DOI: 10.5061/dryad.0gb5mkm9f
title: Data from: How do host age and nutrition affect density regulation of obligate versus facultative bacterial symbionts? Insights from the tsetse fly

description: Host-symbiont relationships can vary tremendously in the extent to which
 hosts depend on and control their symbionts. Obligate symbionts that
 provide micronutrients to their host are often compartmentalised to
 specialised host organs and depend on their hosts for survival, whereas
 facultative symbionts retain the ability to survive outside of their
 hosts. Few studies compare the extent to which a host controls and adjusts
 the density of obligate and facultative symbionts directly. We used tsetse
 as a model for teasing apart the relationships between a host (Glossina
 morsitans morsitans) and obligate (Wigglesworthia glossinidia) and
 facultative (Sodalis glossinidius) symbionts. We hypothesised that tsetse
 actively regulate the density of Wigglesworthia according to the host’s
 requirements, depending on their current nutritional state and
 developmental age. In contrast, we postulated that Sodalis retains some
 independence from host control, and that the growth of this symbiont is
 dependent on the conditions of the immediate environment, such as nutrient
 availability. Using qPCR, we examined how symbiont densities change across
 host age and the hunger cycle. Additionally, we investigated how host
 nutrition influences symbiont density, by comparing tsetse that were fed
 nutrient-poor or vitamin enriched diets. We found that the density of
 Wigglesworthia was not influenced by the nutritional status of the host,
 but reflected long-term host nutritional needs. In contrast, the density
 of facultative Sodalis depended on the nutrient availability. We propose
 that tsetse tightly regulate Wigglesworthia, but exert only partial
 control over Sodalis growth due to the relatively recent transition of
 this symbiont to host-associated living.
description: # Data from: How do host age and nutrition affect density regulation of
 obligate versus facultative bacterial symbionts? Insights from the tsetse
 fly
 [https://doi.org/10.5061/dryad.0gb5mkm9f](https://doi.org/10.5061/dryad.0gb5mkm9f) ## Description of the data and file structure Symbiont density data, collected by qPCR with absolute quantification, as well as survival and reproductive output of tsetse. qPCR absolute quantification data for Glossina morsitans morsitans (tsetse host), Wigglesworthia glossinidia (obligate symbiont), Sodalis glossinidius (facultative symbiont), and R code used to analyse symbiont density. empty cells are denoted "na" **Column headers for "Quantification_Cq_Results.csv" files**: * Well: plate well * Fluor: Name of the fluorescent marker * Content: Standard or Unknown * Sample: Sample ID * Cq: cq * Cq Mean: mean cq for the replicates * Cq Std. dev: standard deviation of cq * Starting Quantity (SQ): quantity of template in ng * Log starting quantity: log of the quantity of the template * SQ Mean: mean of the starting quantity * SQ Std. Dev: standard deviation of the starting quantity * Set point: Annealing temperature (degreesCelsiuss) **Column headers for "Standard_Curve_Results.csv" files**: * Fluor: Name of the fluorescent marker * Efficiency: The amplification efficiency * Slope: Gradient of the standard curve * Y-intercept: y-intercept of the standard curve * R^2: R-squared **Column headers for "Survival_reproduction.csv"**: * Date: date of record * Day: day of experiment * Columns 3 to 32: Cage number and designation for male (M), female (F), or pupae; * Count the number of surviving adults or cumulative pupae produced **Column headers for "Samples_data.csv"**: * Sample: Sample ID * Experiment: Study (nutrition, age, hunger cycle) * Plate: plate A or B for study samples that didn't fit on 1 plate * Cage: Cage ID for fly housing * Treatment: treatment * Blood_dilution: % v/v of whole blood in diet for study 3 (100% where na) * Enrichment % w/v of yeast extract in diet for study 3 (0% where na) * Hours post-meal: Time from final meal to flies being killed for study 2 * Age: Age of flies for study 1 * Sex: sex * Pregnancy: Stage of pregnancy for female flies (E = egg, L1/2/3 = larvae instar) * Wing_length: length of the hatchet wing vein in mm **Column headers for "Pupal_weight_survival.csv"**: * Deposition_date: date pupae was deposited * Deposition_day: day of experiment * Cage: Cage ID that the pupae came from * Weight: weight of pupae (in mg) once blackened * Sex: sex (recorded upon emergence) * Emergence_date: date adults emerged * Starvation_date: date emergent adults died * Survival_days: number of days emergent adults survived **Column headers for "Emergence_dates.csv**": * Cage: Cage ID * Emergence_date: date of emergence of adults from the cage * Days_after_10th: day of experiment (starting on the 10th) ## Code/software code_survival_reproduction.R: This script analyzes survival and pupae data for tsetse flies under different blood dilution and yeast extract treatments. It generates survival plots, fits statistical models to test the effects of treatment variables on pupae weight and survival, and outputs both visualizations and model summaries. code_density.R: This R script processes qPCR data to quantify symbiont (Wigglesworthia and Sodalis) densities in *Glossina* (tsetse fly) samples under different conditions (age, hunger, diet), fits statistical models to assess effects, and generates publication-ready plots of the results.