Table 1.

Polymerase (Pol II) phosphorylation dynamics and H3K4me2 erasure in primordial germ cells (PGCs)

Genotype	H5 staining positive, % (n/total n)	H3K4me2 positive, % (n/total n)
Wild type (N2)	7 (4/54)	0 (0/37)
mes-2 (bn11)	9 (3/35)	3 (1/40)
mes-4 (bn67)	71 (32/45)	71 (15/21)
mes-4 (bn85)	65 (15/23)	78 (29/37)

Scoring results of late stage embryos with hyperphosphorylated Pol II (H5 staining) or H3K4me2-positive PGCs. Embryos at ~1.5-f to 2-fold stage were examined within a ~40 minute developmental window at around 500 minutes postfertilization at 20°C. A strict criterion was used to assess antibody signal: only those embryos with PGCs that showed comparable levels of H5 or anti-H3K4me2 staining relative to the staining in surrounding somatic cells were scored as 'positive'.