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Fig. 3. Reduced TrkA enhancer activity in P0 Brn3a-null or
double-null trigeminal ganglia. Low (A1-A4) and high (B1-B4) magnification
pictures of ß-galactosidase activity driven by the TrkA minimal
enhancer, showing that Brn3-null (A3,B3) and double-null (A4,B4)
ganglia have reduced ß-galactosidase activity compared with control
(A1,B1) and Bax-null (A2,B2) ganglia, respectively. (C1-C4, arrows)
Individual ß-galactosidase positive cells from each genotype show
apparently reduced ß-galactosidase activity in cell bodies of
Brn3a-null (C3) and double-null (C4) ganglia, but normal activity in
control (C1) and Bax-null (C2) ganglia. (D1-D4, arrows) A second set
of ß-galactosidase-positive trigeminal ganglia neurons from an
independent group of mice, showing that reduced TrkA enhancer
activity in Brn3a-null (D3) and double-null (D4) ganglia is
consistent, compared with control (D1) and Bax-null (D2) ganglia.