2011 — 2016 |
Wilson, Alexandra Price, Daniel |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Characterization of Aphid Nutrient Amino Acid Transporters With Focus On the Symbiotic Interface
Alexandra C. C. Wilson Proposal # IOS-1121847 Characterization of Aphid Nutrient Amino Acid Transporters with Focus on the Symbiotic Interface Symbioses such as those between humans and their gut flora and the insect vector of Chagas disease and its obligate bacterium are ubiquitous in nature impacting human health, biodiversity and agriculture. Insects feeding on mammalian blood or plant sap are united in their dependence on intimate symbioses with bacteria that nutritionally compensate their hosts. While the nutritional bases of these symbioses are well understood, the processes and structures that mediate the intimate interactions between symbiotic partners have been neglected and remain uncharacterized. This project aims to functionally characterize the processes and structures that mediate amino acid exchange between aphids and their bacterial symbiont, Buchnera aphidicola. Buchnera live within membrane-bound compartments inside aphid bacteriocyte cells. The membranes of the bacteriocytes and the specialized compartments present a challenge to amino acid exchange, a process vital to aphid survival. Specifically, this project focuses on studying the molecules that transport amino acids across membranes at the aphid/Buchnera interface. The investigators will experimentally determine the transport capability of amino acid transporters and use microscopy to determine where these transporters are found. Research and educational goals will merge in measurement of changes in expression of amino acid transporter genes in response to dietary amino acid supply providing inquiry-based research training for up to 96 undergraduates. Broadly this work benefits genomic studies in all insect systems and additionally provides mentoring and research training for one graduate student and one early-career researcher. This project will be the first to functionally characterize the processes and structures operating at the interface of an insect nutritional symbiosis. Importantly, understanding how insects interact with their symbionts has the potential to facilitate development of targeted environmentally safe control of insect vectors of human and plant disease.
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2014 — 2016 |
Duncan, Rebecca Wilson, Alexandra |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Dissertation Research: Mechanisms Driving Evolutionary Innovation Through Gene Duplication in the Amino Acid Transporters of Sap-Feeding Insects
Gene duplication is important for evolutionary innovation. When genes duplicate, the copies are identical at first but can evolve in different directions resulting in the evolution of new genes, new metabolic pathways and even new developmental pathways. We know genes duplicate often but we don?t fully understand the processes and mechanisms that drive independent evolution of duplicate genes. Co-PI Duncan and PI Wilson will test among different hypotheses of how duplicated genes evolve by examining the evolutionary trajectory of several gene copies following duplication. Their research will focus on the citrus mealybug, a sap-feeding insect that underwent extensive duplication in genes that transport amino acids, nutrients that are essential for normal cellular function in all organisms. The PIs will compare expression and amino acids transported between three types of amino acid transporters: (1) duplicated mealybug transporters, (2) related single-copy transporters in other insects, and (3) the extinct mealybug transporter that Duncan and Wilson will synthetically resurrect. Further, Duncan and Wilson will use computer programs to test the role of natural selection during the evolution of duplicated amino acid transporters in the mealybug.
This project will establish which evolutionary and molecular mechanisms are most important in the evolution of duplicated amino acid transporters in the citrus mealybug. The results will contribute to our general understanding of the importance of different mechanisms in the evolution of gene copies following gene duplication, and thus the role these mechanisms play in driving evolutionary innovation across the tree of life. Further, amino acid transporters are essential for survival, so this research could identify potential targets for controlling populations of the citrus mealybug, a pest of citrus and other commercially important plants. By providing opportunities for University of Miami undergraduates to conduct research in a lab setting under the mentorship of co-PI Duncan, this project will advance discovery and learning. Undergraduates at the University of Miami are culturally and ethnically diverse, providing research opportunities for undergraduates underrepresented in the biological sciences. Finally, Duncan and Wilson will share their findings with the general public in a Department of Biology open house that co-PI Duncan will organize during the University of Miami Alumni Week.
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2014 — 2018 |
Wilson, Alexandra Luetje, Charles (co-PI) [⬀] |
N/AActivity Code Description: No activity code was retrieved: click on the grant title for more information |
Ios: Nutrient Exchange and Regulation At the Aphid Symbiotic Interface
Symbioses between eukaryotic hosts and bacterial consortia are fundamentally important to human health and ecosystem function. Gathering large amounts of DNA sequence data has become relatively easy and thus, models of host/microbiome function are accumulating. Critically, most models lack experimental tests. Working in a system that involves one eukaryotic host paired with a single bacterial symbiont the investigators will test models of symbiotic function to identify fundamental design principles in symbiosis.
The project will exploit a very productive collaboration to further examine the nature of nutrient transport and regulation in insects; specifically, the investigators will exploit the model aphid, Acyrthosiphon pisum, and its symbiont, Buchnera aphidicola, to fully characterize the substrate and feedback regulation of transporters between the aphid and bacterium. The first objective targets testing whole genome based models of symbiotic function and regulation. The research team will transiently express transporters of sap-feeding insects in oocytes of the South African clawed frog to test genome sequence based models of symbiotic function and host/symbiont regulation. Because aphids are both a significant crop pest and excellent models for the study of symbiosis any work that increases understanding of basic aphid biology increases our ability to develop ecologically safe methods of pest control and may facilitate development of the aphid as a model for understanding the process of bacterial infection. Functional characterization of transporters in the pea aphid and related insects will facilitate comparative work in other insect systems thus benefitting the annotation of transporters in all arthropod genomes. The second objective targets bringing NSF-funded basic research into the lives of Americans through the production of six broadcast quality films about aphids, the science of symbiosis and life as a scientist. The films will be supported by development of curricular resources that target early childhood and middle school children. Finally, this project supports the research program of a mid-career female scientist.
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