|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
|
Fig. 5. Mechanism of Wnt7b action in mouse lung development. (A) ISH
showing loss of canonical Wnt targets in mesenchyme and endoderm of
Wnt7b mutant lungs. Dotted lines encircle epithelium. Arrowheads
point to periendodermal mesenchyme. (B) E12.5 whole-mount ISH of
Axin2 and Lef1 in cultured wild-type lungs. Wnt signaling is
decreased with the addition of Dkk1 (left) and enhanced by lithium (right)
when compared with control cultures (middle). In lithium-treated lungs,
mesenchymal staining of the canonical targets has expanded. (C)
Axin2 expression in mesenchyme cultured alone and in mesenchyme
recombined with epithelium, showing that mesenchymal Axin2 expression
requires endoderm induction. (D) Lithium rescues Lef1
expression in E12.5 mutant lungs when compared with Wnt7b mutant
lungs cultured without lithium. (E) Epithelial Wnt7b activates a
canonical pathway in neighboring mesenchyme. (F) Bmp4 and
Id2 expression are coincident on serial sections of E14.5 wild-type
lung (left). Expression of epithelial Bmp4 and Id2 are
decreased in mutant lungs (middle and right). (G) Lithium induces
ectopic Id2 expression in cultured E12.5 wild-type lungs. (H)
Wnt7b induces Bmp4 and Id2 production in endoderm tip cells. (I) Wnt7b
coordinately activates autocrine and paracrine signaling cascades to increase
cell replication.
|
