Abstract
The mandibular glands (MGs) of honey bee workers are key exocrine glands responsible for the biosynthesis of multiple royal jelly acids, which have important functions within the colony. However, our knowledge about the nutrition requirement of MGs is quite limited. Here, we artificially manipulated the nutritional status of caged honey bee workers (pollen and sugar candy, sugar candy only, soybean meal and sugar candy, stearic acid supplemented sugar candy or citric acid supplemented sugar candy). Then we measured their impact on the 10-hydroxy-2-decanoic acid (10-HDA) and 10-hydroxydecanoic acid (10-HDAA) content in honey bee heads to evaluate the synthesis ability of workers’ MGs, and analyzed the protein content of MGs as well as gene expression in the MGs to reveal the possible physiological changes. Our result showed that nutrition strongly impacted the MGs acid synthesis, the 10-HDA and 10-HDAA contents were significantly higher in workers fed with pollen than with sugar candy only, while an additional supply of protein and organic acid showed no significant contribution. In addition, the 10-HDA/10-HDAA ratio was also significantly affected by the nutrition status. On the contrary, different diets showed no influence on the protein content or gene expressions of MGs, except that organic acid supplements could increase the expression of key genes in fatty acid β-oxidation pathways. Taken together, our study revealed that honey bee nutritional status is closely related to the function of worker MGs. The nutritional deficiency has a significant negative impact on the synthesis ability of worker MGs, but showed no effect on the physiology of MGs.
Acknowledgements
Thanks are due to Professor Hu and Professor Zheng for assistance with the experiments and to Dr Wu and Dr Wang for writing assistance or proof reading the article.
Disclosure statement
No potential conflict of interest was reported by the authors.