Changes in vitellogenin (Vg) and stress protein (HSP 70) in honey bee (Apis mellifera anatoliaca) groups under different diets linked with physico-chemical, antioxidant and fatty and amino acid profiles

Abstract

Simple Summary Honey bee health, longevity and colony development depend on the quantity and quality of nutrients stored in the hive. In honey bees, protein feeding modulates both individual and social immunity. The present study aimed to determine the correct feeding model by examining the changes in vitellogenin (Vg) and heat shock (HSP 70) proteins affecting honey bees' stress and overwintering ability before and after wintering. Vg levels in the hemolymph of nurse bees were higher than in forager bees in the samples taken after feeding. Increased values in amino acids and fat percentage (%) were correlated with the increased HSP 70 value in forager bees fed mixed pollen in early spring compared with the HSP 70 level in nurse bees, which gradually decreased. Therefore, nutritional quality and diversity can positively affect the health of honey bees. Honey bee colonies are often subjected to diseases, nutrition quality, temperature and other stresses depending on environmental and climatic conditions. As a result of malnutrition, the level of Vg protein decreases, leading to overwintering losses. The Vg values must be high for a successful wintering, especially before wintering. If good nutrition is not reached, the long winter period may cause an increase in colony losses. Supplementary feeding is essential for colony sustainability when floral resources are insufficient, as in recent years with the emerging climate changes. Furthermore, quality food sources or nutrients are significant for maintaining honey bee health and longevity. This study examined the changes in HSP 70 and Vg proteins in 6 groups of 48 colonies fed with five different nutrients. The fatty acids that are present in the highest amount in Cistus creticus (Pink rock-rose), Papaver somniferum (Opium poppy) and mixed pollen samples were linoleic, palmitic and cis-9-oleic acids. The highest values in proline, lysine and glutamic acid were determined in C. creticus pollen. Regarding the P. somniferum pollen, the highest values were observed in lysine, proline, glutamic and aspartic acids. The highest values in lysine, proline, leucine and aspartic acid were noticed in mixed pollen. The effect of different feeding on Vg protein in nurse and forager bee samples was higher in the mixed pollen group in the fall period. In nurse bees, the mixed pollen group was followed by Cistus creticus pollen > Papaver somniferum pollen > sugar syrup > commercial bee cake > control group, respectively (p < 0.05). In forager bees, the order was mixed pollen, P. somniferum pollen, C. creticus pollen, commercial bee cake, sugar syrup and control. In the early spring period, the Vg levels were high in the mixed pollen group in the nurse bees and the commercial bee cake group in the forager bees. In the fall period, the HSP 70 value of the forager and nurse bees was the lowest in the C. creticus group (p < 0.05). In early spring, the active period of flora, a statistical difference was found between the treatment groups.