. 2012 Feb 29;95(4):882–891. doi: 10.3945/ajcn.111.030783

TABLE 4.

CR lengths in E11.5 and E14.5 embryos harvested from crosses of Mthfd1^gt/+ and Mthfd1^+/+ mice fed either a control diet or FCDD or Mthfd1^gt/+ mice fed FCDD supplemented with 500 μmol hypoxanthine/L in drinking water¹

Diet	Maternal Mthfd1 genotype	Embryonic Mthfd1 genotype	CR length (E11.5)	CR length (E14.5)
Control	+/+	+/+	6.17 ± 0.24	11.14 ± 0.23
	—	gt/+	5.7 ± 0.2	11.27 ± 0.25
	gt/+	+/+	6.21 ± 0.22	11.38 ± 0.27
	—	gt/+	6.15 ± 0.33	11.35 ± 0.23
FCDD	+/+	+/+	5.81 ± 0.16	11.55 ± 0.17
	—	gt/+	5.93 ± 0.16	11.55 ± 0.23
	gt/+	+/+	5.57 ± 0.14	10.7 ± 0.35
	—	gt/+	5.67 ± 0.27	10.7 ± 0.21
FCDD + 500 μmol hypoxanthine/L	gt/+	+/+	5.25 ± 0.23	ND
	—	gt/+	4.90 ± 0.26	ND

All values are means ± SEs. n = 41–58 embryos/group. The main effects of maternal and embryonic Mthfd1 genotype and diet and relevant interactions were analyzed with the use of ANOVA with litter as a random variable. Post hoc comparisons were analyzed by Student's t test with Bonferroni correction for multiple testing. Analyses of the effects of hypoxanthine supplementation were analyzed separately in a 1-factor ANOVA that compared litters from Mthfd1^gt/+ dams fed the control diet, an FCDD, or an FCDD + hypoxanthine. ANOVA showed a trend toward a significant interaction of maternal genotype and diet on average CR length at E14.5 (F = 2.9, P = 0.09). Post hoc analysis showed that the average CR length of embryos derived from Mthfd1^gt/+ dams fed the FCDD was significantly shorter than that of embryos derived from Mthfd1^gt/+ dams fed the control diet (P = 0.05). ANOVA showed a significant effect of maternal diet on CR length (F = 5.27; P = 0.01). Post hoc analysis revealed that CR lengths in the FCDD + 500 μmol hypoxanthine/L group were significantly shorter than those in the control group (P = 0.0078) but not those in the FCDD group (P = 0.37). CR, crown-rump; E, embryonic day; FCDD, AIN93G diet deficient in folate and choline; gt, gene-trapped; ND, not determined.