Figure 2

Cholesterol uptake is elevated in the genitalridges. (A) A transverse tissue slice dissected from an E9.5 embryo. Genital ridge and non-ridge tissue were isolated as shown. (B) Hmgcr expression in ridge and non-ridge tissue was similar in three independent quantitative RT-PCR experiments. Ridge Hmgcr levels were set to an arbitrary value of 100. (C) Unstained (background fluorescence) and Filipin stained E9.5 tissue. (D) The average filipin staining intensity of midline and ridge tissue was calculated by measuring pixel intensity in three midline and three lateral (colored spots in C) regions per slice and normalizing to the average ridge staining (set to 100%). (E) A cholesterol bioprobe gave an elevated response when touched to ridge as compared to midline tissue. (F) Summary of bioprobe data taken from four slices. Midline response was normalized to the ridge response (100%). Scanning TOF-SIMS of an E9.5 slice imaged for (G) phosphatidylcholine (m/z = 184) or (H) cholesterol (m/z = 369). E9.5 tissue pre-treated for 30 minutes with soluble cholesterol and imaged for (I) phosphatidylcholine or (J) cholesterol. Arrowheads indicate the position of the genital ridges. In all panels "n" = number of slices and error bars are s.e.m. Scale bars are 100 μm.