A5087484628- Evolution and Genetic Dynamics
- Algal biology and biofuel production
- Fungal and yeast genetics research
- Evolutionary Game Theory and Cooperation
- Microbial Community Ecology and Physiology
- Microbial Metabolic Engineering and Bioproduction
- Fermentation and Sensory Analysis
- Marine and coastal plant biology
- Biofuel production and bioconversion
- Protist diversity and phylogeny
- Bacterial Genetics and Biotechnology
- Genomics and Phylogenetic Studies
- Aquatic Ecosystems and Phytoplankton Dynamics
- Yeasts and Rust Fungi Studies
- CRISPR and Genetic Engineering
- Genetics, Bioinformatics, and Biomedical Research
- Marine and coastal ecosystems
- Gene expression and cancer classification
- Gene Regulatory Network Analysis
- Bacterial biofilms and quorum sensing
- Planetary Science and Exploration
- Plant and animal studies
- Bioinformatics and Genomic Networks
- Chromosomal and Genetic Variations
- Genetics, Aging, and Longevity in Model Organisms
Georgia Institute of Technology
2016-2025
University of Montana
2013-2024
Parker Hannifin (United States)
2024
Synthetic Biologics (United States)
2020
University of Michigan
2002
Stanford University
2002
Howard Hughes Medical Institute
2002
University of Florida
2002
Florida College
2002
Genome rearrangements, especially amplifications and deletions, have regularly been observed as responses to sustained application of the same strong selective pressure in microbial populations growing continuous culture. We studied eight strains budding yeast ( Saccharomyces cerevisiae ) isolated after 100–500 generations growth glucose-limited chemostats. Changes DNA copy number were assessed at single-gene resolution by using microarray-based comparative genomic hybridization. Six these...
ABSTRACT Engaging large numbers of undergraduates in authentic scientific discovery is desirable but difficult to achieve. We have developed a general model which faculty and teaching assistants from diverse academic institutions are trained teach research course for first-year undergraduate students focused on bacteriophage genomics. The situated within broader context aimed at understanding viral diversity, such that collaborators with established researchers the field. Howard Hughes...
The transition from unicellular to multicellular life was one of a few major events in the history that created new opportunities for more complex biological systems evolve. Predation is hypothesized as selective pressure may have driven evolution multicellularity. Here we show de novo origins simple multicellularity can evolve response predation. We subjected outcrossed populations green alga Chlamydomonas reinhardtii selection by filter-feeding predator Paramecium tetraurelia. Two five...
The transition to multicellularity enabled the evolution of large, complex organisms, but early steps in this remain poorly understood. Here we show that multicellular complexity, including development from a single cell, can evolve rapidly unicellular organism has never had ancestor. We subject alga Chlamydomonas reinhardtii conditions favour multicellularity, resulting life cycle which clusters reproduce via motile propagules. While single-cell genetic bottleneck during ontogeny is widely...
As organisms adaptively evolve to a new environment, selection results in the improvement of certain traits, bringing about an increase fitness. Trade-offs may result from this process if function other traits is reduced alternative environments either by adaptive mutations themselves or accumulation neutral elsewhere genome. Though cost adaptation has long been fundamental premise evolutionary biology, existence and molecular basis for trade-offs are not well-established. Here, we show that...
Genome rearrangements are associated with eukaryotic evolutionary processes ranging from tumorigenesis to speciation. Rearrangements especially common following interspecific hybridization, and some of these could be expected have strong selective value. To test this expectation we created de novo yeast hybrids between two diverged but largely syntenic Saccharomyces species, S. cerevisiae uvarum, then experimentally evolved them under continuous ammonium limitation. We discovered that a...
Microbial populations founded by a single clone and propagated under resource limitation can become polymorphic. We sought to elucidate genetic mechanisms whereby polymorphism evolved in Escherichia coli glucose persisted because of cross-feeding among multiple adaptive clones. Apart from 29 kb deletion the dominant clone, no large-scale genomic changes distinguished clones their common ancestor. Using transcriptional profiling on co-evolved cultured separately glucose-limitation we...
Abstract Background Interspecific hybridization occurs in every eukaryotic kingdom. While hybrid progeny are frequently at a selective disadvantage, some instances their increased genome size and complexity may result greater stress resistance than ancestors, which can be adaptively advantageous the edges of ancestors' ranges. this phenomenon has been repeatedly documented field, response populations to long-term selection not often explored lab. To fill knowledge gap we crossed two most...
Significance All cells age and do so in relation to how many times a cell divides (replicative aging) long nondividing can live (chronological aging). Bakers’ yeast has been used study both, but because when nutrient levels permit, the genetics of its chronological lifespan only studied under calorie restriction, mimicked by starvation. Because terminally differentiated animal are long-lived rarely starve, we developed model calorie-unrestricted conditions. When encapsulated fed ad libitum,...
A major goal of genetics is to define the relationship between phenotype and genotype, while a ecology identify rules that govern community assembly. Achieving these goals by analyzing natural systems can be difficult, as selective pressures create dynamic fitness landscapes vary in both space time. Laboratory experimental evolution offers benefit controlling variables shape landscapes, helping achieve goals. We previously showed clonal population E. coli experimentally evolved under...
Cross-feeding, a relationship wherein one organism consumes metabolites excreted by another, is ubiquitous feature of natural and clinically-relevant microbial communities could be key factor promoting diversity in extreme and/or nutrient-poor environments. However, it remains unclear how readily cross-feeding interactions form, therefore our ability to predict their emergence limited. In this paper we developed mathematical model parameterized using data from the biochemistry ecology an E....
Abstract Background Throughout its nearly four-billion-year history, life has undergone evolutionary transitions in which simpler subunits have become integrated to form a more complex whole. Many of these opened the door innovations that resulted increased biodiversity and/or organismal efficiency. The evolution multicellularity from unicellular forms represents one such transition, paved way for cellular differentiation, including differentiation male and female gametes. A useful model...
Abstract Background The volvocine algae, which include the single-celled species Chlamydomonas reinhardtii and colonial Volvox carteri , serve as a model in to study evolution of multicellularity cellular differentiation. Studies reconstructing history this group have by large relied on datasets one few genes for phylogenetic inference ancestral character state reconstruction. As result, phylogenies lack concordance depending number and/or type (i.e., chloroplast vs nuclear) chosen...
The evolution from unicellular to multicellular organisms facilitates further phenotypic innovations, notably cellular differentiation. Multiple research groups have shown that in the laboratory simple, obligate multicellularity can evolve a ancestor under appropriate selection. However, little is known about extent which deterministic factors such as ancestral genotype and environmental context influence likelihood of this evolutionary transition. To test whether certain genotypes are...
ABSTRACT Evolutionary adaptation of Pseudomonas aeruginosa to the cystic fibrosis lung is limited by genetic variation, which depends on rates horizontal gene transfer and mutation supply. Because each may increase following secondary infection or mutator emergence, we sought ascertain incidence variability in populations containing lacking mutators. Forty-nine strains collected over 3 years from 16 patients were phenotyped for antibiotic resistance status genotyped repetitive-sequence PCR...
The presence of perchlorate on Mars suggests a possible energy source for sustaining microbial life. Perchlorate-reducing microbes have been isolated from perchlorate-contaminated soils and sediments the Earth, but to date, never an environment that is naturally enriched in perchlorate. arid Pilot Valley paleolake basin Utah analog whose are with up ∼6.5 μg kg−1 oxyanions. Here, we present results field laboratory studies indicating perchlorate-reducing microorganisms co-occur this potential...
The productivity of a biological community often correlates with its diversity. In the microbial world this phenomenon can sometimes be explained by positive, density-dependent interactions such as cross-feeding and syntrophy. These metabolic help account for astonishing variety life drive many biogeochemical cycles without which we know it could not exist. While is difficult to recapitulate experimentally how these evolved among multiple taxa, explore in laboratory they arise within one....
:Volvox capensis was recorded previously only from South Africa. Here we established culture strains of this species a sample collected in Montana, USA. Morphological details asexual and sexual spheroids molecular phylogeny these were studied. The present alga identified as V. on the basis morphological characteristics zygotes. However, differences between Montana African materials recognized number sperm packets sexual, monoecious spheroid well mode gametic union eggs. Possible polyspermy...
The advent of multicellularity was a watershed event in the history life, yet transition from unicellularity to is not well understood. Multicellularity opens up opportunities for innovations intercellular communication, cooperation, and specialization, which can provide selective advantages under certain ecological conditions. unicellular alga Chlamydomonas reinhardtii has never had multicellular ancestor it closely related volvocine algae, clade containing taxa that range simple unicells...
ABSTRACT Homology searches indicate that Saccharomyces cerevisiae strain BY4741 contains seven redundant genes encode putative aryl-alcohol dehydrogenases (AAD). Yeast AAD are located in subtelomeric regions of different chromosomes, and their functional role(s) remain enigmatic. Here, we show two these genes, AAD4 AAD14 , enzymes reduce aliphatic aryl-aldehydes concomitant with the oxidation cofactor NADPH, Aad4p Aad14p exhibit substrate preference patterns. Other yeast undergoing...