Picture from Baum PD et al. (1999) Genes Dev "The Caenorhabditis elegans gene ham-2 links Hox patterning to migration of the ...."

Figure 4. HAM-2 protein is expressed in the HSN nucleus during migration. Fluorescence photomicrographs of wild-type (A- F) and ham-2(mu1) mutant (G-I) embryos that have been stained with DAPI (blue), an UNC-86 antiserum (green) and a HAM-2 antiserum (red). Each panel presents a left lateral view of the embryo, with the developing tail to the left, the head to the right and the end of the tail and the top of the head both oriented upwards. The right sides are out of focus. (A-C) A wild-type embryo at ~410 min after first cleavage, in which the HSN has not migrated out of the tail. (A) DAPI staining. The nuclei of the HSN (large arrow) and the ALN/PLM precursor (small arrow) are shown. (B) Anti-UNC-86 staining. Both the HSN (large arrow) and the ALN/PLM precursor (small arrow) express UNC-86. (C) Anti-HAM-2 staining. The HSN nucleus (large arrow) expresses HAM-2; several HAM-2 expressing cells in the head are out of focus. (D-F) A wild-type embryo at ~430 min after first cleavage. (D) DAPI staining reveals the position of the HSN nucleus (arrow). The ALN/PLM precursor nucleus is out of the plane of focus. (E) Anti-UNC-86 staining. Shortly after commencing its anteriorly directed migration, the HSN begins expressing UNC-86 (arrow; Finney and Ruvkun 1990). (F) Anti-HAM-2 staining. During its migration, the HSN also expresses HAM-2 (arrow). (G-I) A ham-2(mu1) mutant embryo at ~430 min after first cleavage. (G) DAPI staining reveals the positions of the HSN (large arrow) and the ALN/PLM precursor (small arrow) nuclei. (H) Anti-UNC-86 staining. The HSN (large arrow) and ALN/PLM precursor (small arrow) show normal expression of UNC-86. (I) Anti-HAM-2 staining. Although expression of HAM-2 in the head (mostly out of focus) and in the hypodermis (at an earlier stage not shown here) are normal, the HSN does not express HAM-2 in ham-2(mu1) embryos. The HSNs also lack HAM-2 expression in ham2(n1332) animals (not shown). Scale bar, 5 μm.

Picture from Baum PD et al. (1999) Genes Dev "The Caenorhabditis elegans gene ham-2 links Hox patterning to migration of the ...."

Figure 4. HAM-2 protein is expressed in the HSN nucleus during migration. Fluorescence photomicrographs of wild-type (A- F) and ham-2(mu1) mutant (G-I) embryos that have been stained with DAPI (blue), an UNC-86 antiserum (green) and a HAM-2 antiserum (red). Each panel presents a left lateral view of the embryo, with the developing tail to the left, the head to the right and the end of the tail and the top of the head both oriented upwards. The right sides are out of focus. (A-C) A wild-type embryo at 410 min after first cleavage, in which the HSN has not migrated out of the tail. (A) DAPI staining. The nuclei of the HSN (large arrow) and the ALN / PLM precursor (small arrow) are shown. (B) Anti-UNC-86 staining. Both the HSN (large arrow) and the ALN/PLM precursor (small arrow) express UNC-86. (C) Anti-HAM-2 staining. The HSN nucleus (large arrow) expresses HAM-2; several HAM-2 expressing cells in the head are out of focus. (D-F) A wild-type embryo at 430 min after first cleavage. (D) DAPI staining reveals the position of the HSN nucleus (arrow). The ALN/PLM precursor nucleus is out of the plane of focus. (E) Anti-UNC-86 staining. Shortly after commencing its anteriorly directed migration, the HSN begins expressing UNC-86 (arrow; Finney and Ruvkun 1990). (F) Anti-HAM-2 staining. During its migration, the HSN also ex- presses HAM-2 (arrow). (G-I) A ham-2(mu1) mutant embryo at 430 min after first cleavage. (G) DAPI staining reveals the positions of the HSN (large arrow) and the ALN/PLM precursor (small arrow) nuclei. (H) Anti-UNC-86 staining. The HSN (large arrow) and ALN/PLM precursor (small arrow) show normal ex- pression of UNC-86. (I) Anti-HAM-2 staining. Although expression of HAM-2 in the head (mostly out of focus) and in the hypodermis (at an earlier stage not shown here) are normal, the HSN does not express HAM-2 in ham-2(mu1) embryos. The HSNs also lack HAM-2 expression in ham2(n1332) animals (not shown). Scale bar, 5 um.

Picture from Guenther C et al. (1996) Development "Asymmetric distribution of the C. elegans HAM-1 protein in neuroblasts enables ...."

Figure 2. HAM-1 expression in wild-type and ham-1 mutant embryos. (A-E) Fluorescence photomicrographs of embryos stained with DAPI (blue) and a mouse anti-HAM-1 antiserum (red). (A-C, E,F) wild-type embryos, (D) ham-1 mutant embryos. (A) Earliest expression of HAM-1 begins at the 28-cell stage of development. At this stage, HAM-1 is restricted to the cell periphery to one side of dividing cells (crescent staining). The large arrow points to the asymmetrically distributed HAM-1 protein of a dividing cell and the small arrow points to the condensed chromosomes in the same cell. (B) Fluorescence photomicrograph of an embryo later in development (mid-gastrulation) that has been stained with an anti-HAM-1 antiserum. The small arrows point to two nuclei that have just formed at the end of cell division. HAM-1 protein is associated with the plasma membrane of the posterior nucleus. (C,D) Embryos at approximately 280 minutes after the division of the zygote. (C) Ventral view of a wild-type embryo. At this stage, both rings (arrowhead) and crescents (arrows) of HAM-1 protein are visible. The arrows mark the asymmetric distribution of HAM-1 in the HSN/PHB (right arrow) and ALN/PLM (left arrow) neuroblasts prior to their divisions. (D) Ventral view of a ham-1(n1438) embryo. The small arrow indicates the only detectable HAM-1 expression in this embryo. This embryo is in the same orientation and at the same stage as the wild-type embryo in C. The large arrows mark the HSN/PHB (right arrow) and ALN/PLM (left arrow) neuroblasts that are not expressing HAM-1 protein. (E) Merged image showing DAPI and anti-HAM-1 staining of the same embryo as in C. The arrow points to HAM-1 localization at the posterior cell periphery of the HSN/PHB neuroblast. This portion of the neuroblast will be inherited by the HSN/PHB precursor upon division. (F) LIN-26 staining in the same embryo as in C and E. LIN-26 is not expressed in the HSN/PHB neuroblast (arrow). The asterisk in E and F marks the position of a nucleus that is expressing LIN-26 for reference. Scale bar, 5 µm.

Picture from Guenther C et al. (1996) Development "Asymmetric distribution of the C. elegans HAM-1 protein in neuroblasts enables ...."

HAM-1 expression in wild-type embryos. (A-E) Fluorescence photomicrographs of embryos stained with DAPI (blue) and a mouse anti-HAM-1 antiserum (red). (A) Earliest expression of HAM-1 begins at the 28-cell stage of development. At this stage, HAM-1 is restricted to the cell periphery to one side of dividing cells (crescent staining). The large arrow points to the asymmetrically distributed HAM-1 protein of a dividing cell and the small arrow points to the condensed chromosomes in the same cell. (B) Fluorescence photomicrograph of an embryo later in development (mid-gastrulation) that has been stained with an anti-HAM-1 antiserum. The small arrows point to two nuclei that have just formed at the end of cell division. HAM-1 protein is associated with the plasma membrane of the posterior nucleus. (C) Embryos at approximately 280 minutes after the division of the zygote. Ventral view of a wild-type embryo. At this stage, both rings (arrowhead) and crescents (arrows) of HAM-1 protein are visible. The arrows mark the asymmetric distribution of HAM-1 in the HSN/PHB (right arrow) and ALN/PLM (left arrow) neuroblasts prior to their divisions. (E) Merged image showing DAPI and anti-HAM-1 staining of the same embryo as in C. The arrow points to HAM-1 localization at the posterior cell periphery of the HSN/PHB neuroblast. This portion of the neuroblast will be inherited by the HSN/PHB precursor upon division. (F) LIN-26 staining in the same embryo as in C and E. LIN-26 is not expressed in the HSN/PHB neuroblast (arrow). The asterisk in E and F marks the position of a nucleus that is expressing LIN-26 for reference. Scale bar, 5 µm.

Picture from Singhvi A et al. (2008) Genetics "The T-box gene tbx-2, the homeobox gene egl-5 and the asymmetric cell division ...."

Figure 10. Model summarizing genetic data implicating TBX-2, HAM-1, and EGL-5 as regulators of the survival and fate of the precursor cell, the HSN neuron, and the PHB neuron, as well as migration of the HSN neuron. We propose that egl-5 acts to promote HSN development and to inhibit PHB fate in the HSNs. These models are not mutually exclusive. By inhibiting PHB fate, for example, egl-5 could promote the expression of HSN traits.