Figure 5. Expression of
pst-1 and
pst-2. (A) Schematic of expression constructs. The 20kb genomic environs of
pst-1 and
pst-2 (Wormbase, WB203) are shown. A yellow fluorescent protein (YFP) with a nuclear localization signal (NLS) under control of an intercistronic region directing SL2-splicing (red) is inserted after the stop codon for
pst-1a in fosmid WRM063bF12. A cyan fluorescent protein (CFP) with NLS is inserted after the stop codon for
pst-2 in fosmid WRM0612bH01. Black boxes denote coding exons of
pst-1 and
pst-2, gray boxes of the preceding genes within the operons (indicated as green bars), and white boxes denote coding exons of surrounding genes. Predicted start codons and direction of transcription are indicated by a rectangular arrow and stop codons by an asterisk. Straight arrows indicate the direction of transcription of partially shown genes. Approximate extent of the fosmid clones in kilobases (kb) is indicated on the left and right, respectively. Gene names are as shown. SL2, splice leader 2; CEOP, C. elegans operon. (B) Expression of the
pst-1 reporter at different developmental stages as shown. sc, seam cells; DIC, differential interference contrast; L1, first larval stage; phgc, pharyngeal gland cells. (C) Expression of the
pst-2 reporter at different developmental stages as indicated. Note faint expression in the hypodermis (hypodermal ridge). (D) Expression of
pst-1 (left panel) and
pst-2 (middle panel) appears mutually exclusive during the L2 larval stage (right panel). in, intestine; L2, second larval stage. Magnification is 400x in all panels except for the adult in B, which is 160x.