Meeting Abstract

53.6  Saturday, Jan. 5  Evolution of selfing and the extension of lifespan PIRES DA SILVA, A*; CHAUDHURI, J.; KACHE, V.; BOSE, N; SCHROEDER, F; VON REUSS, S.; Univ. of Texas at Arlington, ; Univ. of Texas at Arlington; Univ. of Texas at Arlington; Cornell University, Ithaca; Cornell University, Ithaca; Max Planck Institute for Chemical Ecology, Jena, Germany

It has been difficult to determine the factors that affect life span in different genders because they are often genetically and morphologically different. We are studying a so far undescribed nematode that provides a useful model to study this question because it produces hermaphrodites and females that are genetically identical and have the same body size. Hermaphrodites differ from females by their ability to produce a limited amount of sperm that is used for self-fertilization. We found that the decision to become either female or hermaphrodite is plastic and environmentally determined, and that hermaphrodites live a third longer than females. A hypothesis for the evolution of different life span between genders is that females have a higher rate of extrinsic mortality caused by mating with males. We found that mating shortens life span of both females and hermaphrodites, and that the secretion of male attractants by females makes them more susceptible to extrinsic mortality. Older hermaphrodites that exhaust their self-sperm also produce sex pheromones, indicating that the longer lifespan of hermaphrodites is an adaptive trait.