tejas and tapas function for female germline maintenance and piRNA production in D. melanogaster

tejas (tej) and tapas (tap) are paralogues of vertebrate genes Tdrd5 and Tdrd7, respectively. Both the genes are predominantly expressed in the germline and localize to germline specific organelle, nuage . We have shown before that loss of tej function results in female sterility, probably caused by derepression of transposons. In this study we identified tap, a paralog of tej. Loss of tap function also results in mild repression of transposons in female germline and stellate in male germline but not in sterility. Loss of tej and tap function together result in loss of germline, a phenotype not observed in any single mutant, and more severe transposon derepression than both single mutants. The double mutant loss also leads to a greater reduction in piRNAs compared to that in tej mutants. The observations indicate that tej and tap function together for transposons repression via piRNA pathway and for germline maintenance.