title: Intrinsic differences between males and females determine sex-specific consequences of inbreeding.
abstract: BACKGROUND
  Inbreeding increases homozygosity and exposes deleterious recessive alleles, generally decreasing the fitness of inbred individuals. Interestingly, males and females are usually affected differently by inbreeding, though the more vulnerable sex depends on the species and trait measured.
  
  
  RESULTS
  We used the soil-dwelling nematode Caenorhabditis remanei to examine sex-specific inbreeding depression across nine lineages, five levels of inbreeding, and hundreds of thousands of progeny. Female nematodes consistently suffered greater fitness losses than their male counterparts, especially at high levels of inbreeding.
  
  
  CONCLUSIONS
  These results suggest that females experience stronger selection on genes contributing to reproductive traits. Inbreeding depression in males may be further reduced by sex chromosome hemizygosity, which affects the dominance of some mutations, as well as by the absence of sexual selection. Determining the relative contributions of sex-specific expression, genes on the sex chromosomes, and the environment they are filtered through-including opportunities for sexual selection-may explain the frequent though inconsistent records of sex differences in inbreeding depression, along with their implications for conservation and the evolution of mating systems.
authors: Institute of Ecology and Evolution and Department of Biology, 5289 University of Oregon, 97403, Eugene, Oregon, USA.|Present address: Department of Biology, Stanford University, 371 Serra Mall, Stanford, CA, 94305, USA.
authors: Emily R
authors: ER
authors: Ebel
authors: Institute of Ecology and Evolution and Department of Biology, 5289 University of Oregon, 97403, Eugene, Oregon, USA. pphil@uoregon.edu.
authors: Patrick C
authors: PC
authors: Phillips
mesh_terms: D000818:Animals; D005075:Biological Evolution; D002107:Caenorhabditis / Q000235:genetics* / Q000502:physiology; D005260:Female; D006720:Homozygote; D007178:Inbreeding; D008297:Male; D052586:Mating Preference, Animal; D009154:Mutation; D012098:Reproduction / Q000235:genetics / Q000502:physiology; D012727:Sex Characteristics; D012737:Sex Factors