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. 2020 Sep 8;29(18):3081–3093. doi: 10.1093/hmg/ddaa199

Figure 1.

Figure 1

An overview of trigeminal nerve (CN V) dysmorphology and RA-dependent hindbrain patterning in a series of 22q11.2-related mutations. A total of 14 whole E10.5 embryos were imaged confocally. Eight: 1 WT, 4 Tbx1+/−, 2 Ranbp1+/−: and 1 LgDel+/−:Raldh2+/− had CN V gross morphology that resembled that in WT identified previously in more extensive conventionally imaged samples (6–8; Supplementary Material, Fig. S1), and six: 3 LgDel+/− and 3 Ranbp1−/− had CN V gross morphology similar to that previously identified for LgDel+/− (6–8; Supplementary Material, Fig. S1). (A1) WT E10.5 embryo. CN V (box) and the trigeminal ganglion (CNgV; oval) are anterior in this lateral view. (A2) In the E9.5 WT hindbrain, Cyp26b1, detected by in situ hybridization, is seen in r5 and r6, but not r2, r3 or r4. (A3) A higher magnification confocal image of WT CNgV/CN V and its peripheral branches: ophthalmic (op), maxillary (mx) and mandibular (md); brackets indicate the regions of the mx and md branches shown in (4) and (5). (A4) The WT mx branch. Arrows (a) indicate parallel proximal axon fascicles; arrowheads (b) indicate limited terminaldefasciculation. (a) digitally enlarged images of region indicated by arrows showing segregated parallel fascicles, and (b) the region indicated by the arrowheads showing WT axon terminations. (A5) Axons of a deep branch of the md division of CN V (arrow) enter Ba1B mesenchyme. A superficial branch terminates in an array of smaller fascicles (asterisk). Upper inset: terminal defasciculation of the superficial branch. Lower inset: fasciculation in the proximal md branch. (B1) An E10.5 LgDel+/− embryo. (B2) LgDel+/− Cyp26b1 in situ hybridization at E9.5 (B3) CNgV and peripheral branches of CN V. (B4) Digitally enlarged views of mx (4) and md (5) branches. Arrows in (4) indicate smaller fascicles that appear less uniform than WT parallel arrays (A4, a). Arrowheads indicate LgDel+/− terminal fascicles, which appear less dense and organized than WT (A4, b). (B5) The md branch is diminished, terminal defasciculation is impoverished (asterisk, upper inset) and proximal fascicles are disordered (lower inset). (C1–5) Tbx1+/− E10.5 CN V, E9.5 hindbrain patterning, mx and md axon organization does not differ noticeably from WT. (D1) Ranbp1−/− E10.5 embryo. (D2) E9.5 Ranbp1−/− hindbrain patterning. (D3) Ranbp1−/− CNgV and CN V branches. (D4) Ranbp1−/− mx fasciculation and termination appears similar or potentially more severe than that in LgDel+/− (A4, a, b). (D5) Ranbp1−/− md fasciculation and termination appears similarly compromised as that in LgDel+/−. (E1–5; F1–5) Ranbp1+/− and LgDel+/−:Raldh2+/− E10.5 CN V, E9.5 hindbrain patterning, mx and md axon organization does not differ noticeably from WT.