Phytochemical Helps Differentiate Workers from Queen Bees

The consumption of p-coumaric acid, a chemical found in honey and pollen, may help set a female honeybee on its course to becoming a worker instead of a queen.

Aug 28, 2015
Ashley P. Taylor

WIKIMEDIA, QUARTLA newly hatched female honeybee larva can develop into either an egg-laying queen or a sterile worker. One determinant of a female bee’s social caste, it turns out, is the insect’s early-life diet. Future queens are fed nothing but royal jelly, a glandular secretion of so-called nurse bees, which feed both the larvae and the queen; queens continue this exclusive royal jelly diet throughout their lives. Future worker bees, on the other hand, are only fed royal jelly for their first three days; after that, they eat royal jelly mixed with fermented pollen, called beebread, and honey. Precisely what about these honeybee baby foods might help determine their developmental fates has long been an open question.

Consumption of the phytochemical p-coumaric acid, a phenolic substance found in beebread and honey but not in royal jelly, may be one factor that leads female larvae to become worker bees, according to a study published today (August 28) in Science Advances. Researchers from the University of Illinois at Urbana-Champaign “show that p-coumaric acid is a potent regulator of gene regulation and development in honey bees,” Ryszard Maleszka, who studies genetics and epigenetics in honeybees at the Australian National University in Canberra but was not involved in the work wrote in email to The Scientist. This chemical, he continued, “has the capacity to suppress ovary development and it affects the expression of genes including those controlling organ sizes, epigenetic machineries and detoxification.”

“The authors clearly show that p-coumaric acid represses genes that have been found in other studies to be associated with queen development,” Peter Dearden, a geneticist and bee researcher at the University of Otago in Dunedin, New Zealand, who also was not involved in the work, wrote in an email. “Current models of caste development in bees rest on the idea that royal jelly contains a substance or substances that trigger, or enhance queen development. The development of different castes then rests on differential feeding of royal jelly.”

“This paper doesn’t directly challenge this model,” Dearden noted, “but shows that a component of the diet which is excluded from royal jelly represses genes involved in queen development.”

The researchers happened upon their results indirectly, said lead author May Berenbaum. The present study began as a follow-up to a 2013 study, in which Berenbaum’s lab found that p-coumaric acid strongly activated genes involved in detoxification and immunity in adult worker bees. So the researchers wondered whether the chemical might also upregulate detoxification genes in larvae.

To find out, they raised two groups of larvae: one on a standard bee diet—royal jelly plus extra sugars and yeast extract—and another on the same diet plus p-coumaric acid. After three days, Berenbaum and her colleagues isolated RNA from the larvae, sequenced it, and then compared gene expression between the two larval groups.

In the larvae fed p-coumaric acid, Berenbaum said, “we saw a whole bunch of detoxification genes upregulated, even more immunity genes upregulated, and then—which was a surprise to us—a whole bunch of genes which were previously shown to be involved in caste determination. . . . In retrospect, it made a lot of sense.”

Polymers of p-coumaric acid are the main compound of pollen-grain walls, and p-coumaric acid monomers are released when the pollen is fermented into beebread. Also found in honey, the phytochemical is “in almost every bite that a bee eats—except for queens and queen-destined larvae,” said Berenbaum.

Considering the data suggesting p-coumaric acid might repress queen development, the researchers next raised two groups of larvae on a diet of royalactin—the main protein in royal jelly (and a standard diet for in vitro queen-rearing)—with or without the addition of p-coumaric acid. This time, they let the bees develop through the larval and pupal stages until the bees emerged as young adults. The researchers then compared ovarian development between the two groups. Bees exposed to p-coumaric acid during developed had smaller ovaries than those reared without the phytochemical.

The result supports the idea that consumption of p-coumaric acid, along with other phenolic compounds found in honey and beebread, leads to “a form of chemical castration” of future worker bees, the authors wrote in their report. But p-coumaric acid is probably only part of the caste-determination story, Berenbaum added.

“Royal jelly is important for producing queens,” she said, “but, apparently, plant products are important for producing workers.”

W. Mao et al., “A dietary phytochemical alters caste-associated gene expression in honey bees,” Science Advances, 2015.

January 2019

Cannabis on Board

Research suggests ill effects of cannabinoids in the womb


Sponsored Product Updates

FORMULATRIX® digital PCR technology to be acquired by QIAGEN
FORMULATRIX® digital PCR technology to be acquired by QIAGEN
FORMULATRIX has announced that their digital PCR assets, including the CONSTELLATION® series of instruments, is being acquired by QIAGEN N.V. (NYSE: QGEN, Frankfurt Stock Exchange: QIA) for up to $260 million ($125 million upfront payment and $135 million of milestones).  QIAGEN has announced plans for a global launch in 2020 of a new series of digital PCR platforms that utilize the advanced dPCR technology developed by FORMULATRIX combined with QIAGEN’s expertise in assay development and automation.
Application of CRISPR/Cas to the Generation of Genetically Engineered Mice
Application of CRISPR/Cas to the Generation of Genetically Engineered Mice
With this application note from Taconic, learn about the power that the CRISPR/Cas system has to revolutionize the field of custom mouse model generation!
Translational Models of Obesity, Dysmetabolism, Diabetes, and Complications
Translational Models of Obesity, Dysmetabolism, Diabetes, and Complications
This webinar, from Crown Bioscience, presents a unique continuum of translational dysmetabolic platforms that more closely mimic human disease. Learn about using next-generation rodent and spontaneously diabetic non-human primate models to accurately model human-relevant disease progression and complications related to obesity and diabetes here!
BiochemAR: an augmented reality app for easy visualization of virtual 3D molecular models
BiochemAR: an augmented reality app for easy visualization of virtual 3D molecular models
Have you played Pokemon Go? Then you've used Augmented Reality (AR) technology! AR technology holds substantial promise and potential for providing a low-cost, easy to use digital platform for the manipulation of virtual 3D objects, including 3D models of biological macromolecules.