摘要：SummaryCell-cycle quiescence is a common feature of early germline development in many animal species. InDrosophilagermline progenitors (pole cells), both G2/M and G1/S transitions are blocked. G2/M transition is repressed by maternal Nanos through suppression of Cyclin B production. However, the molecular mechanism underlying blockage of G1/S transition remains elusive. We found that repression of miR-10404 expression is required to block G1/S transition in pole cells. Expression of miR-10404, a microRNA encoded within the internal transcribed spacer 1 of rDNA, is repressed in early pole cells by maternalpolar granule component. This repression delays the degradation of maternaldacapomRNA, which encodes an inhibitor of G1/S transition. Moreover, derepression of G1/S transition in pole cells causes defects in their maintenance and their migration into the gonads. Our observations reveal the mechanism inhibiting G1/S transition in pole cells and its requirement for proper germline development.Graphical AbstractDisplay OmittedHighlights•Expression ofmir-10404encoded by rDNA region was increased inpgc−pole cells•Increased miR-10404 expression caused premature degradation of maternaldapmRNA•Premature degradation of maternaldapmRNA derepressed G1/S transition in pole cells•Derepression of G1/S transition impaired proper germline developmentCell Biology; Functional Aspects of Cell Biology; Integrative Aspects of Cell Biology
