Abstract
A method of in situ DNA methylation with the prokaryotic methylase HpaII has been developed on fixed mitotic and meiotic chromosomes of the insect species Baetica ustulata. Incorporation of methyl groups into the chromosomal DNA is revealed by autoradiography using a labelled substrate and by its ability to prevent endonuclease digestion. The method allows direct visualization of clusters of methylatable CCGG sites. The distribution of these clusters in the chromosome complement of Baetica shows two separate domains of heterochromatic DNA which differ in their methylation patterns. Each is distributed at equivalent locations in both homologous and nonhomologous chromosomes. The existence of two compartments, one methylated and the other unmethylated, in the heterochromatic DNA could be interpreted as a remnant of the ancestral echinoderm-like pattern of methylation.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
