Germline stem cells in the Drosophila ovary descend from pole cells in the anterior region of the embryonic gonad
2004
A fundamental yet unexplored question in stem cell biology is how the fate
of tissue stem cells is initially determined during development. In
Drosophila, germline stem cells (GSCs) descend from a subset of
primordial germ cells (PGCs) at the onset of oogenesis. GSC determination may
occur at the onset of oogenesis when a subset of PGCs is induced to become
GSCs by contacting niche cells. Alternatively, the GSC fate could be
predetermined for a subset of PGCs before oogenesis, due to either their
interaction with specific somatic cells in the embryonic/larval gonads, or
their inherently heterogeneous potential in becoming GSCs, or both. Here, we
show that anterior somatic cells in the embryonic gonad already differ from
posterior somatic cells and are likely to be the precursors of niche cells in
the adult ovary. Furthermore, only pole cells in the anterior half of the
embryonic gonad give rise to the PGCs that frequently acquire contact with
nascent niche cells in the late larval ovary. Eventually, only these
contacting PGCs become GSCs, whereas non-contacting PGCs directly
differentiate into cystoblasts. The strong preference of these `anterior PGCs9
towards contacting niche cells does not require DE-cadherin-mediated adhesion
and is not correlated with either orientation or rate of their divisions.
These data suggest that the GSC fate is predetermined before oogenesis. The
predetermination probably involves soma/pole-cell interaction in the anterior
half of the embryonic gonad, followed by an active homing mechanism during PGC
proliferation to maintain the contact between the `anterior PGCs9 and anterior
somatic cells.
Keywords:
- Correction
- Source
- Cite
- Save
- Machine Reading By IdeaReader
49
References
55
Citations
NaN
KQI