Table 1. Linear mixed models of phenological variables in relation to sex and methylation at Clock poly-Q or 5′-UTR.
poly-Q | 5′-UTR | |||||||||
---|---|---|---|---|---|---|---|---|---|---|
χ21 | F | df | P | Coefficient (SE) | χ21 | F | df | P | Coefficient (SE) | |
Departure date from wintering area | ||||||||||
Year | 0.00 | 0.00a | ||||||||
Area | 0.00 | 0.00a | ||||||||
Sex | 10.79 | 1,62 | 0.002 | 0.81a | 1,61 | 0.371 | ||||
Methylation | 17.43 | 1,62 | <0.001 | 0.13a | 1,61 | 0.717 | ||||
Sex × Methylation | 10.20 | 1,62 | 0.002 | 1.54 | 1,60 | 0.219 | ||||
Males | −0.29 (0.24) | 0.57 (0.56) | ||||||||
Females | −2.15 (0.53)*** | −0.58 (0.75) | ||||||||
Arrival date to breeding site | ||||||||||
Year | 9.30** | 5.40a,* | ||||||||
Area | 3.00 | 3.70a | ||||||||
Sex | 4.38 | 1,57 | 0.041 | 2.16a | 1,57 | 0.147 | ||||
Methylation | 17.64 | 1,57 | <0.001 | 0.60a | 1,57 | 0.440 | ||||
Sex × Methylation | 3.74 | 1,57 | 0.058 | 0.00 | 1,56 | 0.997 | ||||
Males | −0.59 (0.22)** | −0.31 (0.52) | ||||||||
Females | −1.61 (0.50)** | −0.31 (0.67) | ||||||||
Breeding date | ||||||||||
Year | 7.70** | 7.70a,** | ||||||||
Area | 4.30* | 4.30a,* | ||||||||
Sex | 3.67 | 1,77 | 0.059 | 6.39a | 1,78 | 0.014 | ||||
Methylation | 4.97 | 1,77 | 0.029 | 2.65a | 1,78 | 0.108 | ||||
Sex × Methylation | 4.60 | 1,77 | 0.035 | 1.45 | 1,77 | 0.232 | ||||
Males | −0.02 (0.19) | −0.95 (0.47) | ||||||||
Females | −0.97 (0.40)* | 0.14 (0.77) |
*0.05 > P > 0.01; **0.01 ≥ P ≥ 0.001; ***P < 0.001. aEstimated from a model excluding the interaction term. χ21: likelihood ratio test for the random effect of year or area. Methylation (percentage of 5-methyl-cytosine) is included as a covariate. Year and area are included as random factors; sex as a fixed-effect factor. Sample sizes for the analyses of poly-Q were as follows (males, females): departure date from wintering area: 49, 20; arrival date to breeding site: 45, 19; breeding date: 58, 26. The corresponding values for the analyses of 5′-UTR were: 48, 19; 45, 18; 59, 25; 61, 25.