Figure 3
From: The precision of axon targeting of mouse olfactory sensory neurons requires the BACE1 protease
Axon targeting of OSNs is altered in BACE1-deficient mice.
(a) Immunostaining using an antibody against the OR M71 revealed that M71-expressing OSN axon fibers converge to one specific glomerulus in each half bulb in wild type (BACE1 +/+) mice as indicated by the arrow. In BACE1 heterozygous (BACE1 +/−) mice (b) and BACE1 null mice (BACE1 −/−) (c), M71-expressing OSN axons project more glomeruli than one glomeruli per half bulb as indicated by the white arrowheads. (d) Quantification of the number of glomeruli receiving M71 projections per half bulb in BACE1 +/+, BACE1 +/− and BACE1 −/− mice. Differences between BACE1 +/− and BACE1 +/+ and between BACE1 −/− and BACE1 +/+ mice are statistically significant. Immunostaining using an antibody against GFP in P2-IRES-GFP transgenic animals crossed to BACE1 +/+ mice (e), BACE1 +/− mice (f) or BACE1 −/− mice (g) revealed a disturbance of axon targeting of P2-expressing OSNs in the BACE1 mutants. Quantification of the number of glomeruli receiving P2 OSN axon projections per half bulb (h) revealed statistically significant differences between BACE1 +/− and BACE1 +/+; and BACE1 −/− and BACE1 +/+ mice. Immunostaining using an antibody against MOR28 revealed that the axons of MOR28-expressing OSNs converge to one specific glomerulus in each half bulb of the BACE1 mutants (i – k). Quantification of the number of glomeruli receiving MOR28-expressing OSN axon projections per half bulb (l) revealed no statistically significant difference between BACE1 +/− and BACE1 +/+, or BACE1 −/− and BACE1 +/+ mice.
