DOI: 10.5061/dryad.tmpg4f529
title: The more the better: Fatty acids are predictive markers of honey bee, Apis mellifera, worker longevity

description: Fatty acids (FA), stemming from nutrition, form triglycerides that are key
 components for insect energy reserves. In managed Apis mellifera
 colonies, supplementary feeding is common practice, yet micronutrients and
 microbiota (i.e. B-vitamins and probiotics) are often neglected. Given
 that B-vitamins are obligate cofactors for FA metabolism, and probiotics
 likely play key roles as well (i.e. Lactobacillus spp. synthesize
 B-vitamins), understanding how they contribute to FA acquisition remains
 unknown. Indeed, FAs are established predictors to A. mellifera longevity,
 and as such, are a logical point of interest in long-lived “winter” bees,
 where A. mellifera colony losses typically occur. Here, in a hoarding cage
 trial, freshly emerged adult winter workers were exposed to antibiotics
 (ABX) to decouple innate benefits associated to native gut microbiota, or
 left unexposed to ABX (N=72 cages, N=2088 experimental workers).
 Subsequently, all workers were fed different diets containing either
 probiotics, B-vitamins, with replicate treatments given ad libitum access
 to pollen (mimicking real-hive scenarios) or left blank (control). At the
 end of the trial, a subsample (n=356) had their total FA contents analyzed
 using Gas Chromatography coupled
 to Flame Ionization Detector (GC-FID).
 Irrespective of dietary treatment, every worker contained all 11
 identified FAs, aligning our results with a priori evidence and
 highlighting their underlying key roles for bee physiology and health. We
 show for the first time that B-vitamins alone did not improve the overall
 abundance of individual FAs (g), yet significant differences were
 associated with presence/absence of bacteria and/or access to pollen,
 reconfirming likely ties of microbiota aiding in nutrient breakdown of
 complex polysaccharides found in pollen. Finally, of clear importance,
 there was a positive significant correlation between total lipid content
 and worker longevity (+2.4 median day lifespan increase / mg of FA),
 thereby confirming the relevance of FAs for honey bee worker longevity.
description: The data here were collected at the Institue of Bee Health (Bern,
 Switzerland), in autumn 2019. Subesequent Fatty Acid (FA) analysis took
 place at the University of Fribourg (Fribourg, Switzerland). The data has
 been processed (i.e. analyzed) with the open-source software R, and the
 script and the corresponding data are available here for download. Please
 refer to the publication (materials and methods) for in-depth details
 about data collection, FA extraction, and data analysis.
description: # The more the better: Fatty acids are predictive markers of honey bee,
 Apis mellifera, worker longevity ##### Brief description of the study This
 dataset contains information from winter *Apis mellifera* worker bees,
 whom underwent a hoarding cage trial, and were subject to different
 dietary treatments. At 3 time increments, worker bees from each group were
 sampled, and processed through GC-FID to identify and quantify their fatty
 acid profiles. ##### Description of the data and file structure The
 following dataset is entitled “Brown et al Plos One 2024”, and it contains
 one tab with 31 tables of data: **Cage**: This refers to the cage that the
 experimental workers were kept in. Each cage had 26 bees/cage. **Median
 Age**: This refers to the median age for the entire treatment group.
 **Mean Age**: This refers to the mean age for the entire treatment group.
 **Day**: This refers to the sample time point from each treatment.  There
 were three total sample points: Day 7, 14, and 21. **Treatment**: This
 refers to the dietary treatment each group was assigned. **Columns 6 –
 16**: These are the raw amounts of fatty acids / bee / treatment group. 
 The name of the fatty acid is found in the column header. The values are
 expressed in nanograms [ng]. **Total Lipid Content Nano Grams**:  This
 refers to the sum of columns 6-16 (see description of columns above) in
 order to obtain a total amount of fatty acid / bee / treatment, expressed
 in nanograms. **Total Lipid Content  Grams**: This refers to the sum of
 columns 6-16 (see description of columns above) in order to obtain a total
 amount of fatty acid / bee / treatment, expressed in grams. **Ratio lipid
 to body weight**: This refers to a ratio of lipids to bodyweight, by
 simply taking the total lipid content, and dividing it by the dry weight
 of each individual bee used pre-fatty acid extraction. ##### Brief
 description of the R File This file contains all data analysis, and one
 simply needs to download the Excel file and follow the R code. **Columns
 20– 30**: These are the ratios of each fatty acid. The name of the fatty
 acid is found in the column header.  The values are expressed in ratios
 0-1. **Sum of all ratios**: This is the sum of columns 20-30, ensuring
 that the sum of all ratios = 1 (i.e. 100%).