title: The actin-binding protein profilin is required for germline stem cell maintenance and germ cell enclosure by somatic cyst cells.
abstract: Specialized microenvironments, or niches, provide signaling cues that regulate stem cell behavior. In the Drosophila testis, the JAK-STAT signaling pathway regulates germline stem cell (GSC) attachment to the apical hub and somatic cyst stem cell (CySC) identity. Here, we demonstrate that chickadee, the Drosophila gene that encodes profilin, is required cell autonomously to maintain GSCs, possibly facilitating localization or maintenance of E-cadherin to the GSC-hub cell interface. Germline specific overexpression of Adenomatous Polyposis Coli 2 (APC2) rescued GSC loss in chic hypomorphs, suggesting an additive role of APC2 and F-actin in maintaining the adherens junctions that anchor GSCs to the niche. In addition, loss of chic function in the soma resulted in failure of somatic cyst cells to maintain germ cell enclosure and overproliferation of transit-amplifying spermatogonia.
authors.affiliation: Department of Genetics, Stanford University, School of Medicine, Stanford, CA 94305, USA.
authors.forename: Alicia R
authors.initials: AR
authors.lastname: Shields
authors.forename: Allyson C
authors.initials: AC
authors.lastname: Spence
authors.forename: Yukiko M
authors.initials: YM
authors.lastname: Yamashita
authors.forename: Erin L
authors.initials: EL
authors.lastname: Davies
authors.forename: Margaret T
authors.initials: MT
authors.lastname: Fuller
mesh_terms: D000199:Actins / Q000378:metabolism; D022005:Adherens Junctions / Q000378:metabolism; D000818:Animals; D015820:Cadherins / Q000378:metabolism; D002454:Cell Differentiation; D019070:Cell Lineage; D049109:Cell Proliferation; D029721:Drosophila Proteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D008297:Male; D051304:Profilins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D015398:Signal Transduction / Q000235:genetics; D013093:Spermatogonia / Q000166:cytology / Q000378:metabolism; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism*; D055153:Stem Cell Niche; D013234:Stem Cells / Q000378:metabolism*; D025521:Tumor Suppressor Proteins / Q000096:biosynthesis / Q000378:metabolism*
chemical_list: C467323:APC2 protein, Drosophila; D000199:Actins; D015820:Cadherins; D029721:Drosophila Proteins; D051304:Profilins; D034741:RNA, Small Interfering; D025521:Tumor Suppressor Proteins; C091674:bam protein, Drosophila; C495737:chic protein, Drosophila
keywords: APC2; Profilin; Stem cells