|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
|
Fig. 4. Expression directed by newly identified fly and mosquito enhancers. The
newly identified enhancers for vn (497 bp), sim (631 bp) and
A. gambiae sim (976 bp) were fused to lacZ reporter genes.
Embryos transgenic for these reporter constructs were analyzed by in situ
hybridization, as described in Fig.
1. All embryos are depicted with anterior to the left. (A,C,E)
Ventrolateral views of cellularizing embryos; (B,D,F) ventral views of
gastrulating embryos. The vn enhancer drives expression in the
ventral neurogenic ectoderm (A,B), similar to brk, vnd and
rho (compare with Fig.
2A,C,E). The enhancer is located in the first intron of
vn. The sim enhancer (C,D) drives expression in the
mesectoderm, the ventral-most line of cells of the neurogenic ectoderm. The
enhancer is located 5' of the sim gene. Weak and variable
staining is also detected in more ventral regions of early embryos (C),
possibly due to the loss of crucial Snail repressor sites. The Anopheles
sim enhancer (E,F) drives irregular expression in the mesectoderm,
similar to the pattern obtained with the Drosophila sim enhancer. The
enhancer is located 5' of a putative sim ortholog. The relative
arrangement and orientations of sequence motifs in the vn, sim and
Anopheles sim enhancers are depicted in G: Dorsal motifs (black
boxes), Su(H) motifs (red arrows), CA-Eboxes (CACATGT, dark-blue arrows) and
CTGWCCY sites (green arrows). Additionally, the location of a sub-optimal
Dorsal site (light gray box), a close relative to the CA-Ebox (CACATGG, light
blue arrow), and two close matches to the CTGWCCY motif (CTGNCCY, light green
arrows), are shown for the A. gambiae sim enhancer.
|
