From the authors [4]

[No abstract available

Evidence for multiple roles for grainyheadlike 2 in the establishment and maintenance of human mucociliary airway epithelium

Most of the airways of the human lung are lined by an epithelium made up of ciliated and secretory luminal cells and undifferentiated basal progenitor cells. The integrity of this epithelium and its ability to act as a selective barrier are critical for normal lung function. In other epithelia, there is evidence that transcription factors of the evolutionarily conserved grainyheadlike (GRHL) family play key roles in coordinating multiple cellular processes required for epithelial morphogenesis, differentiation, remodeling, and repair. However, only a few target genes have been identified, and little is known about GRHL function in the adult lung. Here we focus on the role of GRHL2 in primary human bronchial epithelial cells, both as undifferentiated progenitors and as they differentiate in air-liquid interface culture into an organized mucociliary epithelium with transepithelial resistance. Using a dominant-negative protein or shRNA to inhibit GRHL2, we follow changes in epithelial phenotype and gene transcription using RNA sequencing or microarray analysis. We identify several hundreds of genes that are directly or indirectly regulated by GRHL2 in both undifferentiated cells and air-liquid interface cultures. Using ChIP sequencing to map sites of GRHL2 binding in the basal cells, we identify 7,687 potential primary targets and confirm that GRHL2 binding is strongly enriched near GRHL2-regulated genes. Taken together, the results support the hypothesis that GRHL2 plays a key role in regulating many physiological functions of human airway epithelium, including those involving cell morphogenesis, adhesion, and motility

Mouse Small eye results from mutations in a paired-like homeobox-containing gene.

Small eye (Sey) in mouse is a semidominant mutation which in the homozygous condition results in the complete lack of eyes and nasal primordia. On the basis of comparative mapping studies and on phenotypic similarities, Sey has been suggested to be homologous to congenital aniridia (lack of iris) in human1,2. A candidate gene for the aniridia (AN) locus at 11p13 has been isolated by positional cloning3 and its sequence and that of the mouse homologue has been established (C.T., manuscript in preparation). This gene belongs to the paired-like class of developmental genes first described in Drosophila which contain two highly conserved motifs, the paired box and the homeobox 4,5. In vertebrates, genes which encode the single paired domain as well as those which express both motifs have been described as the Pax multigene family6-10. A Pax gene recently described as Pax-611,12 is identical to the mouse homologue of the candidate aniridia gene. Here we report the analysis of three independent Sey alleles and show that indeed this gene is mutated and that the mutations would predictably interrupt gene function

Patterned delivery and expression of gene constructs into zebrafish embryos using microfabricated interfaces

We demonstrate a method which uses simple microfabrication and microfluidics to produce custom, shaped electroporators for the patterned delivery of foreign molecules into developing embryos. We show how these electroporators can be used to 'draw' two-dimensional patterns of tracer molecules, DNA and mRNA into the yolk and cells of zebrafish embryos (Danio rerio) at different stages of development. We demonstrate the successful delivery of patterns of Trypan Blue (normal dye), Texas Red (fluorescent dye), GFP-expressing DNA plasmids and GFP expressing mRNA constructs into both chorionated and dechorionated embryos. Both DNA and mRNA were expressed in the desired patterns subsequent to delivery. Square pulses of 10-20 V (0.20-0.40 kV/cm), 50-100 ms width were sufficient to create transient pores and introduce compounds from the late blastula period (3 hpf) to early pharyngula period (24 hpf) embryos. Using 24 hpf dechorionated embryos, we achieved a high survival of 91.3% and 89%, and a delivery efficiency of 38% and 50% for GFP-DNA and GFP-mRNA respectively. Lastly, we demonstrate the simultaneous delivery of different compounds into the developing embryo.close8