|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
|
Fig. 5. Prethalamus but not telencephalon is rescued in
Six3-/-;Wnt1-/- embryos.
Foxg1 is expressed in the telencephalon of wild-type (A) and
Wnt1-/- (A') mouse brains at E10.5. No
telencephalic expression of Foxg1 was observed in
Six3-/- (A'') or
Six3-/-;Wnt1-/- brains (A''').
Emx1 is expressed in the dorsal telencephalon of wild-type (arrow,
B) and Wnt1-/- (arrow, B') brains.
Tbr1 is expressed in the telencephalon (arrow) and eminentia thalami
(arrowhead) of wild-type (C) and Wnt1-/-
(C') brains. No telencephalic expression of Emx1 and
Tbr1 was observed in the Six3-/-
(B'',C'') and
Six3-/-;Wnt1-/-
(B''',C''') brains. Irx1 is expressed in the
alar plate of the thalamus (arrow) of wild-type (D),
Wnt1-/- (D') and Six3-null
(D'') brains at E10.5. In the Six3-null brain (D''),
Irx1 expression expands anteriorly; this ectopic expansion was
rescued in the Six3-/-;Wnt1-/- brain
(D'''). Similar results were obtained with Tcf4, a gene
that is expressed in the alar plate of the pretectum and in the thalamus of
wild-type (E), Wnt1-/- (E'),
Six3-/- (E'') and
Six3-/-;Wnt1-/- embryos (E'''). The
prethalamus (arrow), as indicated by Fezf1 expression in the
wild-type (F) and Wnt1-/- (F') brain,
is extremely reduced in the Six3-null brain (F'');
however, it appears normal in the
Six3-/-;Wnt1-/- brain (F'''). A
model for the Six3-/-;Wnt1-/- brain at this
stage is shown (G'''). In the Wnt1-/- brain
(G'), the mesencephalon is smaller than in the wild-type brain
(G). The prospective thalamus is the most anterior structure in the
Six3-null brain (G''), and the prethalamus remains in the
Six3-/-;Wnt1-/- brain (G''') at this
stage. The basal plate is indicated in blue. Lines delimit the prospective
regions. Anterior is to the right. H, hindbrain; HY, hypothalamus; M,
mesencephalon; PT, prethalamus; PTC, pretectum; T, thalamus; TEL,
telencephalon.
|
