Phenotype Image Detail

Image

Caption

A and B: Coronal sections through the branchial arch region of E9.5 wild type (WT, A) and Aldh1a2^tm1Dll/Aldh1a2^tm1Ipc (Raldh2^neo/-, B) embryos (hematoxylin and eosin staining) show a marked hypoplasia of the putative third and fourth to sixth arches in the mutant, despite the presence of recognizable ectodermal clefts (arrowheads). b2 and b3, branchial arches; P2-P4, pharyngeal pouches. C and D: Intracardial China ink injection allows to visualize the third, fourth and sixth aortic arches (A3-A6) in E11.5 wild type embryos (C). In mutant embryos, the arterial flow passes through the third aortic arches (A3) and a single enlarged posterior arch ('A4-6'). AS, aortic sac. Injections performed at an earlier stage (E9.5, Insets) show delayed development of the third aortic arches in mutants. E and F: In situ hybridization (ISH) of E9.5 embryos with a Crabp1 probe, a marker for migratory neural crest cells (NCC), shows abnormal NCC patterning caudally to the second branchial arch (b2) in the mutant embryo (F). Instead of forming separate streams colonizing the third (b3) and fourth to sixth (b4-6) arches, cells are arranged in a single mass ('b3-6'), which is poorly connected with the hindbrain (arrowhead). G and H: Antineurofilament immunostaining of E11.5 embryos reveals an abnormal fusion of the developing 9th and 10th cranial nerves (N9/10) in the mutant (H). G5 and G7/8, trigeminal and facial-acoustic ganglia, respectively. I and J: ISH of E9.5 embryos with a Tbx1 probe shows reduced expression in the mutant posterior pharyngeal endoderm (J, arrowhead).

Copyright

This image is from Vermot J, Proc Natl Acad Sci U S A 2003 Feb 18;100(4):1763-8. Copyright 2003 National Academy of Sciences, U.S.A. J:81969

Associated Alleles

Symbol	Name
Aldh1a2^tm1Dll	aldehyde dehydrogenase family 1, subfamily A2; targeted mutation 1, Pascal Dolle
Aldh1a2^tm1Ipc	aldehyde dehydrogenase family 1, subfamily A2; targeted mutation 1, Pierre Chambon

Associated Genotypes

Allelic Composition	Genetic Background
Aldh1a2^tm1Dll/Aldh1a2^tm1Ipc	involves: CD-1