Author:
Adams Sally,Pathak Prachi,Kittelmann Maike,Jones Alun R. C.,Mallon Eamonn B.,Pires-daSilva Andre
Abstract
AbstractThe coexistence of different mating strategies, whereby a species can reproduce both by selfing and outcrossing, is an evolutionary enigma. Theory predicts two predominant stable mating states: outcrossing with strong inbreeding depression or selfing with weak inbreeding depression. As these two mating strategies are subject to opposing selective forces, mixed breeding systems are thought to be a rare transitory state yet can persist even after multiple speciation events. We hypothesise that if each mating strategy plays a distinctive role during some part of the species life history, opposing selective pressures could be balanced, permitting the stable co-existence of selfing and outcrossing sexual morphs. In this scenario, we would expect each morph to be specialised in their respective roles. Here we show, using behavioural, physiological and gene expression studies, that the selfing (hermaphrodite) and outcrossing (female) sexual morphs of the trioecious nematode Auanema freiburgensis have distinct adaptations optimised for their different roles during the life cycle. A. freiburgensis hermaphrodites are known to be produced under stressful conditions and are specialised for dispersal to new habitat patches. Here we show that they exhibit metabolic and intestinal changes enabling them to meet the cost of dispersal and reproduction. In contrast, A. freiburgensis females are produced in favourable conditions and facilitate rapid population growth. We found that females compensate for the lack of reproductive assurance by reallocating resources from intestinal development to mate-finding behaviour. The specialisation of each mating system for its role in the life cycle could balance opposing selective forces allowing the stable maintenance of both mating systems in A. freiburgensis.
Funder
Biotechnology and Biological Sciences Research Council
Publisher
Springer Science and Business Media LLC
Reference83 articles.
1. Darwin, C. The Effects of Cross and Self Fertilisation in the Vegetable Kingdom (D. Appleton and Company, 1877).
2. Charlesworth, D. Androdioecy and the evolution of dioecy. Biol. J. Linn Soc. 22, 333–348 (1984).
3. Charlesworth, D., Morgan, M. T. & Charlesworth, B. Inbreeding depression, genetic load, and the evolution of outcrossing rates in a multilocus system with no linkage. Evolution 44, 1469–1489 (1990).
4. Lande, R. & Schemske, D. W. The evolution of self-fertilization and inbreeding depression in plants. I. Genetic models. Evolution 39, 24–40 (1985).
5. Weeks, S. C. When males and hermaphrodites coexist: a review of androdioecy in animals. Integr. Comp. Biol. 46, 449–464 (2006).
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献