Spoltud-1 is a chromatoid body component required for planarian long-term stem cell self-renewal.
Freshwater planarians exhibit a striking power of regeneration, based on a population of undifferentiated totipotent stem cells, called neoblasts. These somatic stem cells have several characteristics resembling those of germ line stem cells in other animals, such as the presence of perinuclear RNA granules (chromatoid bodies). We have isolated a Tudor domain-containing gene in the planarian species Schmidtea polychroa, Spoltud-1, and show that it is expressed in neoblast cells, germ line cells and central nervous system, and during embryonic development. Within the neoblasts, Spoltud-1 protein is enriched in chromatoid bodies. Spoltud-1 RNAi eliminates protein expression after 3 weeks, and abolishes the power of regeneration of planarians after 7 weeks. Neoblast cells are eliminated by the RNAi treatment, disappearing at the end rather than gradually during the process. Neoblasts with no detectable Spoltud-1 protein are able to proliferate and differentiate. These results suggest that Spoltud-1 is required for long term stem cell self renewal.
Solana
Jordi
J
Departament de Genètica, Facultat de Biologia, Av. Diagonal 645, Edifici Annex, Planta 1, 08028 Barcelona, Catalunya, Spain. jsolana@ub.edu
Lasko
Paul
P
Romero
Rafael
R
D000818:Animals; D002454:Cell Differentiation / Q000502:physiology*; D049109:Cell Proliferation; D002490:Central Nervous System / Q000196:embryology / Q000378:metabolism; D005854:Germ Cells / Q000502:physiology*; D015801:Helminth Proteins / Q000502:physiology*; D010932:Planarians / Q000196:embryology / Q000502:physiology*; D012038:Regeneration / Q000502:physiology; D039901:Totipotent Stem Cells / Q000166:cytology* / Q000502:physiology
D015801:Helminth Proteins