title: Differential roles of HOW in male and female Drosophila germline differentiation.
abstract: The adult gonads in both male and female Drosophila melanogaster produce gametes that originate from a regenerative pool of germline stem cells (GSCs). The differentiation programme that produces gametes must be co-ordinated with GSC maintenance and proliferation in order to regulate tissue regeneration. The HOW RNA-binding protein has been shown to maintain mitotic progression of male GSCs and their daughters by maintenance of Cyclin B expression as well as suppressing accumulation of the differentiation factor Bam. Loss of HOW function in the male germline results in loss of GSCs due to a delay in G2 and subsequent apoptosis. Here we show that female how mutant GSCs do not have any cell cycle defects although HOW continues to bind bam mRNA and suppress Bam expression. The role of HOW in suppressing germ cell Bam expression appears to be conserved between sexes, leading to different cellular outcomes in how mutants due to the different functions of Bam. In addition the role in maintaining Cyclin B expression has not been conserved so female how GSCs differentiate rather than arrest.
authors.affiliation: Department of Anatomy and Cell Biology, University of Melbourne, Parkville, Victoria, Australia.
authors.forename: Adrian C
authors.initials: AC
authors.lastname: Monk
authors.forename: Nicole A
authors.initials: NA
authors.lastname: Siddall
authors.forename: Barbara
authors.initials: B
authors.lastname: Fraser
authors.forename: Eileen A
authors.initials: EA
authors.lastname: McLaughlin
authors.forename: Gary R
authors.initials: GR
authors.lastname: Hime
mesh_terms: D000818:Animals; D002453:Cell Cycle; D002454:Cell Differentiation; D049109:Cell Proliferation; D003433:Crosses, Genetic; D019926:Cyclin B / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D004331:Drosophila melanogaster / Q000235:genetics / Q000378:metabolism*; D005260:Female; D005854:Germ Cells / Q000166:cytology; D049452:Green Fluorescent Proteins / Q000378:metabolism; D008297:Male; D008938:Mitosis; D008957:Models, Genetic; D009687:Nuclear Proteins / Q000235:genetics* / Q000502:physiology*; D010053:Ovary / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000502:physiology*; D012737:Sex Factors; D015398:Signal Transduction
chemical_list: D019926:Cyclin B; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C091674:bam protein, Drosophila; C106296:how protein, Drosophila; D049452:Green Fluorescent Proteins