Table I.

mRNA copy number of PpENA1, PpENA2, and selected control genes in 10⁻⁹ L of cDNA

Total mRNA was extracted from either 10-d-old protonemata or 5-week-old gametophytes, quantified, adjusted to the same RNA concentration for cDNA synthesis, and used for RT-PCR.

Tissue	PpTub1	PpEF1α	PpHis-3	PpMdhar2	PpENA1a	PpENA2
Protonema	215 ± 59	312 ± 129	74 ± 11	30 ± 2	10 ± 2	1.5 ± 0.9
Gametophyte	309 ± 53	205 ± 49	127 ± 41	31 ± 2	49 ± 11	2.6 ± 1.4

^aGenes are expressed significantly different in the protonema compared to the gametophyte (n = 4; P < 0.01).