Picture from Crittenden SL et al. (1994) Development "GLP-1 is localized to the mitotic region of the C. elegans germ line."

Figure 5. Localization of GLP-1 to the distal end of the germ line. Confocal sections of a wild-type hermaphrodite gonad co-stained with anti-LNG(A,C) and anti-DNA (B,D). The distal end is at the upper left (*); the proximal end is at the lower left (**). Scale bars, 20 µm. Oocytes aremarked by arrowheads. (A) Surface focal plane. Intense membrane-associated GLP-1 is found in the most distal germ cells (a'). More proximally, the intensity of membrane-associated GLP-1 staining decreases rapidly. GLP-1 is undetectable in maturing germ cells and oocytes. (B) Surface focal plane. DNA in nuclei is visible throughout the germ line. (C) Middle focal plane. Membrane-associated GLP-1 is intense distally and decreases proximally. Internal, punctate GLP-1 extends further proximally before it decreases and becomes undetectable. (D) Middle focal plane. DNA is visible in nuclei throughout germ line.

Picture from Crittenden SL et al. (1994) Development "GLP-1 is localized to the mitotic region of the C. elegans germ line."

Figure 4. Subcellular distribution of GLP-1. All panels show hermaphrodite gonads. (A) Surface focal plane of distal region (a', Fig. 5A) stained with -LNG. GLP-1 outlines each germ cell. (B) Surfacefocal plane of distal region stained with -ANK. Distribution is the same as that observed with -LNG;note lack of nuclear GLP-1. (C) Middle focal plane of distal region (b', Fig. 5C) stained with anti-LNG. GLP-1 is found in an internal, punctate pattern. (E) Surface focal plane of distal gonad homozygous for the nonsense mutant glp- 1(q175) (Kodoyianni et al., 1992; Fig. 1). The glp-1(q175) single mutant has a Glp-1 null phenotype with no germline mitosis; however, as a triple mutant with gld-1(q268) and fog-1(q180), some germline mitosis occurs (T. Schedl, personal communication). The gonad shown here is a fog-1(q180)gld- 1(q268); unc-32 (e189)glp-1(q175) homozygote stained with anti-LNG. GLP-1 is not detected, confirming the specificity of the antibody. Scale bars, 20 μm.

Picture from Crittenden SL et al. (1994) Development "GLP-1 is localized to the mitotic region of the C. elegans germ line."

Figure 8. In situ hybridization of glp-1. Distal (*) and proximal (**) ends are marked. (A) Dissected adult hermaphrodite gonad hybridized with glp-1 anti-sense RNA probe. glp-1 mRNA is uniformly distributed throughout the germ line, including oocytes (arrowheads). No glp-1 mRNA is detected in sperm (arrow). (B) Dissected adult hermaphrodite gonad hybridized with glp-1 sense RNA probe. No signal is detected. (C) Dissected adult male gonad hybridized with glp-1 anti-sense RNA probe. glp-1 mRNA is most abundant distally, but decreases more proximally. No glp-1 mRNA is detected in mature sperm. D. Dissected adult male gonad hybridized with glp-1 sense RNA probe. No signal is detected. Scale bar, 10 µm.

Picture from Henderson ST et al. (1997) Mol Biol Cell "Functional domains of LAG-2, a putative signaling ligand for LIN-12 and GLP-1 ...."

Figure 3. LAG-2(extra 1-286) induces germ line tumors and ectopic GLP-1. A composite of confocal images of dissected adult hermaphrodite germ lines is shown; distal is left, stained with antibodies to GLP-1 (Crittenden et al., 1994). (A) Wild-type germ line. GLP-1 is associatedwith membranes at distal end of the germ line and is absent proximally. Inset, arrow indicates faint staining at the distal tip of the germ line.(B) +;Ex LAG-2(extra 1-286) germ line, raised at 25C. GLP-1 is present both distally and proximally. Inset, open arrow indicates intenseGLP-1 staining associated with the distal tip of the germ line; closed arrows indicate intense punctate staining within the germ line. Scale bar,20 um.

Picture from Henderson ST et al. (1994) Development "lag-2 may encode a signaling ligand for the GLP-1 and LIN-12 receptors of C. ...."

Figure 6. Distribution of LAG-2::β-gal and GLP-1 in adult germline.(A) Schematic representation of distal region of adult germline, showing DTC on left. DTC nucleus shown as open circle, mitotic germ nuclei shown as black circles. Thin lines represent cell membranes, mitotic germ line is a syncytium. Scale bar, 20 µm. (B-D) Confocal images of dissected germlines that have been double stained with both anti-β-galactosidase (red) and anti-GLP-1 (green)antibodies. (B) GLP-1 is present in germline membranes. See Crittenden et al. (accompanying paper) to see definitively that the DTC does not contain GLP-1. (C) The LAG-2::β-gal fusion protein is present in the DTC and also near the center of the germline. (D) Simultaneous detection of anti-GLP-1 and anti-β-gal using merged fluorescein and rhodamine confocal image. Note co-localization of GLP-1 staining and β-gal staining within membranes of the germline.