Genome-wide regulatory deterioration impedes adaptive responses to stress in inbred populations of Drosophila melanogaster: inbreeding under stress assessed by RNAseq

Research output: Contribution to journalArticle


Inbreeding depression is often intensified under environmental stress (i.e., inbreeding–stress interaction). Although the fitness
consequences of this phenomenon are well-described, underlying mechanisms such as an increased expression of deleterious alleles
under stress, or a lower capacity for adaptive responses to stress with inbreeding, have rarely been investigated. We investigated a
fitness component (egg-to-adult viability) and gene-expression patterns using RNA-seq analyses in noninbred control lines and in
inbred lines of Drosophila melanogaster exposed to benign temperature or heat stress. We find little support for an increase in the
cumulative expression of deleterious alleles under stress. Instead, inbred individuals had a reduced ability to induce an adaptive
gene regulatory stress response compared to controls. The decrease in egg-to-adult viability due to stress was most pronounced in
the lines with the largest deviation in the adaptive stress response (R
= 0.48). Thus, we find strong evidence for a lower capacity
of inbred individuals to respond by gene regulation to stress and that this is the main driver of inbreeding-stress interactions. In
comparison, the altered gene expression due to inbreeding at benign temperature showed no correlation with fitness and was
pronounced in genomic regions experiencing the highest increase in homozygosity.


  • Mads F. Schou
  • Jesper Bechsgaard
  • Joaquin Muñoz
  • Torsten N. Kristensen
External organisations
  • Aarhus University
  • Aalborg University
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Genetics


  • Inbreeding depression, inbreeding–stress interactions, small populations
Original languageEnglish
Pages (from-to)1614-1628
Issue number8
Publication statusPublished - 2018 Aug 1
Publication categoryResearch
Externally publishedYes