Biology subjects

Shafir, S.

Publications and source records attributed to Shafir, S..

3 recordsLinked to original sources

bioRxiv2025

Nutrition of honeybees is constrained by the ratios of essential amino acids in pollen protein

Bees pollinate most of the worlds flowering plants and collect and eat floral pollen as their sole source of dietary protein, yet we know relatively little about nutritional constraints imposed on them by pollinivory. Pollen protein provides bees with essential amino acid (EAA) profiles that vary as a function of plant species, but the extent of this variation and its impact on bee feeding behaviour and performance are unknown. Here, we measured the EAA profiles of pollen, bee bread, honeybees, and royal jelly to understand natural variation in protein quality and tested how mismatches in EAAs relative to bee tissues impacted protein-to-carbohydrate regulation in adult workers. Bees fed diets with an EAA profile that matched their own tissues consumed more food, gained more weight, and ate proportionally more protein relative to carbohydrate (1:72 EAA:C) while those fed with pollen sources including bee bread ate proportionally less protein and less food overall. Deficiencies found in pollen led us to discover that nutrient balancing for protein and carbohydrate in bees was driven by the inverse relationship between quantities of the branched-chain amino acids relative to histidine in dietary protein. We predict that the creation of bee bread, a mixture of bee-collected pollen, is a general adaptation to pollen feeding that reduces the impact of imbalances in the EAA profile of pollen protein.

ecology↗

bioRxiv2025

A technical semi-field methodology to measure the effect of nutrition on honeybee brood rearing

A honeybee colonys well-being is its ability to nurture larvae into healthy adults. Understanding how nutrition supports brood rearing is crucial for developing diets that could aid against environmental threats. Nutritional research on whole colony brood development has been historically challenging due to difficulties documenting the diets impact on brood production over time. We describe a novel semi-field method to study the influence of nutrition on brood rearing using standardised small colonies formed de novo (ca. 1500 nurse-age bees and a queen) housed in adapted mating-nucs, placed inside an enclosure and limited to feeding on chemically defined diets. Complete assessments were conducted every fifteen days, assisted by a bespoke device to photograph every frame to measure cell contents. A novel metric describes the number of bees generated per gram of diet consumed, measuring the impact of nutrition on brood rearing and overall colony size.

animal behavior and cognition↗

bioRxiv2018

A transmissible RNA pathway in honey bees

One of the characteristics of RNA interference (RNAi) is systemic spread of the silencing signal among cells and tissues throughout the organism. Systemic RNAi, initiated by double-stranded RNA (dsRNA) ingestion, has been reported in diverse invertebrates, including honey bees, demonstrating environmental RNA uptake that undermines homologous gene expression. However, the question why any organism would take up RNA from the environment has remained largely unanswered. Here, we report on horizontal RNA flow among honey bees mediated by secretion and ingestion of worker and royal jelly diets. We show that ingested dsRNA spreads through the bees hemolymph associated with a protein complex. The systemic dsRNA is secreted with the jelly and delivered to larvae via ingestion. Furthermore, we demonstrate that transmission of jelly-secreted dsRNA to larvae is biologically active and triggers gene knockdown that lasts into adulthood. Finally, RNA extracted from worker and royal jellies harbor differential naturally occurring RNA populations. Some of these RNAs corresponded to honey bee protein coding genes, transposable elements, non-coding RNA and exogenous viruses. These results reveal an inherent property of honey bees to share RNA among individuals and generations. Thus, our findings suggest a transmissible RNA pathway, playing a role in social immunity and epigenetic dynamics among honey bees and potentially other closely interacting organisms.\n\nSIGNIFICANCEHoney bees are eusocial insects, living in a colony that is often described as a superorganism. RNA mobility among cells of an organism has been documented in plants and animals. Here we show that RNA spreads further in honey bees, and is horizontally transferred between individuals and across generations. We found that honey bees share biologically active RNA through secretion and ingestion of worker and royal jellies. Such RNA initiated RNA interference, which is a known defense mechanism against viral infection. Furthermore, we characterized diverse RNA profiles of worker and royal jelly, including fragmented viral RNA. Our findings demonstrate a transmissible RNA pathway with potential roles in social immunity and epigenetic signaling among members of the hive.

molecular biology↗