Current Knowledge on Bee Innate Immunity Based on Genomics and Transcriptomics

Abstract

As important pollinators, bees play a critical role in maintaining the balance of the ecosystem and improving the yield and quality of crops. However, in recent years, the bee population has significantly declined due to various pathogens and environmental stressors including viruses, bacteria, parasites, and increased pesticide application. The above threats trigger or suppress the innate immunity of bees, their only immune defense system, which is essential to maintaining individual health and that of the colony. In addition, bees can be divided into solitary and eusocial bees based on their life traits, and eusocial bees possess special social immunities, such as grooming behavior, which cooperate with innate immunity to maintain the health of the colony. The omics approach gives us an opportunity to recognize the distinctive innate immunity of bees. In this regard, we summarize innate bee immunity from a genomic and transcriptomic perspective. The genetic characteristics of innate immunity were revealed by the multiple genomes of bees with different kinds of sociality, including honeybees, bumblebees, wasps, leaf-cutter bees, and so on. Further substantial transcriptomic data of different tissues from diverse bees directly present the activation or suppression of immune genes under the infestation of pathogens or toxicity of pesticides.

The effect of Israeli acute paralysis virus infection on honey bee brood care behavior

“…Social immune responses are well documented in honey bees ( Apis mellifera ) and are suspected to compensate for the reduced number of immunity-related genes found in honey bees compared to other sequenced insects 5 , 10 , 11 . Hygienic behaviors, typically observed as the selective removal of dead, damaged, or diseased brood, are an effective defense against bacterial infections and have been selected for in honey bee breeding programs 12 .…”