The germline stem cells of Drosophila melanogaster partition DNA non-randomly.
The Immortal Strand Hypothesis proposes that asymmetrically dividing stem cells cosegregate chromatids to retain ancestral DNA templates. Using both pulse-chase and label retention assays, we show that non-random partitioning of DNA occurs in germline stem cells (GSCs) in the Drosophila ovary as these divide asymmetrically to generate a new GSC and a differentiating cystoblast. This process is disrupted when GSCs are forced to differentiate through the overexpression of Bag of Marbles, a factor that impels the terminal differentiation of cystoblasts. When Decapentaplegic, a ligand which maintains the undifferentiated state of GSCs, is expressed ectopically the non-random partitioning of DNA is similarly disrupted. Our data suggest asymmetric chromatid segregation is coupled to mechanisms specifying cellular differentiation via asymmetric stem cell division.
Karpowicz
Phillip
P
Department of Medical Genetics and Microbiology, University of Toronto, 160 College Street, Toronto, Ontario, Canada M5S 3E1. phillip.karpowicz@utoronto.ca
Pellikka
Milena
M
Chea
Evelyn
E
Godt
Dorothea
D
Tepass
Ulrich
U
van der Kooy
Derek
D
D000818:Animals; D002455:Cell Division / Q000502:physiology*; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics; D005260:Female; D010053:Ovary / Q000166:cytology; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*
D029721:Drosophila Proteins; D004247:DNA