Piwi is required in multiple cell types to control germline stem cell lineage development in the Drosophila ovary. - Xing Ma; Su Wang; Trieu Do; Xiaoqing Song; Mayu Inaba; Yoshiya Nishimoto; Lu-ping Liu; Yuan Gao; Ying Mao; Hui Li; William McDowell; Jungeun Park; et al. (PLoS ONE, 2014)