DNA methylation in insects

Cytosine DNA methylation has been demonstrated in numerous eukaryotic organisms and has been shown to play an important role in human disease. The function of DNA methylation has been studied extensively in vertebrates, but establishing its primary role has proved difficult and controversial. Analysing methylation in insects has indicated an apparent functional diversity that seems to argue against a strict functional conservation. To investigate this hypothesis, we here assess the data reported in four different insect species in which DNA methylation has been analysed more thoroughly: the fruit fly Drosophila melanogaster, the cabbage moth Mamestra brassicae, the peach-potato aphid Myzus persicae and the mealybug Planococcus citri

Modulation of DNA methyltransferase during the life cycle of a mealybug Planococcus lilacinus

AbstractThe levels of de novo DNA methyltransferase were studied during the development of a mealybug, Planococcus lilacinus. No enzyme activity could be detected in extracts from second instar females. But the enzyme occurs at high levels in third instar females and is maintained at that level during fourth instar when gametogenesis, fertilization and chromosome imprinting occur. These results suggest a developmental stage-specific modulation of levels of DNA methyltransferase. Assays with synthetic polymers showed that the enzyme can methylate not only polymers containing GpG but also those containing CpA and CpI