Ectopic activation of Dpp signalling in the male Drosophila germline inhibits germ cell differentiation.
The mechanisms that control differentiation of stem cells to specialised cell types probably include factors intrinsic to stem cells as well as extrinsic factors produced by the microenvironment of the stem cell niche. The Drosophila male germline is renewed from a population of stem cells located in the apical tip of the adult testis. The morphological relationship between germline stem cells and their surrounding somatic cells is well understood but the factors that regulate stem cell proliferation and differentiation are still being uncovered. This study examined the effect of stimulating Dpp signalling directly in male germ cells. Ectopic Dpp or Activin signalling resulted in overproliferation of both stem cell-like and spermatogonial-like cells in the apical region of the testis. A third cell population that expressed stem cell markers was seen to proliferate in the distal testis when Dpp signalling was either stimulated or repressed in germline stem cells.
Bunt
Stephanie M
SM
Department of Anatomy and Cell Biology, University of Melbourne, Victoria, Australia.
Hime
Gary R
GR
D028341:Activins / Q000502:physiology; D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D049109:Cell Proliferation; D029721:Drosophila Proteins / Q000378:metabolism* / Q000502:physiology; D004331:Drosophila melanogaster / Q000502:physiology*; D005854:Germ Cells / Q000166:cytology*; D008297:Male; D015398:Signal Transduction / Q000502:physiology*; D013093:Spermatogonia / Q000166:cytology / Q000502:physiology; D013234:Stem Cells / Q000502:physiology; D013737:Testis / Q000166:cytology; D016212:Transforming Growth Factor beta / Q000378:metabolism
C108633:Dad protein, Drosophila; D029721:Drosophila Proteins; D016212:Transforming Growth Factor beta; C064196:dpp protein, Drosophila; D028341:Activins