Fitness costs of symbiont switching using entomopathogenic nematodes as a model

BMC Evolutionary Biology

Brittany F. Peterson¹  Heidi Goodrich Blair²  Steven Forst³  John G. McMullen⁴  S. Patricia Stock⁴ 

[1] Center for Insect Science, University of Arizona;Current address: Department of Microbiology, University of Tennessee-Knoxville;Department of Biological Sciences, University of Wisconsin;School of Animal and Comparative Biomedical Sciences, University of Arizona;

关键词: Entomopathogenic nematodes;    Symbiosis;    Mutualism;    Partner choice;   

DOI  :  10.1186/s12862-017-0939-6

来源: DOAJ

【 摘 要 】

Abstract Background Steinernematid nematodes form obligate symbioses with bacteria from the genus Xenorhabdus. Together Steinernema nematodes and their bacterial symbionts successfully infect, kill, utilize, and exit their insect hosts. During this process the nematodes and bacteria disassociate requiring them to re-associate before emerging from the host. This interaction can be complicated when two different nematodes co-infect an insect host. Results Non-cognate nematode-bacteria pairings result in reductions for multiple measures of success, including total progeny production and virulence. Additionally, nematode infective juveniles carry fewer bacterial cells when colonized by a non-cognate symbiont. Finally, we show that Steinernema nematodes can distinguish heterospecific and some conspecific non-cognate symbionts in behavioral choice assays. Conclusions Steinernema-Xenorhabdus symbioses are tightly governed by partner recognition and fidelity. Association with non-cognates resulted in decreased fitness, virulence, and bacterial carriage of the nematode-bacterial pairings. Entomopathogenic nematodes and their bacterial symbionts are a useful, tractable, and reliable model for testing hypotheses regarding the evolution, maintenance, persistence, and fate of mutualisms.

【 授权许可】

Unknown