title: Efficiency of spermatogonial dedifferentiation during aging.
abstract: BACKGROUND
  Adult stem cells are critical for tissue homeostasis; therefore, the mechanisms utilized to maintain an adequate stem cell pool are important for the survival of an individual. In Drosophila, one mechanism utilized to replace lost germline stem cells (GSCs) is dedifferentiation of early progenitor cells. However, the average number of male GSCs decreases with age, suggesting that stem cell replacement may become compromised in older flies.
  
  
  RESULTS
  Using a temperature sensitive allelic combination of Stat92E to control dedifferentiation, we found that germline dedifferentiation is remarkably efficient in older males; somatic cells are also effectively replaced. Surprisingly, although the number of somatic cyst cells also declines with age, the proliferation rate of early somatic cells, including cyst stem cells (CySCs) increases.
  
  
  CONCLUSIONS
  These data indicate that defects in spermatogonial dedifferentiation are not likely to contribute significantly to an aging-related decline in GSCs. In addition, our findings highlight differences in the ways GSCs and CySCs age. Strategies to initiate or enhance the ability of endogenous, differentiating progenitor cells to replace lost stem cells could provide a powerful and novel strategy for maintaining tissue homeostasis and an alternative to tissue replacement therapy in older individuals.
authors.affiliation: Laboratory of Genetics, The Salk Institute for Biological Studies, University of California San Diego, La Jolla, California, United States of America.
authors.forename: Chihunt
authors.initials: C
authors.lastname: Wong
authors.forename: D Leanne
authors.initials: DL
authors.lastname: Jones
mesh_terms: D053687:Adult Stem Cells / Q000166:cytology / Q000378:metabolism*; D000375:Aging; D000818:Animals; D054337:Cell Dedifferentiation; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster; D008297:Male; D050791:STAT Transcription Factors / Q000378:metabolism*; D013093:Spermatogonia / Q000166:cytology / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D050791:STAT Transcription Factors; C105675:Stat92E protein, Drosophila