Katrin Kellner

• Dr rer nat
• Professor (Associate) at The University of Texas at Tyler

One of the few imperiled ant species in North America is the Comanche Harvester Ant, Pogonomyrmex comanche. Despite its status, little is known about its natural history throughout its range in the western Gulf Coastal Plain of North America. This study presents a regional phylogeographic analysis of P. comanche across sites in its natural range as...

One of the few endangered ant species in North America is the Comanche Harvester Ant, Pogonomyrmex comanche . Despite its status, there is little known about its natural history throughout its range in the western Gulf Coastal Plain of North America. This study presents a regional phylogeographic analysis of P. comanche across sites in central and...

Advances in our understanding of symbiotic stability have demonstrated that microorganisms are key to understanding the homeostasis of obligate symbioses. Fungus-gardening ants are excellent model systems for exploring how microorganisms may be involved in symbiotic homeostasis as the host and symbionts are macroscopic and can be easily experimenta...

Advances in our understanding of symbiotic stability have demonstrated that microorganisms are key to understanding the homeostasis of obligate symbioses. Fungus-gardening ants are excellent model systems for exploring how microorganisms may be involved in symbiotic homeostasis as the host and symbionts are macroscopic and can be easily experimenta...

Nestmate acceptance in ants can depend on environmental factors (e.g., odors acquired from environment) or on ant genotype. Here, we test whether queen acceptance by workers of the fungus-farming ant Mycocepurus smithii can be predicted from the fungal genotypes of fungus gardens and from the ant genotypes of interacting workers and queens. Mycocep...

The fungus gardening-ant system is considered a complex, multi-tiered symbiosis, as it is composed of ants, their fungus, and microorganisms associated with either ants or fungus. We examine the bacterial microbiome of Trachymyrmex septentrionalis and Mycetomoellerius turrifex ants and their symbiotic fungus gardens, using 16S rRNA Illumina sequenc...

In North America, freshwater unionids are one of the most endangered taxa and have been historically poorly studied. Of Texas unionid species, 65% of them to are considered rare by state and federal agencies. Focused research and conservation efforts are especially necessary in aquatic habitats in order to sustain mussel populations. This study foc...

Symbionts can have profound effects on host fitness, adaptations and range distributions. Stress‐induced evolution is difficult to show in obligate symbioses; however, adaptive evolution within an obligate symbiosis can be investigated experimentally or by correlating trait variation with stress along an ecological cline (i.e. temperature‐stress gr...

The fungus gardening-ant system is considered a complex, multi-tiered symbiosis, as it is composed of ants, their fungus, and microorganisms associated with either ants or fungus. We examine the bacterial microbiome of Trachymyrmex septentrionalis and Mycetomoellerius turrifex ants and their symbiotic fungus gardens, using 16S rRNA Illumina sequenc...

Over the past few decades, large-scale phylogenetic analyses of fungus-gardening ants and their symbiotic fungi have depicted strong concordance among major clades of ants and their symbiotic fungi, yet within clades, fungus sharing is widespread among unrelated ant lineages. Sharing has been explained using a diffuse coevolution model within major...

Over the past few decades, large-scale phylogenetic analyses of fungus-gardening ants and their symbiotic fungi have depicted strong concordance among major clades of ants and their symbiotic fungi, yet within clades, fungus sharing is somewhat widespread among unrelated ant lineages. These symbioses are thought to be explained by a diffuse coevolu...

For nearly all organisms, dispersal is a fundamental life‐history trait that can shape their ecology and evolution. Variation in dispersal capabilities within a species exists and can influence population genetic structure and ecological interactions. In fungus‐gardening (attine) ants, co‐dispersal of ants and mutualistic fungi is crucial to the su...

Objective: The objective of this study is to develop and identify polymorphic microsatellite markers for fungus-gardening (attine) ants in the genus Trachymyrmex sensu lato. These ants are important ecosystem engineers and have been a model group for understanding complex symbiotic systems, but very little is understood about the intraspecific gen...

Introduction The Florida Harvester ant, P. badius, is an important seed disperser, which collects more than 58 plant species in longleaf pine and turkey oak woodlands across the Southeastern Coastal Plain of the United States. 1 Mature colonies store up to half a kilogram (>300,000) living seeds in subterranean chambers, so called granaries. 2,3 Co...

Objective The objective of this study is to develop and identify polymorphic microsatellite markers for fungus-gardening (attine) ants in the genus Trachymyrmex sensu lato . These ants are important ecosystem engineers and have been a model group for understanding complex symbiotic systems, but very little is understood about the intraspecific gene...

Objective The objective of this study is to develop and identify polymorphic microsatellite markers for fungus-gardening (attine) ants in the genus Trachymyrmex sensu lato . These ants are important ecosystem engineers and have been a model group for understanding complex symbiotic systems, but very little is understood about the intraspecific gene...

Ants are among the most successful insects in Earth's evolutionary history. However, there is a lack of knowledge regarding range-limiting factors that may influence their distribution. The goal of this study was to describe the environmental factors (climate and soil types) that likely impact the ranges of five out of the eight most abundant Trach...

Lower diversity at range margins of expanding populations is thought to reduce host-symbiont speci-ficity of obligate symbioses. Selection for relaxed symbiont recognition systems is thought to occur when most, if not all, symbionts available to a host are genetically similar. This study evaluated whether the genetic diversity of symbiont populatio...

To explore landscape genomics at the range limit of an obligate mutualism, we use genotyping‐by‐sequencing (ddRADseq) to quantify population structure and the effect of host–symbiont interactions between the northernmost fungus‐farming leafcutter ant Atta texana and its two main types of cultivated fungus. Genome‐wide differentiation between ants a...

To explore landscape genomics at the range limit of an obligate mutualism, we used genotyping-by-sequencing (ddRADseq) to quantify population structure and the effect of hostsymbiont interactions between the northernmost fungus-farming leafcutter ant Atta texana and its two main types of cultivated fungus. At local scales, genome-wide differentiati...

Group-living can promote the evolution of adaptive strategies to prevent and control disease. Fungus-gardening ants must cope with two sets of pathogens, those that afflict the ants themselves and those of their symbiotic fungal gardens. While much research has demonstrated the impact of specialized fungal pathogens that infect ant fungus gardens,...

Pogonomyrmex comanche is a species of harvester ant found within the fine-grain sandy soils of Texas, Oklahoma, Arkansas, and Louisiana. They are thought to be the favorite food of the Texas Horned Lizard and because of this, their conservation is of high importance. This study aims to understand and identify their life histories to hopefully compo...

Modeling Symbioses In this study, we investigated the species distributions of eight Trachymyrmex species; we were interested in determining which environmental variables had the biggest impact on distribution. These species form an obligate symbiosis with their fungal cultivars; one individual cannot live without the other. The fungal-gardens have...

Darwin famously described special difficulties in explaining social evolution in insects. More than a century later, the evolution of sociality - defined broadly as cooperative group living - remains one of the most intriguing problems in biology. Providing a unique perspective on the study of social evolution, this volume synthesizes the features...

Fungus-farming ants (Hymenoptera: Formicidae, Attini) exhibit some of the most complex microbial symbioses because both macroscopic partners (ants and fungus) are associated with a rich community of microorganisms. The ant and fungal microbiomes are thought to serve important beneficial nutritional and defensive roles in these symbioses. While most...

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 do...

Lactobacilli (Lactobacillales: Lactobacillaceae) are well known for their roles in food fermentation, as probiotics, and in human health, but they can also be dominant members of the microbiotae of some species of Hymenoptera (ants, bees, and wasps). Honey- and bumble-bees associate with host-specific lactobacilli, and some evidence suggests that t...

Geographic parthenogenesis is a distribution pattern, in which parthenogenetic populations tend to live in marginal habitats, at higher latitudes and altitudes and island-like habitats compared with the sexual forms. The facultatively parthenogenetic ant Platythyrea punctata is thought to exhibit this general pattern throughout its wide range in Ce...

Mutualistic/Beneficial bacteria of insects play important roles in nutritional ecology and defense against parasites and disease. The mechanisms how insects acquire these symbionts have not been studied in detail. Bacterial symbionts can be inherited from parent to offspring generation (vertical symbiont transmission), leading potentially to host-s...

Insect societies are normally closed entities from which alien individuals are excluded. The occasional fusion of unrelated colonies of the thelytokous ant Platythyrea punctata is therefore puzzling, because it strongly intensifies competition among nestmates for the replacement of an old reproductive. Most colonies of P. punctata have only one or...

Aim  We investigated the spatio-temporal patterns of genetic diversity in West Indian and mainland populations of a widespread parthenogenic ant (Platythyrea punctata F. Smith) to infer source populations and subsequent colonizations across its geographic range. Location  Central America, Texas and the West Indies (Florida, the Bahamas, Greater an...

Social insects harbor diverse assemblages of bacterial microbes, which may play a crucial role in the success or failure of biological invasions. The invasive fire ant Solenopsis invicta (Formicidae, Hymenoptera) is a model system for understanding the dynamics of invasive social insects and their biological control. However, little is known about...

The evolutionary stability of cooperation and altruism in colonies of social insects requires that nestmates be to some extent related. An efficient system of discrimination against non-nestmates protects the nest against unrelated conspecifics, which might exploit or parasitize the colony. The co-occurrence of unrelated individuals in mature colon...

Animals often exhibit particular 'personalities', i.e. their behaviour is correlated across different situations. Recent studies suggest that this limitation of behavioural plasticity may be adaptive, since continuous adjustment of one's behaviour may be time-consuming and costly. In social insects, particularly aggressive workers might efficiently...

Thelytokous parthenogenesis, the production of diploid female offspring from unfertilized eggs, can be caused by several cytological mechanisms, which have a different impact on the genetic variation on the offspring. The ponerine ant Platythyrea punctata is widely distributed throughout the Caribbean Islands and Central America and exhibits facult...

In the parthenogenetic ant Platythyrea punctata policing behaviour is not expected on relatedness grounds as workers are normally clonemates and thus equally related to all offspring in the colony. Nevertheless, colonies usually contain only a single reproductive and other workers that begin to lay eggs are attacked by their nestmates (‘policing’)....

Kin selection theory predicts not only cooperation, but also conflict within social insect societies. Under kin selection theory, individuals should favor close relatives other non relatives, a behavior known as nepotism. Such nepotistic behavior is expected to occur in policing, where workers prevent each other from laying eggs dependent on the re...

In the ponerine ant Platythyrea punctata colonies are queenless and the predominant mode of reproduction is thelytoky (females can emerge from unfertilized parthenogenetic laid eggs). Therefore female workers are totipotent and theoretically each young worker can become reproductive. However, reproduction is monopolized by a single female. Because...

Although all female Hymenoptera are capable of laying haploid eggs that develop parthenogenetically into males (arrhenotoky), very few are capable of laying unfertilised eggs that turn into diploid females (thelytoky). Once such species is the neotropical ponerine ant, Platythyrea punctata. This species appears to be primarily clonal on Caribbean i...

Social insects, ants in particular, show considerable variation in queen number and mating frequency resulting in a wide range of social structures. The dynamics of reproductive conflicts in insect societies are directly connected to the colony kin structure, thus, the study of relatedness patterns is essential in order to understand the evolutiona...

Hymenoptera (ants, bees and wasps) are characterized by a haplodiploid mechanism of sex determination, in which males emerge from unfertilised eggs and are haploid, whereas females develop from fertilised eggs and are diploid. In most taxa, workers do not mate but are capable of laying haploid eggs that develop into males (arrhenotokous parthenogen...

In the ant Pachycondyla villosa, new colonies are usually started cooperatively by two or more young queens who establish a dominance order with a division of labour. Co-founding can lead to primary polygyny, where queens stay together after workers have emerged. Here we show that two queens associations are the most common (47%) and also the most...

Cuticular lipids play an important role in recognition process of social insects both at the colony and at the individual level. Indeed, there is evidence for a correlation between cuticular profile and reproductive status in some wasps and ants. For example, in the ponerine ant Pachycondyla inversa queens and workers show a very similar cuticular...

Other than in many other ant species, young queens of the two closely related species Pachycondyla inversa and Pachycondyla villosa do not only found new colonies together (pleometrosis), but coexist also after the first workers have emerged (primary polygyny). During the founding phase, queens establish a linear dominance hierarchy by aggressive i...

Hymenopterans generally exhibit a haplo-diploid sex determination mechanism, in which females are produced by sexual reproduction and are diploid and males are produced parthenogenetically and are haploid. In a small number of ant species, workers are able to produce diploid female offspring parthenogenetically from unfertilized eggs, which is term...