Epigenetic mechanisms regulate transcription by interacting with the DNA. They differ in many aspects such as how and where they act. Histone modifications for example are modifications at the histones in nucleosomes. DNA methylation on the other hand is a chemical modifications of the DNA base cytosine. Even though epigenetic mechanisms have been known for decades, much about their function in general and specifically in animal behavior is unknown. For 10 years the role epigenetics plays during memory formation has been investigated. For more information on this topic take a look at this publicly available review.
Epigenetics in honeybees
Honeybees (Apis mellifera) are a great model organisms for epigenetics research as they possess most epigenetic proteins described in mammals. Furthermore, their genome is sequenced and thus provides the necessary background to investigate epigenetics. Honey bees are eusocial insects, and live in hive structures with one queen and many thousands to ten thousands of workers. Queen and workers are genetically identical. Exclusively the food, the larvae are fed, determines whether they develop into queens or workers. An epigenetic mechanism – DNA methylation – plays an important role during queen/worker development.
DNA methylation is also involved in regulating memory specificity and relearning in honey bees. Furthermore, the proteins catalyzing DNA methylation (i.e. Dnmts) and demethylation (i.e. Tet) are up-regulated during the hours after olfactory learning in a specific temporal order. This temporal relationship between de novo and demethylation may proof crucial in understanding the underlying regulation. Dnmt activity in the bee’s primary olfactory center (antennal lobe) is involved in regulating changes in neural plasticity during memory formation.