Activation of the WNT-BMP-FGF Regulatory Network Induces the Onset of Cell Death in Anterior Mesodermal Cells to Establish the ANZ.

The spatiotemporal control of programmed cell death (PCD) plays a significant role in sculpting the limb. In the early avian limb bud, the anterior necrotic zone (ANZ) and the posterior necrotic zone are two cell death regions associated with digit number reduction. In this study, we evaluated the first events triggered by the FGF, BMP, and WNT signaling interactions to initiate cell death in the anterior margin of the limb to establish the ANZ.

Stereological Quantification of Cell-Cycle Kinetics and Mobilization of Epithelial Stem Cells during Wound Healing.

We describe a stereology method to obtain reliable estimates of the total number of proliferative and migratory epithelial cells after wounding. Using pulse and chase experiments with halogenated thymidine analogs such as iododeoxyuridine (IdU) and chlorodeoxyuridine (CldU), it is possible to track epithelial populations with heterogeneous proliferative characteristics through skin compartments. The stereological and tissue processing methods described here apply widely to address important questions of skin stem-cell biology.

Irx1 and Irx2 are coordinately expressed and regulated by retinoic acid, TGFβ and FGF signaling during chick hindlimb development.

The Iroquois homeobox (Irx) genes play a crucial role in the regionalization and patterning of tissues and organs during metazoan development. The Irx1 and Irx2 gene expression pattern during hindlimb development has been investigated in different species, but its regulation during hindlimb morphogenesis has not been explored yet. The aim of this study was to evaluate the gene expression pattern of Irx1 and Irx2 as well as their regulation by important regulators of hindlimb development such as retinoic acid (RA), transforming growth factor β (TGFβ) and fibroblast growth factor (FGF) signaling during chick hindlimb development.

Modulatory role of sensory innervation on hair follicle stem cell progeny during wound healing of the rat skin.

Background: The bulge region of the hair follicle contains resident epithelial stem cells (SCs) that are activated and mobilized during hair growth and after epidermal wounding. However, little is known about the signals that modulate these processes. Clinical and experimental observations show that a reduced supply of sensory innervation is associated with delayed wound healing.