To examine the chromatin structure of rice centromere 8, Nagaki et al. [6] used ChIP - PCR with antibodies against two different covalent modifications of the canonical H3 histone protein (rather than the centromere - specific CenH3): dimethylation on lysine 9 (dimethyl - K9), which has been shown to be enriched in heterochromatic regions, and dimethyl - K4, which is present in euchromatic portions of the chromosome. (genomebiology.biomedcentral.com)
Tachibana, M.; Sugimoto, K.; Nozaki, M.; Ueda, J.; Ohta, T.; Ohki, M.; Fukuda, M.; Takeda, N.; Niida, H.; Kato, H.; Shinkai, Y. G9a histone methyltransferase plays a dominant role in euchromatic histone H3 lysine 9 methylation and is essential for early embryogenesis. (thesgc.org)
They anticipate that the 120 Mb euchromatic genome can be completed in 5 to 7 years (depending on future funding levels). (fruitfly.org)