transcripts are present in 0-1.5hr embryos where they are significantly more abundant than ph-p transcripts. Levels drop off sharply and rise again in 3-6hr embryos. Levels drop off again after the 9-12hr embryo stage and remain low for all subsequent stages tested. Probes specific for ph-d
were used for the analysis.
ph transcripts are observed in the germarium and in stage 1-10 egg chambers. In later stages, staining is confined to nurse cells and follicle cells and is not seen in the ooctye. A light diffuse staining is observed in unfertilized eggs and early embryos. During the blastoderm stage, staining is observed in three stripes in the anterior of the embryo that extend from about 80% to 50% egg length. During gastrulation, expression is ubiquitous but is more intense in the ectoderm. During germ band extension, expression is more intense in parts of each parasegment and in germ band retraction, staining is more intense in CNS precursors. ph transcripts are observed in eye-antennal, leg, wing, and haltere discs in third instar larvae. While staining is observed all over the discs, some regions stain more intensely. For example, in eye-antennal discs, regions that will give rise to the posterior part of the eye and the orbital region as well as the proximal part of the antenna on the lateral side stain more intensely. The haltere disc consistantly shows a gradient of expression. The probes used do not distinguish between ph-p
The putative ph-d
transcripts are 6.1kb and 6.4kb and are detected in embryonic RNA.