Wnt/beta-catenin--a canonical tale of cell-fate choice in the vertebrate skeleton.

Three exciting papers in this issue of Developmental Cell provide new insights into the regulation of chondrocytic, osteoblastic, and osteoclastic differentiation during skeletal development and postnatal growth. The studies demonstrate that Wnt/beta-catenin signaling represents both a mechanism in mesenchymal precursor cells for selecting between chondrocytic and osteoblastic fates as well as a mechanism in osteoblasts for stimulating the production of an inhibitor of osteoclast formation.

The effect of sub-lethal ALA-PDT on the cytoskeleton and adhesion of cultured human cancer cells.

5-Aminolevulinic acid (ALA), a precursor of the endogenous photosensitizer protoporphyrin IX, is used in the photodynamic therapy (PDT) of cancer. Sub-lethal ALA-PDT (1-min irradiation with 370-450 nm blue light, 0.6 mW/cm(2) after 2-h incubation with 1 mM ALA) has been earlier shown to change cell morphology and to inhibit both trypsin-induced detachment of cultured cancer cells from the plastic substrata and cell attachment to the bottom of the plastic well plates.

Deletion mutant of FGFR4 induces onion-like membrane structures in the nucleus.

The expression of several deletion mutants of fibroblast growth factor receptor 4 (FGFR4) was studied in COS-1 cells. FGFR4-mutants lacking most of the extracellular region did not efficiently reach the plasma membrane but accumulated in the endoplasmic reticulum (ER) and Golgi body. A mutant FGFR4 lacking the kinase domain as well as most of the extracellular region (DeltaExt/R4Tth) had a distinct intracellular distribution.

Characterization and tissue expression of acidic fibroblast growth factor binding protein homologue in Drosophila melanogaster.

We have earlier reported a Drosophila protein, which aligned significantly with the amino acid sequence of the human acidic fibroblast growth factor intracellular binding protein (FIBP). In attempts to further elucidate the function of FIBP and its putative role in fibroblast growth factor (FGF) signaling we have cloned and characterized FIBP from Drosophila melanogaster (DrFIBP). Using comparative sequence analysis of Drosophila and human FIBP genes we demonstrate a remarkable conservation of their structural architecture suggesting that FIBP from vertebrates and insects are genuine homologues.