|
|
|
|||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
First published online 15 November 2006
doi: 10.1242/dev.02688
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Division of Developmental Biology, Cincinnati Children's Hospital Research
Foundation, Cincinnati, OH 45229, USA.
2 Department of Genetics, School of Medicine, Case Western Reserve University,
Cleveland, OH 44106, USA.
3 Department of Environmental Health, College of Medicine, University of
Cincinnati, Cincinnati, OH 45229, USA.
* Author for correspondence (e-mail: christopher.wylie{at}cchmc.org)
Accepted 10 October 2006
During germ-cell migration in the mouse, the dynamics of embryo growth cause many germ cells to be left outside the range of chemoattractive signals from the gonad. At E10.5, movie analysis has shown that germ cells remaining in the midline no longer migrate directionally towards the genital ridges, but instead rapidly fragment and disappear. Extragonadal germ cell tumors of infancy, one of the most common neonatal tumors, are thought to arise from midline germ cells that failed to die. This paper addresses the mechanism of midline germ cell death in the mouse. We show that at E10.5, the rate of apoptosis is nearly four-times higher in midline germ cells than those more laterally. Gene expression profiling of purified germ cells suggests this is caused by activation of the intrinsic apoptotic pathway. We then show that germ cell apoptosis in the midline is activated by down-regulation of Steel factor (kit ligand) expression in the midline between E9.5 and E10.5. This is confirmed by the fact that removal of the intrinsic pro-apoptotic protein Bax rescues the germ-cell apoptosis seen in Steel null embryos. Two interesting things are revealed by this: first, germ-cell proliferation does not take place in these embryos after E9.0; second, migration of germ cells is highly abnormal. These data show first that changing expression of Steel factor is required for normal midline germ cell death, and second, that Steel factor is required for normal proliferation and migration of germ cells.
Key words: Germ cells, Steel factor (Kitl), Apoptosis, Migration, Mouse
This article has been cited by other articles:
![]() |
J. D. Heaney, M.-Y. J. Lam, M. V. Michelson, and J. H. Nadeau Loss of the Transmembrane but not the Soluble Kit Ligand Isoform Increases Testicular Germ Cell Tumor Susceptibility in Mice Cancer Res., July 1, 2008; 68(13): 5193 - 5197. [Abstract] [Full Text] [PDF] |
||||
![]() |
B. Boldajipour and E. Raz What Is Left Behind--Quality Control in Germ Cell Migration Sci. Signal., April 24, 2007; 2007(383): pe16 - pe16. [Abstract] [Full Text] [PDF] |
||||