Table 1.

Similarities and differences in X-inactivation in marsupials.

	eutherian	marsupial	references
cis-acting ncRNA	Xist	Rsx	[64]
paternal X only or random	both	paternal X only	[65]
completeness/stability	high	variablea	[66–68]
barr body	yes	yesb
late replication of inactive X	yes	yes	[69,70]
H3/H4 hypoacetylation	yes	yes	[71]
PRC2 and H3K27me3	yes	yes	[68,72]
PRC1 and H2AK119u1	yes	nt
RNAPII depletion	yes	yes	[72]
H3K4me2 depletion	yes	yes	[72,73]
H3K9me2	yes	yes	[72]
H3K9me3	noc	yes	[72–74]
H4K20me1	yes	no	[72]
H4K20me3	no	yes	[72,73]
MacroH2A	yes	nt
CpG island methylation	yes	no	[75,76]

^aInstability observed in tissue culture cells but not in tissues.

^bDAPI dense structure observed in various studies.

^cHas been observed in some species [77].