With spring in the air, the honeybees are already out and buzzing about and now an international team from Australia and Poland have created a different type of buzz with their research into 5hmC and its effect of bee’s behaviour.
The importance of epigenetics in bees has already been suggested with the finding that honeybees use miRNAs to enable their caste system where it creates behavioural plasticity while other research found DNA methylation creates genomic imprinting in honeybees.
In this recent study researchers investigated DNA cytosine hydroxymethylation (5hmC) in honeybees by analysing the honeybee TET orthologue. Almost all research into 5hmC has been done in mammalian systems where is has been found to be a key player in neurodevelopment, allow molecular plasticity in environmental response, and represents an alternative splicing code. This new research has found that this mark is also important in invertebrates, at least the buzzing kind.
The first research into an invertebrate TET orthologue has shown:
- Honeybee TET (AmTET) has a catalytic domain with dioxygenase activity, where it converts 5mC to 5hmC in an HEK293T cell assay.
- Switching gears from in vitro to in vivo, the team found that, just like in mammals, 5hmC is present in relatively low levels across all tissues, except for the testes and ovaries where it represents 7-10% of DNA cytosine methylation content in those specific tissues, which is comparable to levels seen in certain mammalian cells.
- AmTET is alternatively spliced and highly expressed throughout development.
- The highest expression of AmTET in the adult bee is in the brain.
At the honeybee level these findings show that 5hmC creates another layer of molecular variation that allows for additional control in multiple phenotypes of a species, where it appears to help enable the eusocial system. From a broader perspective, it also offers a novel insight for the study of TET-driven 5hmC, a molecular process related to mental health. Research was previously restricted to mammalian cell lines but now the invertebrate line has been unlocked.
Go and see what the buzz is about in Open Biology, April 2015