The study investigates the mechanisms underlying the directional migration of tracheal stem cells (progenitors) in Drosophila. The key findings are:
The fat body, the functional analog of mammalian adipose tissue, is essential for maintaining the disciplined, anterior-to-posterior migration of tracheal progenitors. Disruption of the fat body leads to bidirectional, undisciplined movement of the progenitors.
The fat body-derived cytokine Upd2 targets the tracheal progenitors and activates the JAK/STAT signaling pathway in these cells. Knockdown of Upd2 or components of the JAK/STAT pathway (Dome, Hop, Stat92E) phenocopies the bidirectional migration observed upon fat body disruption.
JAK/STAT signaling in the tracheal progenitors promotes the expression of genes involved in planar cell polarity (PCP), such as Dachsous, Four-jointed, Frizzled, and Fat2. Disruption of these PCP components also leads to undisciplined progenitor migration.
Upd2 is transported from the fat body to the tracheal progenitors through a vesicular trafficking mechanism involving Rab5, Rab7, Grasp65, and the tetraspanin Lbm. Perturbation of this vesicular transport system impairs JAK/STAT signaling and the disciplined migration of progenitors.
In summary, the study uncovers an inter-organ communication mechanism involving the fat body-derived cytokine Upd2, which regulates the directional migration of tracheal stem cells through the activation of JAK/STAT signaling and the modulation of planar cell polarity.
To Another Language
from source content
biorxiv.org
Key Insights Distilled From
by Huang,H., Do... at www.biorxiv.org 07-05-2024
https://www.biorxiv.org/content/10.1101/2024.07.03.601877v2Deeper Inquiries