Response to Zhang et al

Abstract

Two recent reports by Zhang et al published in Nov (2011) and our group (Anand & Kai, 2012; published online in Dec 2011) have suggested a role for the conserved Tudor domain protein encoded by qin as a component of piRNA pathway. Both studies agree that qin plays a role in the piRNA pathway and is required to repress reteroelements but differ in some aspects of their conclusions about qin function. We reported that kumo M41‐13 , hereafter designated qin kumo , homozygous females exhibited mislocalization of many piRNA pathway components from the nuage, a perinuclear structure where piRNA pathway components are concentrated in the ovary. We also reported a reduction in piRNAs targeting transposons (Supplementary Table 3 in Anand & Kai, 2012). In contrast, Zhang et al found no change in localization of piRNA pathway components to the nuage and observed an increase in Aubergine(Aub)‐Aub homotypic ping‐pong in the qin 1 /Df alleleic combination, which led Zhang et al to propose that qin is required for maintenance of heterotypic, Aub‐Argonaute3 (Ago3) ping‐pong (Zhang et al , 2011). In the accompanying Correspondence, Zhang et al challenge some of our findings. The key issue is whether the localization of piRNA pathway proteins to the nuage is compromised in absence of qin . The two groups used different alleles …