RNA regulatory factors and 3untranslated regions (UTRs) of mRNAs play an essential role in germline life cycle. Loss of these factors results in death, sterility or germ line to soma trans-differentiation, suggesting a strict requirement for these factors to maintain the germline fate. Our goal was to understand how the RNA regulatory factors collaborate with 3UTRs to specify and maintain the germ line. We found that RNA secondary structure of the 3UTR is a major determinant of RNA target specificity.