|
|
|
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
|
Fig. 1. Morphogenesis of the Drosophila pupal retina and the role of
cell adhesion. (A-F) Time course of retinal development. Apical
cell profiles were visualized with anti-Armadillo to highlight adherens
junctions. Anterior is to the right; times refers to hours after puparium
formation (APF). Unpatterned arrays of IPCs (A,B) sort to single file (C); IPC
number continues to decrease as patterning tightens (D) until the final
pattern is achieved (E,F). B and F are schematics of the central ommatidium
from A and E, respectively; cone cells (c, blue shading), primary pigment
cells (1°, brown), IPCs (red), 2° (red), 3° (pink) and bristles
(yellow) are indicated. Arrows in A,C,D,E point to IPC:IPC adherens junctions.
(G,H) 26 hours APF retina stained with anti-Rst (G) and
anti-DE-cadherin (H). Arrows point to the IPC:IPC junctions, where DE-cadherin
is expressed and Rst is absent. (I,J) 31 hours APF rst
mutant retinas; magnification is reduced to show additional ommatidia. Green
arrows point to IPC:IPC junctions that failed to clear (compare with wild
type, D). This defect correlated with the failure in mutant IPCs to sort out
into single-cell rows, as observed in mutants for the hypomorphic allele
rst3, which is subject to position effect variegation (I).
Red arrows in I point to rst3 regions where IPCs have
sorted out into single layers and have also cleared out their junctions; these
are likely to contain normal levels of Rst protein. (K-P) Scanning
electron micrographs of adult eyes (genotypes as listed) taken at 180x
(K,M,O) and 800x (L,N,P). K and L show a wild-type adult eye; a single
ommatidium is indicated with an asterisk. Note the straight ommatidial rows,
highlighted by a line drawn between ommatidia. The aberrant ommatidial packing
observed in an rst3 eye (M,N) is rescued by removing a
single functional copy of shg (O,P).
|
