transcript is expressed in the proximal region of the wing disc, and the anterior compartment in leg discs; expression is absent from the wing pouch.
is expressed before and throughout salivary gland invagination during embryonic stages 11 and 12. At stage 13, it is no longer expressed in the salivary glands but is detected in salivary gland ducts.
transcripts are detected at all stages of development.
is expressed in all developmental stages tested. Expression is first observed at the syncytial blastoderm stage in the presumptive hindgut, head regions, and parasegment 2. Shortly after, stripes of expression are seen first in the even numbered parasegments and then in the odd numbered parasegments. By the extended germ band stage, 18w
is expressed in 15 transverse stripes with patches of expression corresponding to the 4 head segments and the hindgut as well. 18w
expression in the trunk region was shown to overlap the wg
stripes and spans the parasegmental boundary. At full germ band extension, the stripes begin to fade and expression is observed in segmentally repeated lateral clusters corresponding to the tracheal pits and the segmental grooves. Expression is accentuated in the cells surrounding the anterior and posterior spiracles. Transient expression in the CNS is also seen. Later, 18w
expression is observed in the wing and haltere disc primordia, the dorsal vessel, the antennal-maxillary sense organs, the clypeolabrum, the anterior and posterior spiracles, and in the anal plate.
transcripts are expressed in all stages of development tested. They are expressed in a complex pattern during embryogenesis. Expression is first observed just prior to cellular blastoderm formation in three stripes in the anterior portion of the embryo and a broader posterior domain. Subsequently, stripes are seen in the central region of the embryo. At late cellular blastoderm, secondary stripes appear leading to the transient expression of 18 stripes during early gastrulation and 20 stripes at stage 10. 18w
expression overlaps the wg
stripes and spans the parasegmental boundary. At maximum germ band extension, expression is observed along the ventral midline in small clusters of cells posterior to each stripe. Staining is also observed in salivary gland placodes, in tracheal pits, and in five areas in the presumptive head region. During germ band retraction, transcripts are less abundant and more restricted. They are observed in the developing tracheal system, the salivary gland anlagen, the anlagen for the anal plate, the posterior spiracles, the clypeolabrum, and in cells that participate in the formation of the dorsal vessel. In stage 15 and 16, 18w
expression is also observed in regions of the head, pharynx, stomach, and hindgut.