Proteomic characterisation of the summer–winter transition in Apis mellifera

Abstract

The aim of the work presented here was to characterise the proteomic shifts that occur in worker honeybees as they transition from summer to winter. Label-free quantitative proteomic analysis was performed on the heads of Apis mellifera collected from July to October to compare the proteomes of bees as the colony progressed from summer to autumn. Analysis highlighted differential protein expression between emerged bees and hive (early and late) and forager bees, highlighting the process of age polyethism within honeybees. A shift in protein expression in bees sampled in September and October compared to those sampled in July and August was also characterised. Bees sampled in September and October had a higher abundance of proteins associated with oxidative phosphorylation and storage proteins such as hexamerin and a decreased abundance of major royal jelly proteins which could be an indication to the change that occurs in the hypopharyngeal gland in the winter bee. Results of this study indicate that bees emerging in September and October display significant proteomic differences compared to those that emerged in July and August, and that these changes may enable the bees to withstand the stresses of winter and perform their function of thermoregulation in the hive.