title: Increased exposure to acute thermal stress is associated with a non-linear increase in recombination frequency and an independent linear decrease in fitness in Drosophila.
abstract: BACKGROUND
  Meiotic recombination rate has long been known to be phenotypically plastic. How plastic recombination evolves and is maintained remains controversial; though a leading model for the evolution of plastic recombination rests on the tenet that organismal fitness and recombination frequency are negatively correlated. Motivated by the mounting evidence that meiotic recombination frequencies increase in response to stress, here we test for a negative correlation between fitness and recombination frequency. Specifically, the fitness-associated recombination model (FAR) predicts that if stress increases meiotic recombination frequency, then increasing exposure to stressful conditions will yield an increasing magnitude of the recombinational response, while concomitantly decreasing fitness.
  
  
  RESULTS
  We use heat shock as a stressor to test this prediction in Drosophila melanogaster. We find that increased exposure to heat shock conditions is associated with a non-linear increase in meiotic recombination frequency. We also find an independent effect of heat shock on organismal fitness, with fitness decreasing with increased duration of thermal stress.
  
  
  CONCLUSIONS
  Our results thus support the foundation of the FAR model for the evolution of plastic recombination. Our data also suggest that modulating recombination frequency is one mechanism by which organisms can rapidly respond to environmental cues and confer increased adaptive potential to their offspring.
authors: Department of Biological Sciences, North Carolina State University, Campus Box 7614, Raleigh, NC, 27695, USA. savannah_jackson@med.unc.edu.
authors: Savannah
authors: S
authors: Jackson
authors: Department of Biological Sciences, North Carolina State University, Campus Box 7614, Raleigh, NC, 27695, USA. dahlia@statgen.ncsu.edu.|Bioinformatics Research Center, North Carolina State University, Raleigh, USA. dahlia@statgen.ncsu.edu.
authors: Dahlia M
authors: DM
authors: Nielsen
authors: Department of Biological Sciences, North Carolina State University, Campus Box 7614, Raleigh, NC, 27695, USA. ndsingh@ncsu.edu.|Bioinformatics Research Center, North Carolina State University, Raleigh, USA. ndsingh@ncsu.edu.
authors: Nadia D
authors: ND
authors: Singh
mesh_terms: D000818:Animals; D005075:Biological Evolution; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000502:physiology*; D018869:Heat-Shock Response; D008540:Meiosis; D011995:Recombination, Genetic