Arizona State University (1 PhD; Cease, Overson)
Baylor College of Medicine (4 PhD; Dierick, Gabbiani, Zong)
Texas A&M University (4 PhD; Behmer, Song, Sword)
University of Washington at St. Louis (2 PhD; Raman)
Southern Illinois University Edwardsville (1 MS; Peterson)
Research Topic Overview. Phenotypic plasticity—the ability of a genotype to produce different phenotypes in response to environmental variation—is observed across all living organisms and scales of biological organization. However, to fully understand its mechanisms, maintenance, and evolution, complete biological integration is needed. One of the most striking examples of coordinated phenotypic plasticity in nature is found in locusts. Locusts comprise a handful of species in the grasshopper family Acrididae capable of forming dense migrating swarms through an extreme form of density dependent phenotypic plasticity. Cryptically colored, shy individuals (solitarious phase) can transform into conspicuously colored, gregarious individuals (gregarious phase) in response to increases in population density. This phenomenon, referred to as locust phase polyphenism, affects a myriad of locust traits, including molecular biology, physiology, behavior, morphology, and ecology. Locust swarms occur worldwide and can affect the livelihood and well-being of one in ten people on Earth. Thus, locust phase polyphenism is a powerful comparative system for understanding how gene expression and epigenetic regulation scale up to behavioral, physiological, and ecological interactions resulting in outbreaks, collective movement, and mass migration, with major food security implications. Intriguingly, the syndrome of locust phase polyphenism has evolved multiple times within grasshoppers, with varying sets of mechanisms contributing to phase polyphenism between lineages. The BPRI will characterize, compare, and integrate this phenomenon in a phylogenetic framework.
Students will be primarily based in the laboratory of their main PI, but will collaborate with other BPRI research groups.
The vision of the BPRI is predicated on integration through collaboration. We recognize the scientific and societal impacts are maximized when groups of people with diverse backgrounds and experiences come together to work towards shared goals and the common good. This philosophy will inform all BPRI activities.
Research Activities – Associated Faculty
The overall research goal of the BPRI is to integrate (i) suborganismal processes of locust phase polyphenism, which will be investigated from genomic, epigenomic, transcriptomic, and neurophysiological perspectives using powerful genome-editing tools, with (ii) organismal biology and ecology, which will be investigated using manipulative lab-based and field-based experiments, (iii) in a phylogenetic framework. The BPRI aims to investigate three locust species and three grasshopper species in the genus Schistocerca (Orthoptera: Acrididae) that vary in their degrees of density-dependent phenotypic plasticity. The desert locust, S. gregaria, has been extensively researched during the last 25+ years and its newly sequenced genome, as well as our preliminary quantification of density-dependent phenotypic plasticity of the other five species (based on behavior and transcriptome data) serve as a basis for formulating our research projects.
We have 10 integrative research activities (R1-10) to achieve our goal. In all cases we will generate data for all six Schistocerca species.
(R1) Whole genome sequencing and assembly
Associated Faculty (Lieberman Aiden, Childers, Dudchenko, and Richards)
(R2) Tissue-specific transcriptomes during phase change
Associated Faculty (Song)
(R3) Time-resolved and tissue-specific epigenomic profiling during phase change
Associated Faculty (Zong)
Research activities R1, R2, and R3 will provide foundational knowledge on the molecular basis of density-dependent phenotypic plasticity. This information will be used to identify key ‘plasticity’ genes and epigenetic regulation mechanisms.
We will study phenotypic plasticity using a functional genetics approach.
(R4) Development of genome editing tools to probe phase change
Associated Faculty (Dierick)
Research activity R4 will fundamentally transform the study of phenotypic plasticity. We will also investigate the proximate mechanisms of density-dependent phenotypic plasticity.
(R5) Single-cell characterization of state-specific visual processing in collision avoidance
Associated Faculty (Gabbiani)
(R6) Neuronal basis of density-dependent changes in behavior and processing
Associated Faculty (Raman)
Based on the integrative findings of R5 and R6, we will characterize how ‘plasticity’ genes affect individual gregarious behaviors and collective movement in response to changes in density by using established reverse genetics tools.
(R7) Genetic basis of individual behavioral plasticity and group-level collective movement
Associated Faculty (Sword)
We will integrate organismal physiology and ecology into the study of phenotypic plasticity by comparing behavioral phenotypes (aggregation, foraging, and migration) across lab and field populations. This will allow us to test for ecological factors that might constrain or promote the development of gregarious phenotypes using satellite data.
(R8) Density-dependent nutritional physiology and metabolism including molecular insights
Associated Faculty (Behmer)
(R9) Integrating lab to field research (locust migration, nutrition, and gut microbiomes)
Associated Faculty (Cease, Overson, Peterson)
Finally, we will compare and contrast the genomes and all measured reaction norms using a phylogenetic framework. This will give us a comprehensive view of how phenotypic plasticity has evolved. This approach also allows us to integrate how density affects phenotypes at different levels of biological organization, from the genome to the organism to populations, and how density-dependent phenotypic plasticity has evolved across phylogeny.
(R10) Phylogenetic comparison of density-dependent phenotypic plasticity
Associated Faculty (Song)
The collective insights gained from integration across our 10 research activities will be holistic and transformative. Graduate students in the BPRI will be part of a unique learning environment where they will learn and grow to become a new generation of scientists that conduct integrative behavioral research. The experience of being part of the BPRI will be more than the sum of its parts. We encourage all students interested in this trans-level (from molecular/cell biology, to neuroscience, behavior, physiology and ecology) multi-university training and research approach to apply!
Applicants should be able to work independently, as well as part of a team, and be highly motivated. Some previous research and/or field experience is necessary.
Bachelor’s Degree in related fields e.g. ecology, biology, entomology, genetics, microbiology, sustainability is required.
Applicants should contact PI’s via email before applying to discuss the project and fit.
Dr. Spencer Behmer (Professor, Texas A&M University)
Dr. Arianne Cease (Associate Professor, Arizona State University)
Dr. Anna Childers (Computational Biologist, USDA ARS)
Dr. Herman Dierick (Associate Professor, Baylor College of Medicine)
Dr. Fabrizio Gabbiani (Professor, Baylor College of Medicine)
Dr. Erez Lieberman (Assistant Professor, Baylor College of Medicine)
Dr. Rick Overson (Senior Sustainability Scientist, Arizona State University)
Dr. Brittany Peterson (Assistant Professor, Southern Illinois University Edwardsville)
Dr. Barani Raman (Professor, Washington University in St. Louis)
Dr. Stephen Richards (Project Scientist, University of California Davis)
Dr. Hojun Song (Associate Professor, Texas A&M University)
Dr. Greg Sword (Professor, Texas A&M University)
Dr. Olga Dudchenko (Research Assistant Professor, Baylor College of Medicine)
Dr. Chuck Zong (Assistant Professor, Baylor College of Medicine)