Meetings in Microbial Ecology & Evolution: Evolutionary Dynamics & Processes

Session

Poster Session

31 May 2022, 16:30

45. Bacterial evolution during chronic inflammation and its potential for ancestral state restorative therapy

Rahul Unni (MPI Evolutionary Biology)

The basic evolutionary principle of adaptation by natural selection applies to the natural microbial populations in our microbiomes. Disease-mediated changes in the intestinal environment would impose different selection pressures on the microbiome to what we would expect in healthy individuals, resulting in selection for disease-specific microbial traits. Inflammatory bowel disease (IBD)...

34. Binding affinity landscapes constrain the evolution of broadly neutralizing anti-influenza antibodies

Angela Phillips (Harvard University )

Several broadly neutralizing antibodies (bnAbs) that confer protection against diverse influenza strains have been identified. Still, our understanding of the evolutionary pathways leading to these rare antibodies, and thus how best to elicit them, remains limited. To address this, we measure equilibrium dissociation constants of combinatorially complete mutational libraries (of up to ~100k...

37. Differences in tigecycline resistance between a clinical and a laboratory strain of Acinetobacter baumannii highlight the importance of evolutionary history in adaptation.

Alecia Rokes (University of Pittsburgh )

Antimicrobial resistance (AMR) is a rapidly worsening global health issue, with an increasing number of bacterial infections becoming impossible to treat with most drugs. Of serious concern is Acinetobacter baumannii, a nosocomial and highly multidrug resistant (MDR) pathogen. Although resistance is often attained through common mechanisms, such as increased drug efflux and modifications to...

46. Emergence and Maintenance of Stable Coexistence in Snowflake Yeast Long Term Evolution Experiment

Rozenn Pineau (Georgia Institute of Technology )

The evolution of multicellularity created new ecosystems, fundamentally changing Earth’s ecology (Szathmáry & Smith, 1995). While multicellularity has evolved numerous times in diverse lineages (Knoll et al. 2011), no prior work has directly examined the impact of this major evolutionary transition on multicellular diversity. Using long-term experimental evolution, we show that the evolution...

42. EvoDM achieves superior population control in an in siclico system of evolution.

Davis Weaver (Case Western Reserve University )

Drug resistant pathogens are a wide-spread and deadly phenomenon that infect nearly 3 million individuals in the United States each year. If microbial resistance continues to develop at the current rate, bacterial infections are expected to surpass cancer as the leading cause of death worldwide by 2050. Novel approaches to designing therapy that explicitly take into account the adaptive nature...

44. Evolution of bacterial populations in response to antibiotic and spatial structure

Mahfuza Akter (Clarkson University)

When exposed to antibiotics, a population of bacteria may evolve resistance through the combination of random mutation and natural selection driving fixation of antibiotic resistance mutations. However, in a natural environment, a complex suite of stressors simultaneously drive natural selection and depending on their trade-offs and/ or interactions may impact adaptive evolution. Spatial...

48. Evolving evolvability via lineage selection

Michael Barnett (MPI for Evolutionary Biology)

Evolution can be viewed as a game where the object is to keep playing. From this perspective, focus is brought to the properties of lineages that enable their success over long spans of evolutionary time, rather than the phenotypes and performance of individuals in the contemporary environment. One property required for long-term evolutionary success is the ability of a lineage to translate...

33. Hedging bets by aneuploidy

Duncan Greig (UCL)

How can organisms cope with environmental change? Some evolutionary strategies, such as adaptive tracking (adapting directly to a changed environment via mutations) or phenotypic plasticity (sensing and responding to previously-experienced changes via physiology or development) can be readily tested experimentally. But adaptive bet-hedging, the strategy of producing random variation to insure...

49. Lineage-specific genes: evolutionary novelties or technical artifacts? How to tell and why it matters

Cara Weisman (Princeton University)

“Lineage-specific” genes appear to have homologs only in a restricted group of related species, strikingly absent from the rest of the tree of life. They are often interpreted as novel genes, receiving much interest related to their apparent potential to underlie evolutionary innovation. An alternative, “null” hypothesis is that these genes are not meaningfully novel: they do have existing...

43. Microbial evolutionary dynamics in industrial bioethanol fermentors

Artur Rego-Costa (Harvard University )

The past decades of experimental evolution in controlled laboratory conditions have established that microbial evolutionary dynamics are largely complicated by clonal interference and hitchhiking, making the process of adaptation hard to model and predict. Harnessing evolutionary knowledge for applied purposes is further complicated by how the various relevant microbial populations in health...

35. Multicellular dynamics and evolution in dense populations

Jona Kayser (Max Planck Zentrum für Physik und Medizin, Erlangen, Germany )

Many cellular populations are tightly packed, including microbial colonies and biofilms, or tissues and tumours in multicellular organisms. However, little is known about how ensuing mechanical cell-cell interactions reshape evolutionary dynamics and critical outcomes, such as drug resistance. Here, I will show how growth-induced collective motion inherently suppresses the differential...

50. Poster Kyle Card

Kyle Card (Cleveland Clinic)

The evolution of antibiotic resistance is a serious and growing problem. The ability to predict a pathogen’s capacity to evolve resistance is therefore a critical public-health goal. In previous work, we found that differences between genetic backgrounds can sometimes lead to unpredictable responses in phenotypic resistance and influence its genetic basis by channeling evolution down...

32. Predictors of viability and genomic instability in yeast hybrids

Rike Stelkens (Stockholm University )

The genomes of hybrids often show substantial deviations from the features of the parent genomes, including genomic instabilities characterized by chromosomal rearrangements, gains, and losses. This plastic genomic architecture generates phenotypic diversity, giving hybrids access to new ecological niches. We asked if there are any generalizable patterns and predictability in the type and...

40. Protein evolution in a host-pathogen battle for iron

Tera Levin (University of Pittsburgh)

Hosts and pathogens frequently engage in physiological and evolutionary 'battles for iron', as each adapts to sequester this essential nutrient. We focus on the battle for iron between the intracellular bacterium Legionella pneumophila and its natural hosts, free-living amoebae. Amoebae restrict Legionella replication by pumping iron out of the Legionella-containing vacuole. In turn, the...

36. Short-term evolution of antibiotic responses in fast-changing environments favors loss of regulation

Daniel Schultz (Dartmouth College Geisel School of Medicine )

Microbes inhabit natural environments that are remarkably dynamic, with sudden environmental shifts that require immediate action by the cell. The genetic control of cellular responses therefore evolve according to the specific demands of their environment, resulting in different strategies such as transcriptional regulation or stochastic switching. However, when microbes are exposed to...

47. The effect of cis-acting elements on copy number variant formation and dynamics during adaptive evolution

Julie Chuong (New York University)

Detecting and predicting heritable changes in DNA that lead to adaptation is an essential goal in evolutionary biology. Copy number variants (CNVs) -- gains and losses of genomic sequences -- are a pervasive class of mutation and source of genetic variation that frequently underlie rapid adaptation. Although mechanisms of CNV formation have been identified, the role of local genomic...

39. The roles of history, chance, and natural selection in the evolution of antibiotic resistance

Alfonso Santos-Lopez (Hospital Universitario Ramón y Cajal )

History, chance, and selection are the fundamental factors that drive and constrain evolution. We designed evolution experiments to disentangle and quantify effects of these forces on the evolution of antibiotic resistance. Previously, we showed that selection of the pathogen Acinetobacter baumannii in both structured and unstructured environments containing the antibiotic ciprofloxacin...

31. Transposable elements promote the evolution of genome streamlining

Bram van Dijk (MPI for Evolutionary Biology)

Eukaryotes and prokaryotes have distinct genome architectures, with marked differences in genome size, the ratio coding/non-coding DNA, and the abundance of transposable elements (TEs). As TEs replicate independently of their hosts, the proliferation of TEs is thought to have driven genome expansion in eukaryotes. However, prokaryotes also have TEs in intergenic spaces, so why do prokaryotes...

38. Underestimated infectious potential of plasmids that repress their own transfer

Jeff Smith (University of Missouri-St Louis)

Plasmids are mobile genetic elements that horizontally transfer antibiotic resistance and virulence factor genes among bacteria. It's unclear if plasmids persist only through selection for the genes they carry or if they are infectious enough to persist as genomic parasites. Here we show that plasmids' infectious potential is severely underestimated by theoretical models and experimental...

41. Understanding the evolutionary implications of gene duplications and mechanisms of their maintenance in long-term evolutionary timescales

Subrata Mishra (Affiliation )

Gene duplications have been proven to introduce variation by providing basic genetic material mainly those with adaptive functions. The pervasive choice of evolutionary pathway in the form of duplications in all three domains of life , including mammals, plants, yeast, bacteria, and archaea has been observed by analysis of their respective genomes. The significance of gene duplication can be...