title: Caprin controls follicle stem cell fate in the Drosophila ovary.
abstract: Adult stem cells must balance self-renewal and differentiation for tissue homeostasis. The Drosophila ovary has provided a wealth of information about the extrinsic niche signals and intrinsic molecular processes required to ensure appropriate germline stem cell renewal and differentiation. The factors controlling behavior of the more recently identified follicle stem cells of the ovary are less well-understood but equally important for fertility. Here we report that translational regulators play a critical role in controlling these cells. Specifically, the translational regulator Caprin (Capr) is required in the follicle stem cell lineage to ensure maintenance of this stem cell population and proper encapsulation of developing germ cells by follicle stem cell progeny. In addition, reduction of one copy of the gene fmr1, encoding the translational regulator Fragile X Mental Retardation Protein, exacerbates the Capr encapsulation phenotype, suggesting Capr and fmr1 are regulating a common process. Caprin was previously characterized in vertebrates as Cytoplasmic Activation/Proliferation-Associated Protein. Significantly, we find that loss of Caprin alters the dynamics of the cell cycle, and we present evidence that misregulation of CycB contributes to the disruption in behavior of follicle stem cell progeny. Our findings support the idea that translational regulators may provide a conserved mechanism for oversight of developmentally critical cell cycles such as those in stem cell populations.
authors.affiliation: The Section of Molecular Cell and Developmental Biology and the Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America.
authors.forename: John
authors.initials: J
authors.lastname: Reich
authors.forename: Ophelia
authors.initials: O
authors.lastname: Papoulas
mesh_terms: D000818:Animals; D002453:Cell Cycle / Q000235:genetics; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D019926:Cyclin B / Q000235:genetics / Q000378:metabolism; D004330:Drosophila / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D005260:Female; D051860:Fragile X Messenger Ribonucleoprotein 1 / Q000235:genetics / Q000378:metabolism; D018628:Gene Dosage; D005854:Germ Cells / Q000166:cytology / Q000378:metabolism*; D006080:Ovarian Follicle / Q000502:physiology*; D014176:Protein Biosynthesis; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*
chemical_list: D018797:Cell Cycle Proteins; D019926:Cyclin B; D029721:Drosophila Proteins; D051860:Fragile X Messenger Ribonucleoprotein 1; C574686:Capr protein, Drosophila; C503698:CycB protein, Drosophila; C467328:FMR1 protein, Drosophila