A genetic component of resistance to fungal infection in frog embryos.
The embryo has traditionally been considered to completely rely upon parental strategies to prevent threats to survival posed by predators and pathogens, such as fungi. However, recent evidence suggests that embryos may have hitherto neglected abilities to counter pathogens. Using artificial fertilization, we show that among-family variation in the number of Saprolegnia-infected eggs and embryos in the moor frog, Rana arvalis, cannot be explained by maternal effects. However, analysed as a within-females effect, sire identity had an effect on the degree of infection. Furthermore, relatively more eggs and embryos were infected when eggs were fertilized by sperm from the same, compared with a different, population. These effects were independent of variation in fertilization success. Thus, there is likely to be a significant genetic component in embryonic resistance to fungal infection in frog embryos. Early developmental stages may show more diverse defences against pathogens than has previously been acknowledged.
Sagvik
Jörgen
J
Department of Zoology, University of Gothenburg, Medicinaregatan 18, 413 90 Göteborg, Sweden. jorgen.sagvik@zool.gu.se
Uller
Tobias
T
Olsson
Mats
M
D000818:Animals; D004625:Embryo, Nonmammalian; D005260:Female; D020022:Genetic Predisposition to Disease; D007113:Immunity, Innate / Q000235:genetics; D007239:Infections / Q000235:genetics / Q000276:immunology / Q000662:veterinary*; D008297:Male; D011898:Ranidae / Q000235:genetics* / Q000276:immunology*; D044762:Saprolegnia / Q000276:immunology*; D018709:Statistics, Nonparametric