TABLE 1.

Complete DOT1L-KO studies.

Complete-KO strategy	H3K79me	Phenotype
Exon 5–6 LoxP (catalytic domain, SAM binding motif)	Mass Spectrometry	E8.5: Wild-type E9.5: Small, enlarged heart, stunted tail, 15% arrest, focal apoptosis, abnormal vascular morphology of the yolk sac E10:5: Developmental arrest, cardiac dilation, reduced Mendelian ratio E11.5: 100% lethality Jones et al. (2008)
Exon 13 Gene trap (nucleosome binding region)	H3K79me1/2/3 immunoblot	E9.5: Wild-type E10.5: Small, absence of red blood cells, abnormal vascular morphology of the yolk sac E11.5: Reduced Mendelian ratio E13.5: 100% lethality Feng et al. (2010)
Exon2 LoxP (out of frame)		E9.5: Retarded E10.5: Retarded E11.5: 100% lethality Liao and Szabó. (2020)
Dot1l Asn241Ala (Exon 9)	H3K79me2 immunoblot in ESCs and E10.5 embryos	E10.5: Small, normal Mendelian ratio E11.5: 10% embryos dead E13.5: 100% lethality Malcom et al. (2022)

E, embryonic day.