title: Co-evolutionary patterns and diversification of ant-fungus associations in the asexual fungus-farming ant Mycocepurus smithii in Panama.
abstract: Partner fidelity through vertical symbiont transmission is thought to be the primary mechanism stabilizing cooperation in the mutualism between fungus-farming (attine) ants and their cultivated fungal symbionts. An alternate or additional mechanism could be adaptive partner or symbiont choice mediating horizontal cultivar transmission or de novo domestication of free-living fungi. Using microsatellite genotyping for the attine ant Mycocepurus smithii and ITS rDNA sequencing for fungal cultivars, we provide the first detailed population genetic analysis of local ant-fungus associations to test for the relative importance of vertical vs. horizontal transmission in a single attine species. M. smithii is the only known asexual attine ant, and it is furthermore exceptional because it cultivates a far greater cultivar diversity than any other attine ant. Cultivar switching could permit the ants to re-acquire cultivars after garden loss, to purge inferior cultivars that are locally mal-adapted or that accumulated deleterious mutations under long-term asexuality. Compared to other attine ants, symbiont choice and local adaptation of ant-fungus combinations may play a more important role than partner-fidelity feedback in the co-evolutionary process of M. smithii and its fungal symbionts.
authors: Section of Integrative Biology, Patterson Laboratories, University of Texas at Austin, Austin, TX 75799, USA. antkatrina@gmail.com
authors: K
authors: K
authors: Kellner
authors: H
authors: H
authors: Fernández-Marín
authors: H D
authors: HD
authors: Ishak
authors: R
authors: R
authors: Sen
authors: T A
authors: TA
authors: Linksvayer
authors: U G
authors: UG
authors: Mueller
mesh_terms: D000818:Animals; D001000:Ants / Q000235:genetics / Q000382:microbiology / Q000502:physiology*; D005075:Biological Evolution; D004247:DNA / Q000302:isolation & purification; D005658:Fungi / Q000502:physiology*; D008969:Molecular Sequence Data; D013559:Symbiosis
chemical_list: D004247:DNA