Honeybees become workers or queens depending on the plant microRNAs in their diet

Plant microRNAs strongly affect gene expression


Excerpt: "Bee larvae develop into workers, in part, because their diet of pollen and honey, called beebread, is rich in plant regulatory molecules called microRNAs, which delay development and keep their ovaries inactive. Xi Chen of Nanjing University in China and colleagues, report these August 31, 2017 in PLOS Genetics.

Researchers have long known that diet plays an important role in the complex process that determines whether a honeybee larva will become a worker or a queen. While the workers primarily consume beebread, the queens feast on royal jelly secreted by the glands of nurse bees. Beebread contains much higher levels of plant microRNAs than royal jelly, so researchers decided to investigate if these molecules, which regulate gene expression in plants, could also impact honeybee caste development. They found that honeybees raised in the lab on simulated beebread supplemented with plant microRNAs developed more slowly and had a smaller body and smaller ovaries than larvae raised without the supplements. The plant microRNAs also had a similar effect on fruit fly larvae, even though fruit flies are not social insects. Further experiments showed that one of the most common plant microRNAs in beebread targets the TOR gene in honeybees, which helps determine caste.

The study shows that there is more to the story of honeybee caste formation than the traditional focus on royal jelly and identifies a previously unknown function of plant microRNAs in fine-tuning larval development."

My comment: This is an epigenetic mechanism by which an organism's gene expression is regulated by external dietary microRNAs. Plant miRNAs also act as enhancers during a process called alternative splicing. That makes it possible for a cell to produce thousands of different protein isoforms by using only one DNA strand or a combination of several DNA strands as an information library. This library is then read, copied and modified by several complex mechanisms for producing the required protein by the cell.

MicroRNAs and other non-coding RNAs from diet play a significant role in organisms' gene expression and other mechanisms involved in ecological adaptation. This is why GMO food might be surprisingly harmful for humans.

Infants are able to digest lactose in breast milk due to microRNAs originated from mammary glands. This means that miRNAs override other regulatory factors regarding lactase production.

MicroRNAs derived from diet tell us about designed regulatory factors that refute the claims about random mutations and selection. There is no such thing as mutation driven evolution. Don't get lost.