TABLE 2.

			% P-Ser5				% P-Ser2
Transgene	% lethality	N	None	Low	High	N	None	Positive	N
PIE-1(1–335)	9	701	0	100	0	15	87	13	105
PIE-1(1–355) cdk-7(RNAi)	96	422	100	0	0	42	100	0	42
PIE-1(1–335) cit-1.1/1.2(RNAi)	91	408	4	96	0	51	100	0	40
PIE-1(1–335) ama-1(RNAi)	97	445	100	0	0	51	100	0	45
PIE-1(1–240)	100	1038	0	0	100	25	0	100	151
PIE-1(1–240) cdk-7(RNAi)	100	441	100	0	0	46	100	0	45
PIE-1(1–240) cit-1.1/1.2(RNAi)	100	446	0	0	100	44	100	0	29
PIE-1(1–240) ama-1(RNAi)	100	364	100	0	0	45	100	0	43

Control RNAi experiments to evaluate the specificity of the P-Ser5 and P-Ser2 signals in pie-1(zu127) embryos carrying the indicated transgenes. P-Ser5 levels are divided into three categories depending on whether P-Ser5 was detected at levels equivalent to that seen in somatic blastomeres (high), at the intermediate level typical of wild-type germline blastomeres (low, with two prominent foci), or absent (none) (also see Figure 2). As expected for a modification linked to initiation, P-Ser5 signals (both in the high and low categories) are eliminated upon depletion of cdk-7 and ama-1, but remain unaffected by depletion cit-1.1/1.2. In contrast, as expected for a modification linked to elongation, P-Ser2 signals are eliminated upon depletion of all three genes.