Lung morphogenesis revisited: Old facts, current ideas

Abstract

The anisotropy in the optical absorption and photoconductivity of thin layers of mesomorphic derivatives of hexa‐peri‐hexabenzocoronene (HBC) have been investigated for aligned films prepared via three different methods: deposition on friction‐deposited polytetrafluoroethylene (PTFE), zone‐casting (ZC), and Langmuir–Blodgett (LB) multilayer dipping. The ratio of the optical density for light polarized perpendicular to the alignment direction, OD+, to that for light polarized parallel, OD=, varies from close to 1.0 up to 12.5 depending on whether the HBC cores are tilted at close to 45° or 90° with respect to the axis of the self‐assembled columnar stacks. For all aligned films the photoconductivity, determined using the electrode‐less flash‐photolysis time‐resolved microwave conductivity technique (FP‐TRMC), was found to be favored in the direction of columnar alignment by up to a factor of 30 for a PTFE‐aligned film. The effect of varying the temperature of the films over a range encompassing the temperature at which the transition from the crystalline solid to the columnar mesophase occurs in the bulk materials has been investigated. High‐temperature annealing increases the optical and conductivity anisotropy for the LB film significantly, but has little effect for the PTFE and the ZC films. The relative efficacy of the different alignment procedures is discussed.

Eya1 controls cell polarity, spindle orientation, cell fate and Notch signaling in distal embryonic lung epithelium

“…Mammalian lung development begins when two primary buds consisting of an inner epithelial layer surrounded by mesenchyme, arise from the laryngotracheal groove in the ventral foregut. These buds undergo stereotypic rounds of branching and outgrowth to give rise to a tree-like respiratory organ, which contains different specialized epithelial cell types organized along the proximodistal axis (Cardoso, 2000;Warburton et al, 2000;Warburton, 2008;Metzger et al, 2008). In order to function effectively, the alveolar surface must form a selectively permeable monolayer where cellcell contact provides important spatial cues that are required to generate cell polarity/communications (Nelson, 2003a;Nelson, 2003b;Boitano et al, 2004).…”

Respiratory Distress and Neonatal Lethality in Mice Lacking Golgi α1,2-Mannosidase IB Involved in N-Glycan Maturation

“…␣1,2-Mannosidase IA, IB, and IC cDNA amplicons were generated using the following primer sets: ManIA, 5Ј-CCTCCTGGAACACAAGATG-3Ј and 5Ј-TGCAACATGG-CAAAACATTAC-3Ј; ManIB, 5Ј-GATAGTTTTTATGAA-TACTTACTG-3Ј and 5Ј-TAGCTCCTGTAAGGTGCTC-3Ј; ManIC, 5Ј-GTCCTATGCCCGCTCAGA-3Ј and 5Ј-CTGTC-TCCTCACAGAGGAA-3Ј. The amplicons were ligated into the TOPO-TA vector (Invitrogen), and used as templates to prepare gene-specific sense and antisense 35 S-labeled cRNA probes for hybridization to cryosections of mouse embryos fixed in 4% formaldehyde. The sections were exposed to Kodak BioMax film for 24 h, as described previously (27,28).…”

Tissue‐ and development‐dependent expression of the small GTPase Arf6 in mice

“…The proximal buds later develop into airway bronchi, which contain secretory and neuroendocrine cells, whereas the distal buds become alveoli, which contain type I and II alveolar epithelial cells (Cardoso, 2000;Okubo et al, 2005).…”