02123nas a2200181   4500008004100000020002300041245020200064210006900266260006300335300001300398490000700411520137800418100003101796700002001827700001901847700001801866856005701884       2016                        eng d  a1553-73901553-740400aGermline Defects Caused by Smed-boule RNA-Interference Reveal That Egg Capsule Deposition Occurs Independently of Fertilization, Ovulation, Mating, or the Presence of Gametes in Planarian Flatworms0 aGermline Defects Caused by Smedboule RNAInterference Reveal That  aSan Francisco, CA USAbPublic Library of Sciencec2016/05/  ae10060300 v123 aFew animals are known to lay eggs in the absence of ovulation or copulation, as it is presumably energetically wasteful and subjected to negative selection. Characterization of Smed-boule, a member of the DAZ family of germline RNA-binding proteins, revealed that egg capsule (or capsule) production and deposition occurs independently of the presence of gametes in the planarian flatworm Schmidtea mediterranea. Reduction of Smed-boule expression by RNA-interference (RNAi) causes ablation of spermatogonial stem cells and the inability of ovarian germline stem cells to undergo oogenesis. Although animals subjected to Smed-boule RNAi lose their gametes and become sterile, they continue to lay egg capsules. Production of sterile capsules is even observed in virgin Smed-boule(RNAi) and control planarians maintained in complete isolation, demonstrating that egg production in S. mediterranea occurs independently of ovulation, fertilization, or mating. Evidence suggests that this is a conserved feature amongst Platyhelminthes, and therefore relevant to the pathology and dissemination of parasitic flatworms. These findings demonstrate that Smed-boule functions at different stages during male and female germline stem cell development, and also demonstrate that egg capsule production by planarian flatworms occurs independently of signals produced by mating or ova.1 aSteiner, Jessica, Kathryne1 aTasaki, Junichi1 aRouhana, Labib1 aHawley, Scott  uhttp://www.ncbi.nlm.nih.gov/pmc/articles/PMC4858218/