Advanced search
1 file | 867.86 KB Add to list

Evidence for faster X chromosome evolution in spiders

(2019) MOLECULAR BIOLOGY AND EVOLUTION. 36(6). p.1281-1293
Author
Organization
Abstract
In species with chromosomal sex determination, X chromosomes are predicted to evolve faster than autosomes because of positive selection on recessive alleles or weak purifying selection. We investigated X chromosome evolution in Stegodyphus spiders that differ in mating system, sex ratio, and population dynamics. We assigned scaffolds to X chromosomes and autosomes using a novel method based on flow cytometry of sperm cells and reduced representation sequencing. We estimated coding substitution patterns (dN/dS) in a subsocial outcrossing species (S. africanus) and its social inbreeding and female-biased sister species (S. mimosarum), and found evidence for faster-X evolution in both species. X chromosome-to-autosome diversity (piX/piA) ratios were estimated in multiple populations. The average piX/ piA estimates of S. africanus (0.57 [95% CI: 0.55-0.60]) was lower than the neutral expectation of 0.75, consistent with more hitchhiking events on X-linked loci and/or a lower X chromosome mutation rate, and we provide evidence in support of both. The social species S. mimosarum has a significantly higher piX/piA ratio (0.72 [95% CI: 0.65-0.79]) in agreement with its female-biased sex ratio. Stegodyphus mimosarum also have different piX/piA estimates among populations, which we interpret as evidence for recurrent founder events. Simulations show that recurrent founder events are expected to decrease the piX/piA estimates in S. mimosarum, thus underestimating the true effect of female-biased sex ratios. Finally, we found lower synonymous divergence on X chromosomes in both species, and the male-tofemale substitution ratio to be higher than 1, indicating a higher mutation rate in males.
Keywords
Genetics, Ecology, Evolution, Behavior and Systematics, Molecular Biology, sex chromosome, social spider, faster-X, female bias, ADAPTIVE PROTEIN EVOLUTION, EFFECTIVE POPULATION-SIZE, MOLECULAR EVOLUTION, SEX-CHROMOSOMES, SOCIAL SPIDER, DELETERIOUS MUTATIONS, PHYLOGENETIC ANALYSIS, PURIFYING SELECTION, GENETIC DIVERSITY, DROSOPHILA

Downloads

  • evidence for faster x chromosome evolution in spiders.pdf
    • full text (Published version)
    • |
    • open access
    • |
    • PDF
    • |
    • 867.86 KB

Citation

Please use this url to cite or link to this publication:

MLA
Bechsgaard, Jesper, et al. “Evidence for Faster X Chromosome Evolution in Spiders.” MOLECULAR BIOLOGY AND EVOLUTION, edited by Amanda Larracuente, vol. 36, no. 6, 2019, pp. 1281–93.
APA
Bechsgaard, J., Schou, M. F., Vanthournout, B., Hendrickx, F., Knudsen, B., Settepani, V., … Bilde, T. (2019). Evidence for faster X chromosome evolution in spiders. MOLECULAR BIOLOGY AND EVOLUTION, 36(6), 1281–1293.
Chicago author-date
Bechsgaard, Jesper, Mads Fristrup Schou, Bram Vanthournout, Frederik Hendrickx, Bjarne Knudsen, Virginia Settepani, Mikkel Heide Schierup, and Trine Bilde. 2019. “Evidence for Faster X Chromosome Evolution in Spiders.” Edited by Amanda Larracuente. MOLECULAR BIOLOGY AND EVOLUTION 36 (6): 1281–93.
Chicago author-date (all authors)
Bechsgaard, Jesper, Mads Fristrup Schou, Bram Vanthournout, Frederik Hendrickx, Bjarne Knudsen, Virginia Settepani, Mikkel Heide Schierup, and Trine Bilde. 2019. “Evidence for Faster X Chromosome Evolution in Spiders.” Ed by. Amanda Larracuente. MOLECULAR BIOLOGY AND EVOLUTION 36 (6): 1281–1293.
Vancouver
1.
Bechsgaard J, Schou MF, Vanthournout B, Hendrickx F, Knudsen B, Settepani V, et al. Evidence for faster X chromosome evolution in spiders. Larracuente A, editor. MOLECULAR BIOLOGY AND EVOLUTION. 2019;36(6):1281–93.
IEEE
[1]
J. Bechsgaard et al., “Evidence for faster X chromosome evolution in spiders,” MOLECULAR BIOLOGY AND EVOLUTION, vol. 36, no. 6, pp. 1281–1293, 2019.
@article{8653338,
  abstract     = {In species with chromosomal sex determination, X chromosomes are predicted to evolve faster than autosomes because of positive selection on recessive alleles or weak purifying selection. We investigated X chromosome evolution in Stegodyphus spiders that differ in mating system, sex ratio, and population dynamics. We assigned scaffolds to X chromosomes and autosomes using a novel method based on flow cytometry of sperm cells and reduced representation sequencing. We estimated coding substitution patterns (dN/dS) in a subsocial outcrossing species (S. africanus) and its social inbreeding and female-biased sister species (S. mimosarum), and found evidence for faster-X evolution in both species. X chromosome-to-autosome diversity (piX/piA) ratios were estimated in multiple populations. The average piX/ piA estimates of S. africanus (0.57 [95% CI: 0.55-0.60]) was lower than the neutral expectation of 0.75, consistent with more hitchhiking events on X-linked loci and/or a lower X chromosome mutation rate, and we provide evidence in support of both. The social species S. mimosarum has a significantly higher piX/piA ratio (0.72 [95% CI: 0.65-0.79]) in agreement with its female-biased sex ratio. Stegodyphus mimosarum also have different piX/piA estimates among populations, which we interpret as evidence for recurrent founder events. Simulations show that recurrent founder events are expected to decrease the piX/piA estimates in S. mimosarum, thus underestimating the true effect of female-biased sex ratios. Finally, we found lower synonymous divergence on X chromosomes in both species, and the male-tofemale substitution ratio to be higher than 1, indicating a higher mutation rate in males.},
  author       = {Bechsgaard, Jesper and Schou, Mads Fristrup and Vanthournout, Bram and Hendrickx, Frederik and Knudsen, Bjarne and Settepani, Virginia and Schierup, Mikkel Heide and Bilde, Trine},
  editor       = {Larracuente, Amanda},
  issn         = {0737-4038},
  journal      = {MOLECULAR BIOLOGY AND EVOLUTION},
  keywords     = {Genetics,Ecology,Evolution,Behavior and Systematics,Molecular Biology,sex chromosome,social spider,faster-X,female bias,ADAPTIVE PROTEIN EVOLUTION,EFFECTIVE POPULATION-SIZE,MOLECULAR EVOLUTION,SEX-CHROMOSOMES,SOCIAL SPIDER,DELETERIOUS MUTATIONS,PHYLOGENETIC ANALYSIS,PURIFYING SELECTION,GENETIC DIVERSITY,DROSOPHILA},
  language     = {eng},
  number       = {6},
  pages        = {1281--1293},
  title        = {Evidence for faster X chromosome evolution in spiders},
  url          = {http://dx.doi.org/10.1093/molbev/msz074},
  volume       = {36},
  year         = {2019},
}

Altmetric
View in Altmetric
Web of Science
Times cited: