FIGURE 2.

Histochemistry and enzyme cytochemistry of the cutaneous MCs in WT and Prss31-null B6 mice. A–D, identification of CAE⁺ cutaneous MCs. Sections of the ears of WT (A and B) and Prss31-null (C and D) mice were subjected to H&E histochemistry (A and C) and enzyme cytochemistry (B and D). No ultrastructural abnormality was detected in the ears of the Prss31-null mice, as also occurred in the jejunum (data not shown). All MCs in WT B6 mice are CAE⁺ due to their granule storage of large amounts of the chromosome 14C3 family members mMCPs 1–5 and 8–10. WT and Prss31-null B6 mice constitutively had similar numbers of CAE⁺ MCs (red cells highlighted by black arrows) in their ears (B and D). Thus, Prss31 is not essential for the recruitment of MC-committed progenitors into the ear or for their development into mature MCs, as anticipated. For size comparison, the red arrows in B and D point to the 10-μm magnification bars.