The University of Texas at Tyler
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Biology Research

Katrin KellnerKatrin Kellner

Title: Research associate, adjunct lecturer

Department: Biology
Building: HPR 140
Phone: (903)-566-7280



Post doc, The University of Texas at Austin, 2010-2013, Evolution of Host-symbiont relationships & Microbial Ecology

Post doc, University of Regensburg, Germany, 2009-2010, Infectious Diseases & Chemical Ecology

Doctor of Natural Sciences (German PhD equivalent), University of Regensburg, Germany, 2005-2009, Evolution, Genetics & Behavior

Diploma of Biology (German Master's equivalent), University of Regensburg, Germany, 2001-2005, Zoology, Genetics, Botany

Vordiplom (similar to undergraduate studies), University of Regensburg, Germany, 1999-2005, Biology, Chemistry, Physics

Teaching Experience

BIOL 1305 General Biology I

BIOL 1306 General Biology II

BIOL 1106 General Biology I Laboratory

BIOL 4132 Entomology Laboratory

Molecular Ecology & Evolution Laboratory Class (University of Regensburg)

Training and Supervision of individual undergraduate student's projects, two Bachelor's thesis projects and two Master's thesis projects


Research Interests

My research examines the complexity found among insect societies, especially ants.  Ants are well-suited model systems because their societies range from small aggregations of distantly related individuals to colonies composed of perfect clones.

How did complex colony life evolve? What role do mating systems play? What are the genetic backgrounds of insect colonies? What consequences have genetic structures on behavioral patterns within the colony? How can ants communicate with each other? How and why did social insect symbiosis evolve? And what role do microbes play in their association with social insects? How can dense insect societies perform disease management? These are among some of the fascinating questions I address in my research.

Although I am interested in all ants, two of my model systems are asexual species. Thelytokous reproduction (the formation of diploid females from unfertilized eggs) is known in only a handful of ant species. Platythyrea punctata is a neotropical species which shows variation in its reproductive mode throughout its distribution range, with thelytoky being found primarily in the West Indies. Mycocepurus smithii is a neotropical basal fungus-growing ant which is not only asexual but also faces the challenge of defending its monocultured fungus-gardens against garden parasites and pathogens.

While the evolution of sex represents a common theme throughout my research program, I am interested in evolutionary biology generally, and I have several research projects that range from molecular ecology, phylogeography, microbial ecology, chemical ecology, population and evolutionary genetics to the behavioral ecology of asexual and sexual ants.

To find out more about me and my research, please see my publication list at Google Scholar , Research Gate and visit my research page (


Current projects & Funding

Range limit evolution in the fungus growing ant symbiosis

A feature of host-microbe symbioses such as the fungus-gardening ants is that they can adapt to stress when selection acts on one or both partners, or on a synergistic trait emerging from the interaction. Surprisingly little empirical work has been conducted on the evolution of range-limiting mutualisms.  All fungus-gardening ants depend on the cultivation of a fungus garden, which is their only food source. Fungus gardening ants occur in the tropical and temperate zones of North- and South America, but they are absent from colder regions. Is this temperature range-limitation due to the ants, the fungus, or both of them? Many fungus-gardening ants occurring in the subtropics occupy large regions that frequently overlap different regional clines.  The Texas leafcutter ant (Atta texana) occurs all over Texas with its northernmost distributional range located near Tyler. The North American species Trachymyrmex septentrionalis occurs in the southern US (Texas, Florida) all the way up to Illinois and New York, the northernmost populations. In this project we will be cross-fostering ants and fungal cultivars from northern and southern range limits to investigate synergisms and the impact of intergenomic epistasis in these host-symbiont systems.

This international collaboration is currently funded by a grant from the National Science Foundation (DEB – 1354629) awarded to Katrin Kellner, in collaboration with Prof Ulrich Mueller at UT Austin (DEB – 1354666) and partners in Argentina, Uruguay, and Germany.

Population genetics of the Texas harvester ants, a favorite food of the Texas State Reptile (the Texas horned lizard)

Harvester ants are ecologically important ants because they consume and store vast quantities of seeds.  Dispersal also seems to be male-biased in that mating occurs near the natal nests and females disperse by walking or flying very short distances.  This project investigates the population genetics of Pogonomyrmex comanche in greater detail and perhaps explains why this species has been disappearing throughout its range in east-central Texas, southwest Arkansas and northeastern Louisiana.

This project is currently funded by a grant from Texas Ecolab ( awarded to Katrin Kellner.

Interested students are encouraged to contact me!