Data and code for: A supergene controlling social structure in Alpine ants also affects the dispersal ability and fecundity of each sex
Data files
Apr 18, 2024 version files 1.12 MB
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final_mill.csv
68.94 KB
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HibernatingQueensMated.csv
35.86 KB
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male_fertility_data_final.csv
10.98 KB
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MaleSize.csv
64.87 KB
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MaleWings.csv
87.67 KB
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Mating_trials_males.csv
226.98 KB
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morphology_full_2022.csv
409.22 KB
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QueenChoiceExperiment.csv
82.91 KB
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README.md
6.42 KB
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sample_size_dispersing_supergenes.csv
125.90 KB
Abstract
Social organisation, dispersal and fecundity co-evolve, but whether they are genetically linked remains little known. Supergenes are prime candidates for coupling adaptive traits and mediating sex-specific trade-offs. Here, we test whether a supergene that controls social structure in Formica selysi also influences dispersal-related traits and fecundity within each sex. In this ant species, single-queen colonies contain only the ancestral supergene haplotype M and produce MM queens and M males, while multi-queen colonies contain the derived haplotype P and produce MP queens, PP queens, and P males. By combining multiple experiments, we show that the M haplotype induces phenotypes with higher dispersal potential and higher fecundity, for both sexes. Specifically, MM queens, MP queens, and M males are more aerodynamic and more fecund than PP queens and P males, respectively. Differences between MP and PP queens from the same colonies reveal a direct genetic effect of the supergene on dispersal-related traits and fecundity. The derived haplotype P, associated with multi-queen colonies, produces queens and males with reduced dispersal abilities and lower fecundity. More broadly, similarities between the Formica and Solenopsis systems reveal that supergenes play a major role in linking behavioural, morphological, and physiological traits associated with intraspecific social polymorphisms.
README: Dispersing Supergenes
In these files, you will find all the dataset supporting the paper "A supergene controlling social structure in Alpine ants also affects the dispersal ability and fecundity of each sex", and all scripts supporting the analyses.
Description of the data and file structure
Experiment 1:
Data for queens: morphology_full_2022.csv
Data for queens: final_mill.csv
Data for males: MaleSize.csv
Data for males: MaleWings.csv
Script: DispersingSupergenesScript_Experiment1.Rmd
Experiment 2:
Data: final_mill.csv
Script: DispersingSupergenesScript_Experiment2.Rmd
Experiment 3a:
Data: male_fertility_data_final.csv
Script: DispersingSupergenesScript_Experiment3aSperm.Rmd
Experiment 3b:
Data: QueenChoiceExperiment.csv
Script: DispersingSupergenesScript_Experiment3b.Rmd
Experiment 3c:
Data: Mating_trials_males.csv
Script: DispersingSupergenesScript_Experiment3c.Rmd
Experiment 4:
Data: HibernatingQueensMated.csv
Script: DispersingSupergenesScript_Experiment4.Rmd
Detailed Description of the data and file structure
Experiment 1:
Data for queens: morphology_full_2022.csv
Variables used:
Explanation of columns used in the analyses:
size: distance between the eyes of the queen; units = mm
mated: was the queen mated in artificial swarms or collected from her colony of origin, without placed in artificial swarms
fem_fam: colony of origin of the queen
population: population (De= high elevation population; Fi= low elevation population)
genotype: Genotype of the queen
year: year when the data was collected
Data for queens: morphology_full_2022.csv
Variables used:
weightAv: weight of the queen (fresh weight), unit = mg
colony_origin: colony of origin of the queen
Data for queens: final_mill.csv
Variables used:
load: wing loading of the queen (weight of the queen (fresh weight; unit = mg), divided by the area of her wings; unit = mm squared)
winglength_1: length of the longest wing of the queen; unit = mm
wingarea_model1: area of the longest wing of the queen; unit = mm
Data for males: MaleSize.csv
Variables used:
de: distance between the eyes of the male (size of the male); unit = mm
pop: population (De= high elevation population; Fi= low elevation population)
colony: colony of origin of the male
fmss: Genotype of the male (or queen)
sex: Sex of the individual
Data for males: MaleWings.csv
Variables used:
ss: Genotype of the male
winglength_1: length of the longest wing of the male; unit = mm
pop: population (De= high elevation population; Fi= low elevation population)
colony: colony of origin of the male
Experiment 2:
Data: final_mill.csv
Variables used:
channel: specific 'box' where the queen was tested
genotype: Genotype of the queen
trial_duration: time in seconds the queen was allowed to fly for; unit = seconds
flew: did the queen fly? y = yes, she flew
population: population (De= high elevation population; Fi= low elevation population)
weightAv: weight of the queen (fresh weight); unit = mg
weight_diff: difference in the fresh weight of the queen before and after the trial (cost of flying), calculated as weight before the trial (weightAv) - weight after the trial (weightAp); unit = mg
tot_flight.time: total time the queen spent flying; unit = in seconds
colony_origin: colony of origin of the queen
Experiment 3a:
Data: male_fertility_data_final.csv
Variables used:
male_col: colony of origin of the male
male_genotype: Genotype of the male
absolute_count: absolute number of sperm cells collected from the male (or from the queen's spermatheca); unit = number of sperm cells
de: distance between the eyes of the male (size of the male); units = mm
pop: population of origin of the male (De= high elevation population; Fi= low elevation population)
male_condition: virgin (the sperm sample came from the virgin male, otherwise = the sperm sample came from a queen's spermatheca, if 1stMating it came from a queen that mated to a virgin male, and 2ndMating, it came from a queen that mated to a previously male)
Experiment 3b:
Data: QueenChoiceExperiment.csv
Variables used:
ant: individual queen number
zonesecond: seconds the queen spent in the 'chose' area
controlorant: was the smell the control (solvent) or did it have a male's odour
condition: did the odour came from a mated or virgin male
zonetype: was the zone belonging to the odour of a P or of a M male?
volume: quantity of liquid used (same within a replicate); unit = μL
queenfullcolony: colony of origin of the queen
malefullcolony: colony of origin of the male (sample for the odour)
Experiment 3c:
Data: Mating_trials_males.csv
Variables used:
Escaped: Did the male escape? 1= the male escaped (this data was excluded)
Male_condition= was the male virgin or previously mated?
Male_sf_New= Genotype of the male
Box: Experimental box
Male_col_New: Colony of origin of the male
Population: population of origin of the male (De= high elevation population; Fi= low elevation population)
QtoM_Ratio_end: Queen to male ratio in the experimental box
Mating: Did the male mate? 1 = the male mated, 0 = the male failed to mate in the trial
Experiment 4:
Data: HibernatingQueensMated.csv
Variables used:
genotype: Genotype of the queen
fail: Did the queen fail? 1= failed, because she died or because she did not produce a brood
queen_genotype: Genotype of the queen
male_genotype: Genotype of the male with whom the queen mated
Population: population of origin of the queen (De= high elevation population; Fi= low elevation population)
fem_fam: Colony of origin of the queen
brood_size_end_experiment: Number of workers and pupae in the colony at the end of the experiment
Code/Software
the MatLab code measures wing sizes.
– *MeasureWingSize.m * is a script that generates a table for each image inside a folder.
– It requires to add inside the folder an empty .mat file called AntWingList.mat .
– Make sure the file is empty before starting the script
– The script (MeasureWingSize.m) runs on all the photos inside the current directory (MATLAB’s current folder).
– Make sure that the folder contains ONLY photos that share a reference (as the script measures Pixels that are then converted into mm by a different script (GenerateTableInMM.m).
Methods
The Alpine silver ant, F. selysi, is a socially polymorphic species occupying riverine habitats in Alpine valleys. Colony social structure is controlled by a large (13.8 Mb long, ~745 genes) and ancient (~30-million-year-old) supergene. We collected winged queens, males, and workers of F. selysi. We genotyped the social supergene of three workers per colony, to determine colony social form. We genotyped the supergene of all queens from polygyne colonies, using DNA extracted from their wings or legs. We conducted the following experiments, comparing individuals with alternate genotypes:
Experiment one: supergene’s effect on queen and male morphology
We measured the fresh weight, estimated body size (distance between eyes), wing size (length, width, perimeter, and area); and estimated wing loading (fresh weight divided by the sum of the area of her four wings) of queens, and measured the size and wings of males.
Experiment two: supergene’s effect on queen flight tendencies and abilities
We evaluated the flight propensity, flight abilities, and costs of flying (weight lost) of virgin queens of all genotypes, using a custom-made mill that automatically records flying time, speed, and distance. See also:
De Gasperin, O. 2023 Queen flying in the flight mill. figshare. https://doi.org/10.6084/m9.figshare.23932791.v1
Experiment three: supergene’s effect on male fecundity and mating success
a) We estimated the number of sperm cells produced by males and the number of sperm cells that males transfer to queens during their first and second mating event, respectively, using flow cytometry.
b) We compared MM queen’s preference for the odour of M or P males.
c) We evaluated the mating success of virgin males in experimental mating boxes, with a ratio close to 1:1 of M:P males, competing for a limiting number of MM queens, in artificial swarms.
Experiment four: supergene’s effect on queen fecundity and colony survival
We compared the survival and number of workers of 630 one-year old colonies established by queens of each supergene genotype and mated to M or P males (colonies formed by a single queen mated to a single male).