Question: Which histone modifications are associated with constitutive heterochromatin?

Context:
Remarkably, in mammalian somatic cells, H3S10P initiates in the pericentromeric heterochromatin during the late G2 phase, and phosphorylation spreads throughout the chromosomes arms in prophase, being maintained until the onset of anaphase when it gets dephosphorylated
Based on these findings, we believe that H3S10P is a good marker of pericentromeric heterochromatin, especially in the late 1- and 2-cell stages as it labels both parental genomes and that it can be used to further investigate epigenetic regulation and heterochromatin mechanisms in early preimplantation embryos
3S10 phosphorylation marks constitutive heterochromatin during interphase in early mouse embryos until the 4-cell stage
H3 trimethylation at lysine 36 is associated with constitutive and facultative heterochromatin
We show here that the maternally inherited Snurf-Snrpn 3-Mb region, which is silenced by a potent transcription repressive mechanism, is uniformly enriched in histone methylation marks usually found in constitutive heterochromatin, such as H4K20me3, H3K9me3, and H3K79me3
We show that H3K36me3 deposition within this large heterochromatin domain does not correlate with transcription events, suggesting the existence of an alternative pathway for the deposition of this histone modification
In addition, we demonstrate that H3K36me3 is markedly enriched at the level of pericentromeric heterochromatin in mouse embryonic stem cells and fibroblasts
This result indicates that H3K36me3 is associated with both facultative and constitutive heterochromatin
Our data suggest that H3K36me3 function is not restricted to actively transcribed regions only and may contribute to the composition of heterochromatin, in combination with other histone modifications.
accumulation of histone H3.3 and euchromatic histone modifications in pericentromeric heterochromatin in response to a decrease in DNA methylation levels
In this study, we show that inhibition of DNA methylation in mouse fibroblast cells affects histone modification and the subnuclear localization of histone H3.3 in a cell cycle-dependent manner
Moreover, we found that histone H3.3 was deposited on the pericentromeric heterochromatin prior to the accumulation of the euchromatic histone modifications
Classical histone modifications associated with heterochromatin, including H3K9me2, H3K27me1 and H3K27me2, were distributed throughout both A and B chromosomes
However, H3K27me2 showed a reduced level on the B chromosome compared with the A chromosomes and was not associated with some classes of constitutive heterochromatin
Recently analyzed H3K9 methyltransferases (HMTases) as SUV39H1, Clr4p, DIM-5, Su(var)3-9 or SUVH2 are responsible for the establishment of histone H3 lysine 9 methylation (H3K9me), which is intimately connected with heterochromatinization
heterochromatic histone H3K9 methyltransferases left its marks behind
Compilation and parsimony analysis reveal that histone H3K9 methylation is, next to histone deacetylation, the evolutionary most stable heterochromatic mark, which is established by at least two subfamilies of specialized heterochromatic HMTases in almost all studied eukaryote
Trimethylated H3(K9) marks pericentromeric constitutive heterochromatin and the male Y chromosome, while H2A.Z is dramatically reduced at these chromosomal locations
Of eight tested antibodies, the one for histone H4 acetylated at lysine 4, 8, 12, or 16 was best for distinguishing constitutive heterochromatin from unexpressed euchromatin, but differences in the extent of immunoprecipitation of these two types of chromatin were only modest, although highly reproducible
In addition, immunocytochemical analysis was done with an antibody to heterochromatin protein 1alpha (HP1alpha), whose preferential binding to heterochromatin has been linked to trimethylation of H3 at lysine 9
Our combined ChIP and immunocytochemical results suggest that factors other than hypoacetylation of the N-terminal tails of H4 and hypermethylation of H3 at lysine 9 can play an important role in determining whether a chromatin sequence in mammalian cells is constitutively heterochromatic
To test for the putative heterochromatinization, we quantitated chromatin immunoprecipitation with an antibody for acetylated histone H4 that discriminates between constitutive heterochromatin and unexpressed euchromatin
high methylation of H3 lysine 9 is dispensable for constitutive heterochromatin
Strong methylation at H3 lysine 4 was restricted to euchromatin, while strong methylation at H3 lysine 9 occurred preferentially in heterochromatic chromocenters of Arabidopsis nuclei

Answer: Strong methylation at H3 lysine 9 occurred preferentially in heterochromatic chromocenters of Arabidopsis nuclei. In general, heterochromatin has been linked to trimethylation of H3 at lysine 9 and parsimony analysis reveal that histone H3K9 methylation is, next to histone deacetylation, the evolutionary most stable heterochromatic mark. Classical histone modifications associated with heterochromatin also include H3K27me1 and H3K27me2. H3K36me3 function is not restricted to actively transcribed regions only and may contribute to the composition of heterochromatin. Other histone methylation marks usually found in constitutive heterochromatin are H4K20me3, H3K9me3, and H3K79me3. H3S10P is a good marker of pericentromeric heterochromatin.
H3K9 methylation
H3S10 phosphorylation
H3K79 and H4K20 methylation
Exact answer: H3K9Me1, H3K9Me2, H3K9me3, H3K9 trimethylation, H3K27me1, H3K27me2, H4K20me3, H4K20 trimethylation, H3K79me3, H3K79 methylation, H3S10, H3S10 phosphorylation