. Author manuscript; available in PMC: 2020 Jan 2.

Published in final edited form as: Birth Defects Res. 2019 Sep 13;111(19):1520–1534. doi: 10.1002/bdr2.1591

TABLE 1.

Mthfd1l nullizygous mice have delayed embryonic growth and open neural tube in the cranial region

Age	Embryo genotype	No. of embryos	No. of somites (mean ± SD)	Crown to rump length (mm) (mean ± SD)	Neural tube open (no. of embryos)	Conforms to Mendelian ratio?
E8.5/E8.75	Mthfd1l^+/+	39	7.0 ± 3.4	1.15 ± 0.25	100% (39)	Yes
	Mthfd1l^z/+	71	5.7 ± 3.6	1.08 ± 0.24	100% (71)	p = .11
	Mthfd1l^z/z	23	1.6 ± 2.3*	0.68 ± 0.18*	100% (23)
E9.5	Mthfd1l^+/+	49	21.9 ± 3.1	2.39 ± 0.50	0% (0)	Yes
	Mthfd1l^z/+	74	21.8 ± 3.2	2.37 ± 0.46	4% (3)	p = .07
	Mthfd1l^z/z	29	10.5 ± 3.6*	1.46 ± 0.32*	97% (28)
E10.5	Mthfd1l^+/+	45	33.5 ± 5.7	4.07 ± 1.18	2% (1)	No
	Mthfd1l^z/+	79	32.6 ± 5.3	4.13 ± 0.84	9% (7)	p = .02
	Mthfd1l^z/z	22	23.9 ± 5.1*	2.75 ± 0.67*	68% (15)^a

Note: Embryos were dissected from a total of 78 dams at each indicated age. Numbers of somites in Mthfd1l^z/z were statistically lower compared to Mthfd1l^+/+ (p < .0001 by one-way ANOVA for each age group; asterisk indicates significant difference in Mthfd1l^z/z compared with Mthfd1l^+/+ or Mthfd1l^z/+at the p < .05 level by Bonferroni’s multiple comparison test). Number of embryos showing partially or completely open neural tube in the head were counted. Mendelian observed and expected ratios were compared the using Chi-square test.

Mutant embryos whose neural tubes had closed were small, pale, and/or having a wavy neural tube and abnormally formed heads.