Table 1.

Mammalian histone H1 variants^a

Histone H1 variants (Alt. symbols)	Mouse histone H1 genes			Human histone H1 genes			Gene Intronicb	Expression Cell typese	Expression Dependence on DNA replication	mRNA 3′UTR
	Gene name	Accession no.	Chr location	Gene name	Accession no.	Chr location
H1a (H1.1)	Hist1h1a	NM_030609	13	HIST1H1A	NM_005325	6	No	Somatic	Yes	Stem-loop
H1b (H1.5)	Hist1h1b	NM_020034	13	HIST1H1B	NM_005322	6	No	Somatic	Yes	Stem-loop
H1c (H1.2)	Hist1h1c	NM_015786	13	HIST1H1C	NM_005319	6	No	Somatic	Bothg	Bothg
H1d (H1.3)	Hist1h1d	NM_145713	13	HIST1H1D	NM_005320	6	No	Somatic	Yes	Stem-loop
H1e (H1.4)	Hist1h1e	NM_015787	13	HIST1H1E	NM_005321	6	No	Somatic	Yes	Stem-loop
H10 (H1.0, H1f0)	H1f0	NM_008197	15	H1F0	NM_005318	22	No	Somaticf, oocyte	No	Poly-A
H1x (H1.x, H1fx)	H1fx	NM_198622	6	H1FX	NM_006026	3	Y/Nc	Somatic	No	Poly-A
H1oo (H1foo)	H1foo	NM_138311	6	H1FOO	NM_153833	3	Yes	Oocytes, zygote and 2-cell embryo	No	Poly-A
H1t	Hist1h1t	NM_010377	13	HIST1H1T	NM_005323	6	No	Spermatocytes spermatids	Yes	Stem-loop
H1T2	H1fnt	NM_027304	15	H1FNT	NM_181788	12	No	Spermatids	No	Poly-A
HILS1	Hils1	NM_018792	11	HILS1	AY286318	17	Y/Nd	Spermatids	No	Poly-A

^aGene names and accession numbers are adapted from [192];

^bData derived from GenBank accessions, AceView [193] and refs. [26–29, 32, 55, 194];

^cHuman H1FX gene encodes multiple transcript variants with or without introns (see refs. [55, 193]);

^dHuman HILS1 gene consists of two exons and a small 106-bp intron and mouse Hils1 gene is intronless (ref. [27]);

^eExpression data derived from refs. [14, 22, 24–29, 39, 45, 46, 93, 194–197];

^fH1⁰ is enriched in differentiated cells (see ref. [22]);

^gThe H1c gene encodes two versions of mRNAs, polyadenylated and stem-loop forms, allowing for both replication-dependent and replication-independent expression (see ref. [36]).