Picture from Lin R et al. (1995) Cell "pop-1 encodes an HMG box protein required for the specification of a mesoderm ...."

Figure 7. Localization of POP-1 Protein.Fluorescence micrographs of a wild-type adult gonad (a and b) and early embryos (c-h) stained with either diamidophenylindole (DAPI) to visualize nuclei (left column) or POP-l antisera (right column). Embryos are oriented as shown in Figure 1.(a and b) Low magnification pictures of an adult gonad. The gonad consists of a syncytium of nuclei joined by a common cytoplasm and of individual maturing oocytes (lower right in panels). (c-h) High magnification pictures of Z-cell- (c and d), 4-cell- (e and f), and 9-cell-stage embryos (g and h).(g and h) An example of an embryo with different staining intensities in sister blastomeres. Arrows point to the nuclei of the sister blastomeres MS (closed) and E (open). Arrowheads point to the nuclei of the sister blastomeres C (closed) and P3 (open). The gonad and all embryos shown were stained with the 94I antiserum.

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

Figure 2. POP-1 Asymmetry in Early Wild-Type Embryos. Immunofluorescence micrographs of embryos stained for POP-1 (left column) or DAPI to visualize nuclei (right column). Embryos are oriented with anterior to the left. Sister cells are indicated by double-headed arrows.(A-D) Two focal planes of the same 12 cell-stage embryo showing three of the four pairs of ABxxa/ABxxp sisters; these sisters are born in an a/p division. Note that the anterior sister has a higher level of staining in all cases.(E and F) A 28 cell-stage embryo showing the two pairs of MS granddaughters; these are born in an a/p division (MSaa/MSap, MSpa/MSpp). Note the several prophase-stage nuclei (visible in F) that do not show POP-1 staining.(G and H) An approximately 100 cell-stage embryo showing the two pairs of E granddaughters; these are born from a transverse (left/right) division.(I and J) An approximately 200 cell-stage embryo showing the four pairs of E great-granddaughters; these are born from an a/p division.

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 Lin X et al. (2003) Curr Biol "C. elegans PAT-6/actopaxin plays a critical role in the assembly of integrin ...."

PAT-3 in wild-type 530 min embryos. Arrows indicate body wall muscle attachments.

Picture from Lin X et al. (2003) Curr Biol "C. elegans PAT-6/actopaxin plays a critical role in the assembly of integrin ...."

Figure 2. The pat-6 Gene Encodes the C. elegans Actopaxin Ortholog (A) Molecular cloning of pat-6 (see Results for details). (B) Immunoblot of whole-worm protein extracts prepared from the wild-type N2 strain (lane 1) or a pat-6(st561) mutant strain that is rescued by a pat-6::gfp transgene (lane 2). The blot was probed with anti-PAT-6/actopaxin. (C) PAT-6::GFP expressed by a rescued 430 min postfertilization pat-6(st561) embryo is localized to body wall muscle attachments (arrows). (D) Same embryo as in (C) immunostained with anti-PAT-6/actopaxin and MH27. As expected, muscle attachments stain with anti- PAT-6 (arrows). (E) Merge of (C) and (D), yellow regions show colocalization of the PAT-6::GFP and anti- PAT-6/actopaxin signals. (F) A nonrescued pat-6(st561) embryo at the same developmental stage has no GFP signal. (G) Same embryo as in (F) immunostained with anti-PAT-6/actopaxin and MH27. No PAT-6/actopaxin is detected in the region containing a dorsal muscle quadrant (arrows). Hypodermal cell junctions (arrowheads) and hypodermal cell junction remnants (labeled 'j') are stained by antibody MH27. (H) Merge of (F) and (G). Scale bar, 5 um.

Picture from Lin X et al. (2003) Curr Biol "C. elegans PAT-6/actopaxin plays a critical role in the assembly of integrin ...."

Figure 4. Epistasis Analysis of Muscle Attachment Assembly(A) Localization of UNC-52/perlecan, PAT-3/β-integrin, UNC-112, PAT-4/ILK, DEB-1/vinculin, and UNC-89 in wild-type (1-6) and pat-6(st561) (1'-6') in 530 min embryos. Arrows in all panels except for 6' indicate body wall muscle attachments. Arrows in 6' indicate clumps of UNC-89 protein located in the cytoplasm of body wall muscle cells. All proteins visualized by antibody staining except for UNC-112, which was visualized using a functional unc-112::gfp transgene.(B) Localization of PAT-6/actopaxin in wild-type, unc-52(st549), pat-3(st552), unc-112(gk1), pat-4(st551), and deb-1(st555) embryos (1-6). Arrows indicate regions of anti-PAT-6/actopaxin staining. PAT-6/actopaxin is properly recruited to muscle attachments in the wild-type (1) and deb-1 (6) embryos, but not in the unc-52(st549), pat-3(st552), unc-112(gk1), or pat-4(st551) embryos (2-5). The embryos were also stained with monoclonal antibody MH27 to hypodermal cell junctions, which appear as a grid-like pattern and are indicated by arrowheads in panel 5. Scale bar (A1), 5 μm.

Picture from Lin X et al. (2003) Curr Biol "C. elegans PAT-6/actopaxin plays a critical role in the assembly of integrin ...."

Figure 3. PAT-6::GFP Colocalizes with PAT-3/Integrin and PAT-4/ILK in Muscle Attachments (A-C) pat-6 embryo rescued by PAT-6::GFP and stained with the anti-PAT-3/integrin antibody MH25. (A) GFP channel, (B) anti-PAT-3/integrin channel, (C) merge. PAT-6::GFP and PAT-3/integrin colocalize (C, yellow regions) in embryonic muscle attachments (arrows). (D-F) pat-6 embryo rescued by PAT-6::GFP and stained with the anti-PAT-4/ILK. (D) GFP, (E) anti-PAT-4/ILK, (F) merge. PAT-6::GFP and PAT-4/ILK colocalize (E, yellow regions) in embryonic muscle attachments (arrows). (G) PAT-6::GFP is located in adult body wall muscle attachments. Dense bodies (arrows), M lines (arrowheads), and muscle-muscle adhesion plaques (brackets) are indicated. (H-J) Body wall muscle attachments of an adult that is coexpressing PAT-6::CFP and PAT-3::YFP. (H) CFP channel, (I) YFP channel, (J) merge. White areas in (J) show extensive colocalization of PAT-6::CFP and PAT-3::YFP in muscle attachments. All scale bars, 5 um.

Picture from Lin X et al. (2003) Curr Biol "C. elegans PAT-6/actopaxin plays a critical role in the assembly of integrin ...."

(C) PAT-6::GFP expressed by a rescued 430 min postfertilization pat-6(st561) embryo is localized to body wall muscle attachments (arrows). (D) Same embryo as in (C) immunostained with anti-PAT-6/actopaxin and MH27. As expected, muscle attachments stain with anti-PAT-6 (arrows). (E) Merge of (C) and (D), yellow regions show colocalization of the PAT-6::GFP and anti- PAT-6/actopaxin signals. (F) A nonrescued pat-6(st561) embryo at the same developmental stage has no GFP signal. (G) Same embryo as in (F) immunostained with anti-PAT-6/actopaxin and MH27. No PAT-6/actopaxin is detected in the region containing a dorsal muscle quadrant (arrows). Hypodermal cell junctions (arrowheads) and hypodermal cell junction remnants (labeled 'j') are stained by antibody MH27. (H) Merge of (F) and (G). Scale bar, 5 um.

Picture from Lin SY et al. (2003) Dev Cell "The C elegans hunchback homolog, hbl-1, controls temporal patterning and is a ...."

Figure 3. Postembryonic Expression Pattern of HBL-1/GFP in Wild-Type and let-7 Animals. (A) An early L1 BW1932 animal showing HBL-1/GFP expression in hypodermal cells. Lateral seam cells (lines) are shadowed by more GFP expression in hyp7 (magnification, 400). Nucleus of V6 (most-posterior line), green.(B) Expression is largely absent from seam cells in a mid L1 BW1932 animal (lines) but is present in P cells (arrows) (magnification, 630).(C) HBL-1/GFP expression in BW1932 is most intense in embryos (arrowhead), decreases in L1s (line), and is virtually absent in the hypodermis of an L3 animal (arrow) (magnification, 400).(D) Strain BW1981 contains an integrated array similar to BW1932, except that the hbl-1 3'UTR is replaced by the unc-54 3'UTR and the nuclear localization signal on GFP is missing. HBL-1/GFP in the hypodermis of embryos, an L2 animal (bottom), an L3 animal (top), an L4 animal (middle) (except in seam cells, which are shown shadowed by the hyp7 expression), and in the VNC of the L4 (magnification, 400). (C) and (D) were exposed for the same amount of time.(E and F) Nomarski images of the same animals as in (C) and (D), respectively.(G) HBL-1/GFP in BW1932 is most intense in the ventral nerve cord of L3 animals (an early L3 is shown), less intense in an L4 animal, and almost absent in an adult animal.(H) A DIC image of the same animals as in (G).(I) Wild-type BW1932 adult with barely detectable expression of HBL-1/GFP in the VNC, compared with a let-7(n2853) adult, shown in (J).

Picture from Lin X et al. (2003) Curr Biol "C. elegans PAT-6/actopaxin plays a critical role in the assembly of integrin ...."

UNC-89 in wild-type 530 min embryos. Arrows indicate body wall muscle attachments.