordial follicle granulosa cell; ROI, region of interest.