imaginal disk

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imaginal disk

[ə′maj·ən·əl ‚disk]
(invertebrate zoology)
Any of the thickened areas within the sac of the body wall in holometabolous insects which give rise to specific organs in the adult.
References in periodicals archive ?
Basler, "A screen for genes expressed in Drosophila imaginal discs," International Journal of Developmental Biology, vol.
Tabata, "Hedgehog creates a gradient of DPP activity in Drosophila wing imaginal discs," Molecular Cell, vol.
Using these two protein traps, we mapped the binding sites of both transcription factors and identified their in vivo target genes in the embryo and specific imaginal discs [32].
Light staining was found in the larval lymph glands [ILLUSTRATION FOR FIGURE 3 OMITTED] and eye and antenna imaginal discs of some active larvae [ILLUSTRATION FOR FIGURE 4 OMITTED!.
In inactive late third-instar larvae, which are entering the quiescent stage just preceding pupariation, staining of the eye and antenna imaginal discs [ILLUSTRATION FOR FIGURE 5A OMITTED], lymph glands [ILLUSTRATION FOR FIGURE 5B AND C OMITTED], and cellular epidermis [ILLUSTRATION FOR FIGURE 5D AND E OMITTED!
The anterior region housing the imaginal discs had areas of foamy-appearing tissue, rich in droplets, probably of lipid, surrounded by diffuse stain.
At staining pH levels of 7.2 and 6.0, sites of activity were the lymph glands, cellular epidermis, and eye-antenna imaginal discs of the larva and the thoracic nephrocytes and fat body of the adult.
If staging errors are made - for example, if an active third-instar larva is used as a control animal but a slightly older inactive transformed larva is assayed for lacZ fusion-gene activity - the pronounced endogenous activity in the eye and antenna imaginal discs, lymph glands, and cellular epidermis could be construed as ectopic expression of the lacZ fusion-gene product.
The appearance of endogenous [Beta]-galactosidase activity in the ventral ganglion, eye and antenna imaginal discs, lymph glands, and cellular epidermis in late third-instar larvae just prior to pupariation coincides with a dramatic increase in ecdysteroid titer 10 h before puparium formation (Bainbridge and Bownes, 1988).
4B) reveals that cells are arranged most densely in the apical organ, the stomach, the esophageal ciliary ridges, the imaginal discs, and within the primary ciliated band near the pilidial axils, the recesses between the larval lobes and lappets, described by Bird et al.
The order of emergence of imaginal discs corresponded to that observed in other pilidia (cephalic discs first, trunk discs next, and cerebral organ discs last).