Picture from Herman MA (2001) Development "C. elegans POP-1/TCF functions in a canonical Wnt pathway that controls cell ...."

Figure 1. POP-1 is asymmetrically distributed at the T cell division. POP-1 expression in T.a and T.p. Whole-mount larvae 5-7 hours post-hatching, were stained with monoclonal anti-POP-1 antibodies and MH27 monoclonal antibodies, which outline hypodermal cells. The V cell (V) and T cell (T) daughters are indicated. (A) In wild-type animals, the level of POP-1 is higher in Vn.a than in the Vn.p, and also higher in T.a than in T.p. (B) In lin-17 animals, the levels of POP-1 are high in both T.a and T.p. (C) In lin-44 animals, the level of POP-1 is higher in Vn.a than in the Vn.p, but is higher in T.p than in T.a. (D) In pop-1 zygotic RNAi animals, POP-1 is often not detected in T.a and T.p. POP-1 was detected in the Vn.x cells in 26% (n=229) of pop-1 zygotic RNAi animals; arrowheads indicate POP-1-positive Vn.x nuclei in the lateral hypodermis of an adjacent pop-1 zygotic RNAi animal. Scale bars: 10 µm.

Picture from Siegfried KR et al. (2004) Genetics "The sys-1 and sys-3 genes cooperate with Wnt signaling to establish the ...."

Figure 6. Genetic and molecular models. (A and B) Two models of sys-1 and sys-3 in frizzled signaling. SYS-1 and SYS-3 do not control POP-1 asymmetry and therefore either function in parallel to WNT and MAPK signaling (A) or regulate POP-1 in the nucleus downstream of Wnt/MAPK regulation of POP-1 asymmetry (B). (C) SYS-1 may be a limiting coactivator of POP-1. POP-1 protein (solid circle) is less abundant in the nuclei of distal Z1/Z4 daughters compared to the proximal Z1/Z4 daughters. SYS-1 protein may be equally abundant in nuclei of all daughters, but present in limiting quantity. In the distal daughters the ratio of POP-1 to SYS-1 is about equal, and together these proteins activate distal genes. In the proximal daughters, POP-1 is more abundant than SYS-1 in the nucleus and less activator complex is made. On its own, POP-1 may repress distal genes and therefore outcompetes any SYS-1/ POP-1 activator complex made.

Picture from Mila D et al. (2015) Genetics "Asymmetric Wnt Pathway Signaling Facilitates Stem Cell-Like Divisions via the ...."

(A) FRK-1 is nuclear localized and asymmetric in ananterior-posterior manner in dividing seam cells within the V1-4 population(middle) similar to POP-1 (top), with higher levels in the anterior daughter. POP-1 asymmetry is lost in the absence of FRK-1, with both daughters containing low levels of POP-1 (bottom).

Picture from Herman MA (2001) Development "C. elegans POP-1/TCF functions in a canonical Wnt pathway that controls cell ...."

POP-1 is asymmetrically distributed at the T cell division. POP-1 expression in T.a and T.p. Whole-mount larvae 5-7 hours post-hatching, were stained with monoclonal anti-POP-1 antibodies and MH27 monoclonal antibodies, which outline hypodermal cells. The V cell (V) and T cell (T) daughters are indicated. (A) In wild-type animals, the level of POP-1 is higher in Vn.a than in the Vn.p, and also higher in T.a than in T.p. Scale bar: 10 um.

Picture from Lin R et al. (1998) Cell "POP-1 and anterior-posterior fate decisions in C. elegans embryos."

Figure 3. POP-1 in Postembryonic Development. (A and B) Immunofluorescence micrographs of the left and right sides of a young second stage (L2) larva stained for POP-1. The row of nuclei with alternating high levels (arrows) and low levels of POP-1 correspond to seam cells. POP-1 staining also is seen in the developing gonad (open arrowheads) and in left/right asymmetric migrating cells called Q neuroblasts (closed arrowheads). (C and D) High magnification view of the seam cell nuclei in an L1 larva; seam nuclei are one cell division earlier than the nuclei shown in (A). Larvae were stained simultaneously for POP-1 and for an adherens junction component to outline cell boundaries. Sister cells are indicated by double-headed arrows. Note the higher level of POP-1 in the nucleus of the anterior sister than in the posterior (arrow) sister.

Picture from Mila D et al. (2015) Genetics "Asymmetric Wnt Pathway Signaling Facilitates Stem Cell-Like Divisions via the ...."

Figure 6 FRK-1 nuclear localization parallels that of POP-1 in seam cellsnuclei postdivision. (A) FRK-1 is nuclear localized and asymmetric in ananterior-posterior manner in dividing seam cells within the V1-4 population(middle) similar to POP-1 (top), with higher levels in the anterior daughter. POP-1 asymmetry is lost in the absence of FRK-1, with both daughters containing low levels of POP-1 (bottom). (B) Quantification of FRK-1 and POP-1 asymmetry in seam cell daughters is similar in wild type compared to POP-1 in frk-1 (ok760) mutants (FITC signal in A is normalized to DAPI for quantitation). (C) WRM-1 is normally asymmetric in dividing seam cell nuclei (top), but becomes more symmetric in the absence of frk-1 (bottom). (D) Quantitation of WRM-1::YFP localization in the anterior and posterior daughter nuclei shows a significant loss of asymmetry immediately postdivision (*P , 0.05, with all other comparisonsP . 0.05.).

Picture from Uehara T et al. (2015) PLoS Genet "The Tumor Suppressor BCL7B Functions in the Wnt Signaling Pathway."

Fig. 5. BCL-7 is involved in the asymmetric localization of Wnt components in Caenorhabditis elegans. A-D: Nomarski (A, C) and GFP (B, D) images of wild type (A, B) and tm5268 (C, D) L2-stage hermaphrodites carrying a wrm-1::gfp reporter (osIs5) at pre-division states. Seam cells are traced with dotted ovals (A, C). E-H: Nomarski (E, G) and GFP (F, H) images showing the localization of WRM-1::GFP in two daughter cells of wildtype or tm5268 L2 hermaphrodites at post-divisions. The pairs of daughter cells are outlined with dotted ovals. I: Frequency of the localization patterns of WRM-1::GFP. The equal and unequal signs indicate the relative intensities of nuclear WRM-1::GFP between two daughter cells. J-M: Nomarski (J, L) and GFP (K, M) images showing the localization of GFP::POP-1 (qIs74) in two daughter cells of wild-type (J, K) or tm5268 (L, M) L1 hermaphrodites in post-division states. The pairs of daughter cells are outlined with dotted ovals. Asterisks indicate nuclei with stronger expression of GFP. N: The frequency of the localization patterns of GFP::POP-1. The equal and unequal signs indicate the relative intensities of nuclear GFP::POP-1 between two daughter cells. O-R: Nomarski (O, Q) and GFP (P, R) images showing the localization of GFP::POP-1 (qIs74) in SGPs of wild-type (O, P) or tm5268 (Q, R) early L1 hermaphrodites. SGPs are outlined with dotted ovals. S: The frequency of the localization patterns of GFP::POP-1. The equal and unequal signs indicate the relative intensities of nuclear GFP::POP-1 between two daughter cells. Anterior is oriented toward the left, and ventral is oriented toward the bottom. T: Percentages of worms with the aberrant POP-1 asymmetry in both Z1 and Z4 cells, either Z1 or Z4 cells, and no cells in one worm between wild type and bcl-7 mutant worms. Numbers of examined samples were more than 30 for all analyses. Scale bar = 25 um.

Picture from Uehara T et al. (2015) PLoS Genet "The Tumor Suppressor BCL7B Functions in the Wnt Signaling Pathway."

Fig. 5. BCL-7 is involved in the asymmetric localization of Wnt components in Caenorhabditis elegans. A-D: Nomarski (A, C) and GFP (B, D) images of wild type (A, B) and tm5268 (C, D) L2-stage hermaphrodites carrying a wrm-1::gfp reporter (osIs5) at pre-division states. Seam cells are traced with dotted ovals (A, C). E-H: Nomarski (E, G) and GFP (F, H) images showing the localization of WRM-1::GFP in two daughter cells of wildtype or tm5268 L2 hermaphrodites at post-divisions. The pairs of daughter cells are outlined with dotted ovals. I: Frequency of the localization patterns of WRM-1::GFP. The equal and unequal signs indicate the relative intensities of nuclear WRM-1::GFP between two daughter cells. J-M: Nomarski (J, L) and GFP (K, M) images showing the localization of GFP::POP-1 (qIs74) in two daughter cells of wild-type (J, K) or tm5268 (L, M) L1 hermaphrodites in post-division states. The pairs of daughter cells are outlined with dotted ovals. Asterisks indicate nuclei with stronger expression of GFP. N: The frequency of the localization patterns of GFP::POP-1. The equal and unequal signs indicate the relative intensities of nuclear GFP::POP-1 between two daughter cells. O-R: Nomarski (O, Q) and GFP (P, R) images showing the localization of GFP::POP-1 (qIs74) in SGPs of wild-type (O, P) or tm5268 (Q, R) early L1 hermaphrodites. SGPs are outlined with dotted ovals. S: The frequency of the localization patterns of GFP::POP-1. The equal and unequal signs indicate the relative intensities of nuclear GFP::POP-1 between two daughter cells. Anterior is oriented toward the left, and ventral is oriented toward the bottom. T: Percentages of worms with the aberrant POP-1 asymmetry in both Z1 and Z4 cells, either Z1 or Z4 cells, and no cells in one worm between wild type and bcl-7 mutant worms. Numbers of examined samples were more than 30 for all analyses. Scale bar = 25 um.

Picture from Siegfried KR et al. (2004) Genetics "The sys-1 and sys-3 genes cooperate with Wnt signaling to establish the ...."

Figure 2. GFP::POP-1 localization in the Z1/Z4 daughters. All panels show L1 larvae expressing GFP::POP-1(d1-5) [animals expressing GFP::POP-1(FL) show similar localization]. The gonad is indicated by the dashed circle. Nuclei of sister cells are indicated by brackets. Images alongside each other are of the same animal: DIC on the left and fluorescence on the right. Bars, 5 um. (A and B) The T daughters are posterior; (C-J) anterior is to the left. (A and B) In the V and T cell daughters, GFP::POP-1 shows more GFP in nuclei of anterior sister cells than in posterior sister cells. (C-F) GFP:: POP-1 is higher in nuclei of the proximal Z1/Z4 daughters than in the distal daughters. GFP-positive puncta are present in the nuclei of the proximal daughters (D, arrowheads). (G-J) lit-1(RNAi) or wrm-1(RNAi) results in similar nuclear levels of GFP::POP-1 in Z1/Z4 daughters. GFP-positive puncta are often seen in both Z1/Z4 daughters (H, arrowheads). The Z1 daughters are shown.

Picture from Siegfried KR et al. (2002) Development "POP-1 controls axis formation during early gonadogenesis in C. ...."

Figure 3. Defects in pop-1(Sys) hermaphrodite gonad. (A-C) Animals carrying lag-2::GFP. Animals in A and C carry qIs56[lag-2::GFP], animal in B carries qIs19[lag-2::GFP]. Both transgenes have similar GFP expression in the DTC, but qIs56 has brighter GFP expression in the ventral nerve cord than qIs19. (A) Wild-type L3, SPh and one gonadal arm are shown. The DTC caps the end of the elongating arm and expresses lag-2::GFP brightly (arrow). Somatic gonadal cells within the SPh (black arrowheads) cluster centrally. (B,C) pop-1(q645) and pop-1(RNAi) animals have no gonadal elongation and no bright lag-2::GFP expression. Somatic gonadal cells are arranged around the gonadal periphery (black arrowheads). (D-F) Animals expressing cdh-3::GFP. (D) Wild-type L3. The AC marker cdh-3::GFP is expressed in a single cell (white arrowhead). (E,F) pop-1(q645) and pop-1(RNAi) L3 animals can have multiple ACs (white arrowheads).