Parallel and costly changes to cellular immunity underlie the evolution of parasitoid resistance in three Drosophila species

PLoS Pathogens

Sophie Smith¹  Sarah Ommeslag¹  Francis M. Jiggins¹  Alexandre B. Leitão¹  John E. McGonigle¹  Jonathan P. Day¹ 

[1] Department of Genetics, University of Cambridge, Cambridge, United Kingdom

关键词: Hemocytes;    Drosophila melanogaster;    Larvae;    Drosophila;    Parasite evolution;    Parasitic diseases;    Parasitism;    Immune response;   

DOI  :  10.1371/journal.ppat.1006683

学科分类：生物科学（综合）

来源: Public Library of Science

【 摘 要 】

A priority for biomedical research is to understand the causes of variation in susceptibility to infection. To investigate genetic variation in a model system, we used flies collected from single populations of three different species of Drosophila and artificially selected them for resistance to the parasitoid wasp Leptopilina boulardi, and found that survival rates increased 3 to 30 fold within 6 generations. Resistance in all three species involves a large increase in the number of the circulating hemocytes that kill parasitoids. However, the different species achieve this in different ways, with D. melanogaster moving sessile hemocytes into circulation while the other species simply produce more cells. Therefore, the convergent evolution of the immune phenotype has different developmental bases. These changes are costly, as resistant populations of all three species had greatly reduced larval survival. In all three species resistance is only costly when food is in short supply, and resistance was rapidly lost from D. melanogaster populations when food is restricted. Furthermore, evolving resistance to L. boulardi resulted in cross-resistance against other parasitoids. Therefore, whether a population evolves resistance will depend on ecological conditions including food availability and the presence of different parasite species.

【 授权许可】

CC BY