Table 3 Relationship between methylation of the offspring and their father and mother. Linear mixed models of methylation in the offspring at the nestling or at the adult (1-year-old) stage in relation to paternity and methylation of the father (genetic or social) and of the mother. Colony and year are included in all models as random effects. Separate models were run for paternal and maternal methylation at clock 5′-UTR because of collinearity (see Statistical analyses). The interaction term between paternity and paternal methylation was removed from the models when its effect was statistically non-significant before FDR correction. Thus, for example, the main effects on nestling cry1 are computed while excluding from the model the interaction effect, as indicated by the asterisk. The slopes of the relationships for extra-pair (EPO) and within-pair (WPO) offspring are shown and significant ones are bolded. ‘n’ values in parentheses are the number of nestlings or, respectively, 1-year-old recruits that were included in the analyses. The maternal methylation by offspring sex interaction was retained only for per2, based on statistical significance.

   Paternity

5.00

1,43

0.031

1.26

1,45

0.267

   Sex

5.73

1,43

0.021

Males: 68.0 (0.48)

Females: 67.0 (0.60)

   Paternal methylation

1.36

1,43

0.249

3.52

1,45

0.067

0.21 (0.11)

   Paternity × Paternal methylation

4.91

1,43

0.032

EPO: −0.09 (0.21)

WPO: 0.40 (0.12)^a

0.26*

1,44

0.613

EPO: 0.12 (0.23)

WPO: 0.24 (0.15)

   Sex

8.95

1,46

0.004

−1.30 (0.43)

   Maternal methylation

15.28

1,46

<0.001^†

0.53 (0.14)

0.01

1,47

0.944

0.01 (0.15)

   Paternity

13.33

1,40

<0.001

4.78

1,41

0.035

   Sex

6.06

1,41

0.018

Males: 66.7 (0.18)

Females: 67.6 (0.38)

   Paternal methylation

0.01

1,40

0.933

1.01

1,41

0.322

 0.10 (0.10)

   Maternal methylation

11.59

1,40

0.002^†

0.26 (0.08)

0.34

1,41

0.563

−0.06 (0.10)

   Paternity × Paternal methylation

13.10

1,40

<0.001^†

EPO: −0.27 (0.12)^b

WPO: 0.29 (0.10)^c

3.05*

1,40

0.088

EPO: −0.12 (0.16)

WPO: 0.24 (0.13)

   Paternity

0.18

1,35

0.676

3.67

1,36

0.063

   Paternal methylation

1.01

1,35

0.322

0.37 (0.37)

9.94

1,36

0.003^†

1.94 (0.62)

   Maternal methylation

56.99

1,35

<0.001^†

3.74 (0.49)

2.63

1,36

0.113

−1.34 (0.83)

   Paternity × Paternal methylation

0.20*

1,34

0.655

EPO: 0.72 (0.84)

WPO: 0.30 (0.41)

0.16*

1,35

0.687

EPO: 2.46 (1.44)

WPO: 1.82 (0.69)^e

   Paternity

0.92

1,38

0.345

3.06

1,38

0.088

   Sex

13.34

1,38

<0.001

14.38

1,38

<0.001

   Paternal methylation

1.95

1,38

0.171

6.34

1,38^†

0.016^†

 0.25 (0.10)

   Maternal methylation

8.74

1,38

0.005

12.65

1,38

0.001

   Sex × maternal methylation

13.37

1,38

<0.001^†

Males: −0.03 (0.08) Females: 0.58 (0.15)^d

14.20

1,38

<0.001^†

Males: −0.17 (0.10)

Females: 0.63 (0.19)^f

   Paternity × Paternal methylation

2.50*

1,37

0.122

EPO: −0.16 (0.19)

WPO: 0.18(0.09)

0.17*

1,37

0.680

EPO: 0.17 (0.24)

WPO: 0.28 (0.11)^g

   Paternity

1.68

1,42

0.202

0.00

1,43

0.970

   Paternal methylation

1.89

1,42

0.177

0.24 (0.17)

24.82

1,43

<0.001^†

1.43 (0.29)

   Maternal methylation

32.70

1,42

<0.001^†

1.01 (0.18)

1.19

1,43

0.283

0.32 (0.29)

   Paternity × Paternal methylation

2.18*

1,41

0.147

EPO: −0.23 (0.36)

WPO: 0.36 (0.19)

1.01*

1,42

0.321

EPO: 0.95 (0.56)

WPO: 1.57 (0.32)^h

   Paternity

0.18

1,14

0.674

0.09

1,14

 0.769

   Paternal methylation

0.22

1,14

0.648

0.03 (0.06)

3.45

1,14

0.084

0.13 (0.07)

   Maternal methylation

14.06

1,14

0.002^†

0.38 (0.10)

12.46

1,14

0.003^†

0.44 (0.12)

   Paternity × Paternal methylation

0.09*

1,13

0.772

EPO: 0.07 (0.13)

WPO: 0.03 (0.07)

0.02*

1,13

0.885

EPO: 0.11 (0.16)

WPO: 0.14 (0.08)