title: Microbiomes of ant castes implicate new microbial roles in the fungus-growing ant Trachymyrmex septentrionalis.
abstract: Fungus-growing ants employ several defenses against diseases, including disease-suppressing microbial biofilms on their integument and in fungal gardens. Here, we compare the phenology of microbiomes in natural nests of the temperate fungus-growing ant Trachymyrmex septentrionalis using culture-dependent isolations and culture-independent 16S-amplicon 454-sequencing. 454-sequencing revealed diverse actinobacteria associated with ants, including most prominently Solirubrobacter (12.2-30.9% of sequence reads), Pseudonocardia (3.5-42.0%), and Microlunatus (0.4-10.8%). Bacterial abundances remained relatively constant in monthly surveys throughout the annual active period (late winter to late summer), except Pseudonocardia abundance declined in females during the reproductive phase. Pseudonocardia species found on ants are phylogenetically different from those in gardens and soil, indicating ecological separation of these Pseudonocardia types. Because the pathogen Escovopsis is not known to infect gardens of T. septentrionalis, the ant-associated microbes do not seem to function in Escovopsis suppression, but could protect against ant diseases, help in nest sanitation, or serve unknown functions.
authors.affiliation: Section of Integrative Biology, 1 University Station (C0930), University of Texas at Austin, Austin, TX 78712, USA. heatherishak@gmail.com
authors.forename: Heather D
authors.initials: HD
authors.lastname: Ishak
authors.forename: Jessica L
authors.initials: JL
authors.lastname: Miller
authors.forename: Ruchira
authors.initials: R
authors.lastname: Sen
authors.forename: Scot E
authors.initials: SE
authors.lastname: Dowd
authors.forename: Eli
authors.initials: E
authors.lastname: Meyer
authors.forename: Ulrich G
authors.initials: UG
authors.lastname: Mueller
mesh_terms: D000818:Animals; D001000:Ants / Q000382:microbiology* / Q000502:physiology*; D044822:Biodiversity; D019295:Computational Biology; D005260:Female; D008297:Male; D054892:Metagenome; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012621:Seasons; D017422:Sequence Analysis, DNA; D013559:Symbiosis / Q000235:genetics
chemical_list: D012336:RNA, Ribosomal, 16S