Figure 1. Mating in Oxytricha trifallax leads to production of a class of 27 nt RNAs.

Total RNA was purified from vegetative Oxytricha trifallax (lanes 1–4) or at various time points after mixing together complementary mating strains (lanes 5–11). In addition, total RNA was purified from strain ALXC9 treated under identical conditions as a mating for 24 hrs (lane 12 - Mock 24hr). Total RNA was phosphatase treated followed by 5′ end labeling with ³²P, separated on a 15% polyacrylamide denaturing gel and visualized using a PhosphorImager. Sizes from Decade RNA 10 nt Ladder (Ambion) are indicated at left. Positions of small RNAs of interest are indicated at right. Lanes 1–11 directly correspond to RNA preparations used to prepare libraries for Illumina sequencing listed in the same order in Table 1.