A set of transgenic insertion stocks derived by TE mobilization using the P-element construct P{GawB}. The P{GawB} construct carries a w+mW.hs mini-white visible marker and Scer\GAL4 driver/enhancer trap sequences. The GAL4-UAS system is a binary system using Scer\GAL4, a yeast transcription activator protein gene, and Scer\UAS, the DNA binding site for the GAL4 protein. The P{GawB} construct acts as an enhancer trap: expression of the GAL4 is sensitive to enhancers in the genomic region of an insertion. When paired with a construct or insertion carrying a reporter gene downstream of Scer\UAS, the reporter gene is driven by and reflects the expression of the GAL4.
neur, bib and fng reporter expression was observed during the formation of ball-and-socket joints in the leg. These drivers are expressed in different but overlapping cell populations in the developing joint. bib and neur are expressed in the deep region of the cavity, flanked by fng expression in cells projecting into the ridge and cells on the ventral side of the cavity. bib was expressed distal to neur, with an overlap of about two cells. Shortly after the onset of ball formation, bib-expressing cells are in contact with the ball cuticle. The expression of neur appears to overlap largely with bib-expressing cells and to extend dorsally to them. bib and neur expression domains are four to six cells wide along the anteroposterior axis. When the ball has fully grown, the apical surfaces of bib-expressing cells comes into contact with the ventral side of the ball, and then the apical surfaces further shifted distally, eventually contacting the newly formed lip. Consistently, the apices of the ventral portion of neur-expressing cells (co-expressing bib) relocate to the ventral side of the ball, and the apical surfaces of their dorsal subsets move with the edge of the extending socket, until covering the ventral part of the socket. Meanwhile, the dorsal fng-expressing cells expand their apical surfaces, and when the socket cuticle forms at the bottom of the cavity, they
Location 2L:9984631-9984632 refined by FlyBase alignment of dbGSS accession AG217886 to D. melanogaster arm Release_4 and heterochromatin Release_3.2b. Insertion orientation revised.