Decoupling the effects of nutrition, age and behavioral caste on honey bee physiology and immunity

Miguel Corona; Belen Branchiccela; Shayne Madella; Yanping Chen; Jay Evans

The copyright holder for this preprint (which was not peer-reviewed) is the author/funder. . https://doi.org/10.1101/667931 doi: bioRxiv preprint 506 We analyzed the expression of five nutritionally regulated genes associated with the 507 physiological behavioral state. This group of genes include two genes (vg and mrjp1) associated 508 with nursing physiological stage independently of nutritional condition and age, and three genes 509 (mfe, ilp1 and ilp2) whose expression is associated with foraging physiological state when 510 workers are not old or nutritionally stressed. 519 However, our study is the first to investigate the effect of pollen feeding in nurse and foragers at 520 different ages at the colony level. Our finding that nutrition influences vg expression in most 521 nutritional and age groups, with the exception of older foragers, has practical implications for the 522 use of vg as a nutritional biomarker in colony-level field studies. Our expression analysis revealed 523 a trend toward higher expression levels in older nurses irrespectively of nutritional conditions. 524 Although this result was unexpected, a recent study comparing young and old nurses and foragers 525 obtained similar results both measuring mRNA and proteins levels [80] . The biological meaning 526 of this phenomenon it is unknown, however, it is interesting to note that higher levels of Vg are 527 also found in long-lived winter bees [81] . All together, these results reveal a positive association 528 between Vg and longevity, which is compatible with its antioxidant properties [29, 82] .