title: Polycomb group genes Psc and Su(z)2 maintain somatic stem cell identity and activity in Drosophila.
abstract: Adult stem cells are essential for the proper function of many tissues, yet the mechanisms that maintain the proper identity and regulate proliferative capacity in stem cell lineages are not well understood. Polycomb group (PcG) proteins are transcriptional repressors that have recently emerged as important regulators of stem cell maintenance and differentiation. Here we describe the role of Polycomb Repressive Complex 1 (PRC1) genes Posterior sex combs (Psc) and Suppressor of zeste two (Su(z)2) in restricting the proliferation and maintaining the identity of the Cyst Stem Cell (CySC) lineage in the Drosophila testis. In contrast, Psc and Su(z)2 seem to be dispensable for both germline stem cell (GSC) maintenance and germ cell development. We show that loss of Psc and Su(z)2 function in the CySC lineage results in the formation of aggregates of mutant cells that proliferate abnormally, and display abnormal somatic identity correlated with derepression of the Hox gene Abdominal-B. Furthermore, we show that tumorigenesis in the CySC lineage interferes non-cell autonomously with maintenance of GSCs most likely by displacing them from their niche.
authors.affiliation: Department of Developmental Biology, School of Medicine, Stanford University, Stanford, California, United States of America.
authors.forename: Jose Rafael
authors.initials: JR
authors.lastname: Morillo Prado
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.forename: Margaret T
authors.initials: MT
authors.lastname: Fuller
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D002454:Cell Differentiation / Q000235:genetics; D019070:Cell Lineage / Q000235:genetics; D049109:Cell Proliferation; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics / Q000378:metabolism; D004625:Embryo, Nonmammalian; D005260:Female; D008297:Male; D063150:Polycomb Repressive Complex 1 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D063146:Polycomb-Group Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D013234:Stem Cells / Q000166:cytology / Q000502:physiology*; D013737:Testis / Q000166:cytology / Q000196:embryology / Q000254:growth & development / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; D063146:Polycomb-Group Proteins; C071051:Su(z)2 protein, Drosophila; C071050:Psc protein, Drosophila; D063150:Polycomb Repressive Complex 1