Late morphogenesis vibrissa follicle abnormalities in <i>Trps1^Δgt/Δgt</i> embryos.

<p>(A) <i>Trps1^+/+</i> and <i>Trps1^Δgt/Δgt</i> embryos at E16.5. Note the reduced number of vibrissae follicles and decreased size of the maxillary region (white brackets) in mutant embryos. (B) <i>Trps1^+/+</i> embryos have five rows of vibrissae (rows A–E), whereas <i>Trps1^Δgt/Δgt</i> embryos have four rows due to a convergence of rows C and D. (C–H) Hematoxylin and eosin staining of transverse <i>Trps1^+/+</i>, <i>Trps1^+/Δgt</i> and <i>Trps1^Δgt/Δgt</i> whisker pad sections at E16.5–E18.5 revealed small and irregularly spaced vibrissae follicles in heterozygous and homozygous mutant embryos. (I–L) Hematoxylin and eosin staining of sagittal <i>Trps1^+/+</i> and <i>Trps1^Δgt/Δgt</i> head and dorsal skin sections at P0. Note the absence of hair follicles in the upper and lower jaws (black arrows) (I,J) and reduction in pelage follicle density (K,L) in mutant mice. Peg, epithelial peg; DC, dermal condensate. Scale bars, 100 µm.