Current Research

I manage the on-going genetic research for Dr. Ulrich Mueller in the Integrative Biology Department at The University of Texas at Austin.   This lab works on fungus-growing ants and their symbiotic fungi.  This system is exceedingly complex with other players such as parasitic fungi (Escovopsis), bacteria (Pseudonocardia, Kribbella, Amycolatopsis, Streptomyces), and yeasts.

We are focusing on symbiont-choice type studies to see if ants can detect their own fungi from others using microsatellite genotyping.  We are also investigating the bacteria and fungi interactions in local and lab colonies using DNA sequencing and 454 pyro-sequencing technology.

We are also collaborating on projects with the fire ant lab at the Brakenridge Field Laboratory.

Publications:

Ishak, HD, Miller, JL, Sen, R, Dowd, SE, Meyer, E, and UG Mueller.  2011. Microbiomes of ant castes implicate new microbial roles in the fungus-growing ant Trachymyrmex septentrionalis.  Scientific Reports  doi:10.1038/srep00204

Rabeling, CR, Gonzales, O, Schultz, T, Bacci, M Jr, Garcia, M, Verhaagh, M, Ishak, HD, and UG Mueller. 2011. Cryptic sexual populations account for genetic diversity and ecological success in a widely distributed, parthenogenetic fungus-growing ant.  PNAS  doi: 10.1073/pnas.1105467108

Rodrigues, A, Mueller, UG, Ishak, HD, Bacci, M Jr, and FC Pagnocca. 2011. Ecology of microfungal communities in gardens of fungus-growing ants (Hymenoptera: Formicidae): A year-long survey of three species of attine ants in Central Texas. FEMS Microbiology Ecology.  DOI: 10.1111/j.1574-6941.2011.01152.x

Mueller, UG, Mikheyev, AS, Hong, E, Sen, R, Warren, DL, Solomon, SE, Ishak, HD, Cooper, M, Miller, JL, Shaffer, KA, and TE Juenger. 2011. Evolution of cold-tolerant fungal symbionts permits winter fungiculture by leafcutter ants at the northern frontier of tropical ant-fungus symbiosis.  PNAS doi:10.1073/pnas.1015806108

Ishak, HD, Plowes, R, Sen, R, Kellner, K, Meyer, E, Estrada, DA, Dowd, SE, and UG Mueller. 2011. Bacterial diversity in Solenopsis invicta and Solenopsis geminata ant colonies characterized by 16S amplicon 454 pyrosequencing. Microbial Ecology DOI: 10.1007/s00248-010-9793-4

Choo, J, Ishak, HD, Juenger, TE, Mueller, U, and BB Simpson. 2010. Characterization of 14 microsatellite loci in a tropical palm Attalea phalerata (Arecaceae). American Journal of Botany doi:10.3732/ajb.1000281

Mueller, UG, Scott, JJ, Ishak, HD, Cooper, M, Rodrigues, A. 2010. Monoculture of Leafcutter Ant Gardens. PLoS One. http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0012668

Sen, R, Ishak, HD, Kniffin, TR, and UG Mueller. 2010. Construction of chimaeric gardens through fungal intercropping: a symbiont choice experiment in the leafcutter ant Atta texana (Attini, Formicidae). Behavioral Ecology and Sociobiology 64: 1125-1133. DOI: 10.1007/s00265-010-0928-x.

Mueller, UG, Ishak, HD, Lee, JC, Sen, R and RR Gutell. 2010. Placement of attine ant-associated Pseudonocardia in a global Pseudonocardia phylogeny (Pseudocardiaceae, Actinomycetales): a test of two symbiont-association models.  Antonie van Leeuwenhoek. DOI 10.1007/s104082-010-9427-3.

Sen, R, Ishak, HD, Estrada, D, Dowd, SE, Hong, E, and UG Mueller. 2009. Generalized antifungal activity and 454-screening of Pseudonocardia and Amycolatopsis bacteria in nests of fungus-growing ants. PNAS 2009 106: 17805-17810

Commentary for PNAS publication : Boomsma, J.J., and D. K. Aanen. 2009. Rethinking crop-disease management in fungus-growing ants.  PNAS 2009 106:17611-17612

Filed under Uncategorized | Comments Off