Figure 7. Analysis of Small RNAs and DNA Elimination in the Progeny of TCD1 Knockout Cells.

(a) Accumulation of small RNA in ΔTCD1 cells. Total RNA was extracted from mating WT and ΔTCD1 cells at 0 h, 2 h, 4 h, 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h, and 24 h after mixing. RNA from approximately 5 × 10⁴ cells was fractionated in 12% acrylamide–urea gels and stained by ethidium bromide. Small RNA accumulation and disappearance was unaffected in ΔTCD1 cells. The position of the small RNA is marked by arrows. DNA oligos (38 and 24 nt) served as markers. (b) Schematic of the R element assay. Horizontal lines indicate DNA retained in the macronucleus, and filled box indicates IES. Four primers (arrows on the horizontal lines) were used for nested PCR. The lengths of the expected products are shown at the top and bottom. (c) DNA elimination is defective in the conjugated germ line Δ TCD1 cells. The product sizes of the processed MACs and unprocessed MICs are 221 bp and 1306 bp, respectively, as marked by arrows.