PT  - JOURNAL ARTICLE
AU  - Sun, Y H
AU  - Tsai, C J
AU  - Green, M M
AU  - Chao, J L
AU  - Yu, C T
AU  - Jaw, T J
AU  - Yeh, J Y
AU  - Bolshakov, V N
TI  - White as a reporter gene to detect transcriptional silencers specifying position-specific gene expression during Drosophila melanogaster eye development.
DP  - 1995 Nov 01
TA  - Genetics
PG  - 1075--1086
VI  - 141
IP  - 3
4099  - http://www.genetics.org/content/141/3/1075.short
4100  - http://www.genetics.org/content/141/3/1075.full
SO  - Genetics1995 Nov 01; 141
AB  - The white+ gene was used as a reporter to detect transcriptional silencer activity in the Drosophila genome. Changes in the spatial expression pattern of white were scored in the adult eye as nonuniform patterns of pigmentation. Thirty-six independent P[lacW] transposant lines were collected. These represent 12 distinct pigmentation patterns and probably 21 loci. The spatial pigmentation pattern is due to cis-acting suppression of white+ expression, and the suppression probably depends on cell position rather than cell type. The mechanism of suppression differs from inactivation by heterochromatin. In addition, activation of lacZ in P[lacW] occurs also in specific patterns in imaginal discs and embryos in many of the lines. The expression patterns of white+ and lacZ may reflect the activity of regulatory elements belonging to an endogenous gene near each P[lacW] insertion site. We speculate that these putative POSE (position-specific expression) genes may have a role in pattern formation of the eye as well as other imaginal structures. Three of the loci identified are optomotor-blind, engrailed and invected. teashirt is also implicated as a candidate gene. We propose that this "silencer trap"' may be an efficient way of identifying genes involved in imaginal pattern formation.