TABLE 2

Quantitative PCR estimates of haploid rDNA copy number in apomictically propagated lines of Daphnia obtusa

LineGenaPlatebCTc rDNACTc GTPCTc TIFrDNA copy no. GTPdrDNA copy no. TIFdMean rDNA copy no.GTP copy no. TIFdSig. diff.e
35B16.7424.0223.971561501530.96
320A15.4422.2622.561131391261.23N
335A17.4724.3825.101201971591.64Y
355B16.4923.6223.921401721561.23Y
356B16.4123.8524.261742322031.33N
365B15.6222.8623.351512111811.40N
125B16.4423.9424.101802011911.12
1225A16.0523.6123.701892001951.06Y
1225B16.2323.8423.891962032001.03Y
1230A16.0323.8723.982282472371.08N
1230B16.1724.0224.002312272290.99N
1255A16.3023.6823.801651811731.09Y
1285A16.7123.3223.39971021001.05Y
1289A16.4623.3023.471141291221.13N
1289B16.8023.6223.501131041090.92N
295B16.7624.2424.081781601690.90
2920A15.3822.4022.321301231260.95Y
2940B15.8123.3523.271861771820.95N
2945B16.3823.9524.061902041971.08N
2960A16.0823.4523.711661981821.19N
2960B16.4824.1524.012031861950.91N
2980A15.5622.9022.941621671651.03N
305A16.6723.4923.891131491311.32
305B16.7123.7423.581311171240.89
3010A16.5323.8223.661561401480.90N
3025A16.4323.8924.131762081921.18Y
3060A16.6522.7522.836973711.06Y
3065B17.4523.2323.135551530.93N
3080B18.1924.2724.536881741.20Y
3092B17.4723.5123.766678721.19N
  • a Generation.

  • b The results are based on two experiments. Samples with the same letter were run in the same experiment (A or B). Five samples (12-25, 12-30, 12-89, 29-60, and 30-5) were run in both experiments.

  • c Threshold cycle. Each value is the mean of two replicates.

  • d Haploid copy number of the first gene listed, relative to the second gene (e.g., rDNA relative to GTP in column 7) was calculated as Embedded Image, where ΔCT is the difference in threshold cycle between the two genes.

  • e A “Y” indicates that there was at least one significant change in length variant frequencies between that generation and the previous one for which rDNA copy number was determined (e.g., between generations 20 and 35 in line 3). An “N” indicates that variant frequencies did not change significantly. Results for all time intervals in each of these four lines are shown in Figure 4.