-In this study, the chemical and mineral composition and trace elements in royal jelly (RJ) and worker jelly (WJ) and in royal jelly on particular days (only-2-day RJ [O2d], only-3-day RJ [O3d] and only-4-day RJ [O4d]) were determined. Significant differences in levels of moisture, protein, 10-hydroxy-2-decenoic acid (10-HDA), fructose (F) and glucose (G) were found between the RJ and WJ samples. The nutrient content was significantly higher in samples on O2d than the O3d and O4d samples. The results of this study add to the current knowledge of the nutritional value of RJ and WJ. These results also imply a strong relationship between nutritional effects and polyphenism in honey bees.chemical / composition / royal jelly / worker jelly

Is the typical zinc (Zn) content of honey and pollen sufficient to meet the nutritional requirements of honey bees? To answer this question, and find the optimal dietary Zn levels for honey bees, we investigated the effects of varying dietary Zn levels on both captive worker bees and free-flying honey bees, Apis mellifera ligustica Spinola (Hymenoptera: Apidae). We fed captive workers and free-flying honey bees with 50% (wt/wt) sucrose solutions with Zn levels of either 0, 15, 30, 45, 60, or 75 mg kg À1 diet and measured their Cu/Zn-SOD activity, the mean survival time of captive bees, the Cu/Zn-SOD activity of larvae, and the Zn concentration of royal jelly. Captive workers provided with 30 mg kg À1 dietary Zn had higher Cu/Zn-SOD activity and mean survival time than the control. Dietary Zn levels from 60 to 75 mg kg À1 significantly increased the Zn content of royal jelly provided by colonies and the Cu/Zn-SOD activity of larvae. Honey or pollen with a Zn content of <30 mg kg À1 was insufficient to satisfy the maintenance nutritional requirements of bees that were not raising larvae. It therefore seems advisable to supply supplementary Zn to non-brooding colonies when the Zn content of honey or pollen is <30 mg kg À1 . Honey or pollen with a Zn content of 60 mg kg À1 was sufficient to satisfy the nutritional requirements for royal jelly production and to improve the health of larvae. It may therefore also be advisable to provide supplementary Zn to colonies with larvae when the Zn content of honey or pollen is <60 mg kg À1 .

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UDP-glucuronosyltransferases (UGTs), being multifunctional detoxification enzymes, play a major role in the process of resistance to various pesticides in insects. However, the mechanism underlying the molecular regulation of pesticide resistance remains unclear, especially in Apis cerana cerana. In this study, all of the UGTs in Apis cerana cerana (AccUGT) have been identified through the multiple alignment and phylogenetic analysis. Expression of AccUGT genes under different pesticides, and antioxidant genes after silencing of AccUGT2B20-like, were detected by qRT-PCR. The resistance of overexpressed AccUGT2B20-like to oxidative stress was investigated by an Escherichia coli overexpression system. Also, antioxidant-related enzyme activity was detected after silencing of the AccUGT2B20-like gene. Expression pattern analysis showed that almost all UGT genes were upregulated under different pesticide treatments. This result indicated that AccUGTs participate in the detoxification process of pesticides. AccUGT2B20-like was the major gene because it was more highly induced than the others. Overexpression of AccUGT2B20-like in E. coli could effectively improve oxidative stress resistance. Specifically, silencing the AccUGT2B20-like gene increased oxidative stress by repressing the expression of oxidation-related genes, decreasing antioxidant-related enzyme activity, and increasing malondialdehyde concentration. Taken together, our results indicate that AccUGTs are involved in pesticide resistance, among which, AccUGT2B20-like contributes to the detoxification of pesticides by eliminating oxidative stress in Apis cerana cerana. This study explains the molecular basis for the resistance of bees to pesticides and provides an important safeguard for maintaining ecological balance.

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Mitogen-activated protein kinase kinases (MKKs) are important components of the MAPK signaling pathways, which play a key role in responding to stress and inflammatory stimuli. Here, a new MKK gene, AccMKK6, was identified and functionally analyzed in Apis cerana cerana. Real-time quantitative PCR (qPCR) and Western blot analysis demonstrated that the AccMKK6 expression level was up-regulated by several environmental stresses. Moreover, the knockdown of AccMKK6 by RNA interference technology altered the expression levels of some antioxidant genes. In addition, the knockdown of AccMKK6 resulted in increased malonyldialdehyde (MDA) concentration and decreased antioxidant-related enzymes activity in honeybees. To explore the MAPK signaling pathways involved in AccMKK6, we identified the transcription factor kayak in A. cerana cerana. We analyzed the interactions of AccMKK6, Accp38b, and Acckayak using the yeast two-hybrid system. AccMKK6 and Acckayak showed similar expression profiles after several stress treatments. In addition, the expression level of Acckayak was significantly increased when AccMKK6 was silenced. Therefore, we speculate that AccMKK6 may be involved in the MAPK cascades, which play a crucial role in counteracting oxidative stress caused by external stimuli.