Endogenous mammalian histone H3.3 exhibits chromatin-related functions during development

Table 1 Karyotype analysis for H3f3b wildtype (WT) and knockout (KO) mouse embryonic fibroblasts (MEFs)

	Total spreads	Normal spreads	Normal ≥ 4N	>2 defects	Chromosome fragments or breaks	Chromatid breaks	Triradial	Endo-reduplication	Rearrangements
WT1	35	26	5	0	2	0	0	0	0
WT2	35	20	10	2	0	4	0	0	0
Total WT	70	46	15	2	2	4	0	0	0
% Total		65.7%	21.4%	2.9%	2.9%	5.7%	0%	0%	0%
KO1	34	16	6	5	4	4	1	1	1
KO2	33	16	6	3	6	6	2	1	2
Total KO	67	32	12	12	10	10	3	2	3
% Total		47.8%	17.9%	17.9%	14.9%	14.9%	4%	3%	4%

Karyotype analysis done on E12.5 WT (H3f3b^WT/WT) and KO (H3f3b^Δ/Δ) MEFs (lines WT1, WT2 and KO1, KO2 respectively). Normal spreads included typical metaphase spread preparation artifacts. Typical artifacts were the loss of 1 to 2 chromosomes per spread. KO MEFs exhibited a greater incidence of abnormalities.

ISSN: 1756-8935