It must be jelly, royal jelly. Giving new meaning to the adage “you are what you eat”, exciting epitranscriptomic findings have us buzzing about how diet influences larval development and royal status in honeybees.
In a process known as caste differentiation, female honeybees fed different diets become either sterile workers or fertile queens. These bees are genetically identical, with a wide range of differences in fertility, morphology, longevity, and behaviors. We’ve previously seen noble roles for microRNAs, DNA methylation, and demethylation in honeybee caste determination.
Now, thanks to Liming Wu’s lab from the Chinese Academy of Agricultural Sciences, we can add RNA modifications as an excellent opportunity for post-transcriptional regulation of gene expression after transcription. One critical, reversible, chemical modification of eukaryotic messenger RNA is N6-methyladenosine (m6A). Suspecting epitranscriptomic interference in the apiary, the regal researchers assayed transcriptome-wide m6A via m6A-seq (or MeRIP) across three stages of larval development, finding:
- Increased m6A throughout larval development
- This was also seen using liquid chromatography-tandem mass spectrometry, LC-MS/MS
- A negative correlation between gene expression and m6A methylation
- Worker larvae have more hypermethylated m6A peaks than queen larvae
- Many transcripts related to caste differentiation are differentially m6A methylated – including members of the FoxO and Wnt signaling pathways
To determine if the role of m6A was functionally relevant, the sovereign scientists chemically suppressed m6A methylation in worker larvae using 3-deazadenosine (DAA). As a result, the expression of queen-specific genes and juvenile hormone levels became more like typical queen larvae. From this work, the imperial investigators concluded that m6A methylation functionally impacts caste differentiation and larval development in the honeybee.
Don’t be jelly, go see what the buzz is all about at Cell Reports, January 2021.