Article Figures & Data
Figures
- Figure 1.
Gene Enhancer Detectors and Gene Traps Used in the Past 10 Years.
Promoter traps require endogenous promoters (P) ([A] and [F]). Enhancer detectors capitalize on the presence of nearby genomic enhancers (E)
([B], [G], and [I] to [K]). Gene traps contain splice acceptor (SA) sites to produce fusions to the reporter gene ([C] to [E] and [H]).
(A) The Mu bacteriophage construct first used in E. coli. lacZ, lacY, and lacA form the bacterial lac operon.
(B) The first P-element enhancer detector used in Drosophila.
(C) By providing an SA site at the 5′ end of lacZ, retroviral insertions may produce fusion proteins.
(D) Similar to (C), but the fusion protein (βgeo) consists of the endogenous protein fused to both β-galactosidase and neomycin.
(E) The advantages of ROSAβgal (C) and ROSAβgeo (D) are combined into one vector.
(F) A construct used in C. elegans as a promoter trap for genomic fragments inserted into a transformation vector.
(G) Enhancer detector used in Arabidopsis.
(H) Gene trap used in Arabidopsis.
(I) Second-generation enhancer detector used in Drosophila.
(J) Similar to P-lArB (I).
(K) Commonly used enhancer detector in Drosophila.
Adh, alcohol dehydrogenase gene, which can be used as a positive and negative selectable marker; AmpR, ampicillin resistance; bpA, poly(A) addition site; GUS, β-glucuronidase; hsp, heat shock protein gene poly(A) addition site; hsp-w, white gene of Drosophila used to identify transformants; IRES, internal ribosomal entry site; KanR, kanamycin resistance; LTR, long terminal repeat of retrovirus; mini-w+, a white gene of Drosophila; neo, neomycin resistance gene; ORI, original of replication of E. coli; pBS, Bluescript vector; PGK, a consititutive promoter expressed in all cells; puro, puromycine resistance gene; rol-6, a dominant marker to identify transformants; rosy, eye color marker to identify transformants; SD, splice donor site; TRS, translation initiation site; unc53 3′end, a poly(A) addition site.
- Figure 2.
Other P-Element Vectors in Drosophila.
(A) The GAL4–UAS system relies on an enhancer detector that drives GAL4 expression in specific cells. The GAL4 protein then binds to UAS sites on a separate P element to activate another gene, such as the reporter gene lacZ. SV40, poly(A) addition site from SV40.
(B) Because of the presence of Su(Hw) sites in this P element (see text), the mutagenesis efficiency is double that of most P elements. yellow+ is body color marker.
(C) A bipartite system can be used to direct misexpression of endogenous genes (see text). The first P element drives GAL4 expression in specific cells. GAL4 in turn activates a hybrid UAS-containing promoter on the second P element. The UAS-containing promoter faces outward and may lead to transcripts that include adjacent genes in the genome.
Abbreviations are as given in the legend to Figure 1.
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- INTRODUCTION
- HISTORY AND PRINCIPLES
- BEYOND THE FRUIT FLY
- GENERATION AND USE OF CELL-SPECIFIC AND TISSUE-SPECIFIC MARKERS IN DROSOPHILA
- ENHANCER DETECTORS AS MUTAGENS
- MANIPULATING GENE EXPRESSION, CELL VIABILITY, AND CELL FUNCTION
- ENHANCER SUPPRESSORS
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