Data from: The interplay of biotic and abiotic factors in shaping genetic variation at 6Pgdh in the bulb mite
Data files
Dec 29, 2025 version files 69.25 KB
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Exp_evo_main.xlsx
26.28 KB
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README.md
4.26 KB
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reproductive_success_main.xlsx
38.71 KB
Abstract
The polymorphism of 6Pgdh in the bulb mite Rhizoglyphus robini involves two alleles, S and F, which have opposing effects on male reproductive success. While S-bearing males have a reproductive advantage and the S allele fixes in the laboratory populations, polymorphism is regularly observed in natural populations. We hypothesize that the 6Pgdh polymorphism in the bulb mite may be maintained by context-dependent selection, driven by fluctuations of temperature and sexual selection intensity, as predicted by balancing selection models based on genotype-by-environment interactions. This study uses experimental evolution to track allele frequency changes over 13 generations under different temperatures (12°C and 18°C) and sexual selection intensities (equal and female-biased sex ratios). The results show a significant increase in F allele frequency under higher sexual selection intensity at 12°C. This suggests that individuals with the F allele gain reproductive advantage at lower temperatures, and 6Pgdh polymorphism may be maintained through a three-way interaction for fitness between genotype, abiotic environment (temperature), and biotic environment (sex ratio). In addition, in a direct assay of male reproductive success across temperatures, we did not detect differences between genotypes. This suggests that the allele frequency shifts observed in the experimental evolution may not be explained solely by reproductive competition, but could also involve selection acting on survival or other fitness components. The complex interplay between environmental factors and demographic dynamics in shaping allele frequencies highlights that multiple factors can interact in maintaining polymorphism, potentially through context-dependent selection.
Dataset DOI: 10.5061/dryad.crjdfn3jp
Description of the data and file structure
This dataset contains the data required to replicate the analyses presented in Unnikrishnan et al. (2025), which test the hypothesis that interactions between abiotic temperature conditions and biotic sexual selection intensity jointly shape allele frequency dynamics at the metabolic gene 6Pgdh in the bulb mite Rhizoglyphus robini.
Experimental evolution data were collected from a 13-generation experiment using a 2 × 2 factorial design, comprising two temperature regimes (12°C and 18°C) and two adult sex-ratio treatments (equal sex ratio vs. female-biased ratio). Twenty replicate populations were established (five per treatment combination), and allele frequencies at the 6Pgdh S/F polymorphism were measured at multiple evolutionary time points.
The dataset also includes results from a competitive male reproductive success assay, using the sterile-male technique, in which males of known 6Pgdh genotype competed against irradiated tester males. Assays were conducted at three temperatures (8°C, 12°C, and 24°C), and reproductive success was quantified from the proportion of fertilized eggs that hatched.
Files and variables
File: Exp_evo_main.xlsx
Description: This file contains allele frequency data from the 13-generation experimental evolution study. Twenty replicate populations (five per treatment combination across two temperatures and two sex-ratio regimes) were genotyped at multiple generations to quantify 6Pgdh genotype and allele frequencies over time.
Variables:
- Temperature: Temperature treatment at which the population was evolved (°C); values: 12, 18.
- Population: Unique population ID (1–20), corresponding to 20 independent replicate populations.
- Pop_new: Standardized population ID based only on sex-ratio treatment (1–10).
- Sex_ratio: Sex-ratio treatment of the replicate; values: "equal" (40♀:40♂) or "female-biased" (64♀:16♂).
- Generation: Generation number sampled (0, 1, 2, 7, 8, 12, 13).
- No_SS: Number of individuals genotyped as SS.
- No_FF: Number of individuals genotyped as FF.
- No_SF: Number of individuals genotyped as SF.
- No_total: Total number of individuals genotyped in that population × generation.
- SS_freq: Frequency of SS genotype (No_SS / No_total).
- FF_freq: Frequency of FF genotype (No_FF / No_total).
- SF_freq: Frequency of SF genotype (No_SF / No_total).
- S_freq: Frequency of the S allele.
- F_freq: Frequency of the F allele.
File: reproductive_success_main.xlsx
Description: This file contains data from the competitive male reproductive success assay, in which males of known 6Pgdh genotype competed against irradiated tester males at three temperatures. Reproductive success was quantified based on the fraction of transferred eggs that successfully hatched.
Variables:
- ID: Unique identifier for each male (1–542).
- temp: Temperature at which the trial was conducted (°C); values: 8, 12, 24.
- pop_ID: ID (1–4) of the experimental-evolution source population from which each male originated.
- block_id: Experimental block in which the trial occurred; values: 1 or 2.
- temp_ID: Within-temperature sequential ID for males, restarting at 1 for each temperature and block.
- eggs_trans: Number of eggs transferred to the scoring dish for hatching (maximum 20).
- eggs_hatched: Number of eggs that successfully hatched.
- m_geno: Genotype of the male; values: SS, SF, FF.
- fraction: Proportion of eggs that hatched (eggs_hatched / eggs_trans). This value represents the male’s reproductive success relative to the irradiated competitor.
Code/software
No custom code or scripts are included in this submission. The dataset consists of standard .xlsx files, which can be opened using any common spreadsheet software (e.g., Microsoft Excel, LibreOffice Calc, Google Sheets). No specialised or proprietary software is required to view or interpret the data. All variables are fully defined in the accompanying README documentation.