This was written by Direncan Boyraz (Izmir Institute of Technology)
1) Saccharomyces cerevisiae
Saccharomyces is one of easier organisms to be analysed for isoforms of histones and histone modifications chromatin structure studies than other complex eukaryotes; additionally Saccharomyces has common modifications with mostly all eukaryotes (1). There are some key points for this. Firstly, promoters of yeast as enhancers can be activated by becoming nucleosome-depleted. Second, nucleosomes on chromatins are well located. Distances and bordering regulatory of nucleosome provide convenience. Third, highly transcribed genes own low nucleosome occupancy because of RNA polymerase II activity with its associated factors (2).
2) Drosophila melanogaster
Fruit fly as a model organism has some advantage in chromatin structure analysis such as DNA methylation. DNA methylation in flies are manageable than other animal or models. We have available data for the system of it and also existence of less methylated genome than human genome with less number of gene is useful for epigenetic studies. More restrainable number of chromosomes form an easier environment for observations. Fruit fly is one of most model organism for those experiments. Easy observable and high similarity to human make it a good model(3).
3) Arabidopsis thaliana
Histone modification and DNA methylation are to key for studying chromatin structure and natural changes Arabidopsis lives brought it to rapid modifications evolutionary. Also epigenetic variation is proved with some ways such as modifications and the presence of repeated sequences or transposons within the promoters. First and most known plant on the earth is Arabidopsis, and this makes it a good model organism for that (4).
 Rando, Oliver J., and Howard Y. Chang. “Genome-Wide Views of Chromatin Structure.” Annual review of biochemistry 78 (2009): 245–271. PMC. Web. 28 Feb. 2018.
 Rando Lab Biochemistry and Molecular Pharmacology, Umass Medical School, Chromatin Structure and Function,
 Lyko F., Beisel C., Marhold J., Paro R. (2006) Epigenetic Regulation in Drosophila. In: Doerfler W., Böhm P. (eds) DNA Methylation: Development, Genetic Disease and Cancer. Current Topics in Microbiology and Immunology, vol 310. Springer, Berlin, Heidelberg
 Turck, F. and Coupland, G. (2014), Natural Variation in Epigenetic Gene Regulation and Its Effects on Plant Developmental Traits. Evolution, 68: 620–631. doi:10.1111/evo.12286