About

Ann Fallon is a Distinguished McKnight University Professor in the Department of Entomology at the University of Minnesota. Her research focuses on the reproductive physiology of insects, with particular emphasis on the molecular and biochemical mechanisms underlying insect reproduction and host-microbe interactions. Her early work involved studying hormonal control of egg production in the mosquito Aedes aegypti, where she used radioimmunoassays to quantify yolk protein synthesis and discovered that the insect steroid hormone 20-hydroxyecdysone is secreted by the ovary after a blood meal, activating vitellogenin gene expression in the fat body. During her PhD at Queen's University, she investigated cyclic nucleotide metabolism in the house cricket Acheta domesticus, exploring the roles of cGMP and cAMP in insect processes. Her postdoctoral work included molecular studies on ribosomal proteins in E. coli, lepidopteran cell culture, baculoviruses, and arboviruses in mosquito cell lines, focusing on molecular aspects of mosquito reproduction, gene amplification, cell cycle synchronization, and gene transfer. Her recent research centers on Wolbachia, an obligate intracellular bacterium affecting insect reproduction, particularly its role in cytoplasmic incompatibility in mosquitoes. She aims to develop cell culture protocols to manipulate Wolbachia in vitro and explore its metabolic interactions with host cells, with the goal of engineering Wolbachia for pest control applications.

Research topics

• Genetics
• Biology
• Ecology
• Virology

Selected publications

• The Further Surprising Adventures of the Scholarship of <i>Robinson Crusoe</i>

  Eighteenth-Century Life · 2025-01-01

  article1st authorCorresponding

  Anthologies, journal articles, and edited collections about Robinson Crusoe continue to emerge from the presses every year, almost as ubiquitous as the famous Robinsonades that became their own genre in the eighteenth century. The proliferation of scholarship around Robinson Crusoe, like the proliferation of Robinsonades, represents not just the influence of Crusoe as a text, but also the influence of the idea of Crusoe, the myth, to use Ian Watt's description, separate from the existence of the novel.1 As one of the most recent additions to this body of scholarship, Robinson Crusoe after 300 Years traces the influence of both text and myth in the past three centuries. In doing so, it contributes to the continuing legacy of the novel, but also strikingly overlooks the significance of race in that legacy.The ten essays in this new collection are widely varied. They move between discussions of Robinsonades at 300, including the newest iterations of Crusoe in the early part of the twenty-first century, to discussions of images of Crusoe over the past three hundred years. The collection is divided into three sections: “Generic Revisions,” “Mind and Matter,” and “Character and Form.” In “Generic Revisions,” three essays take up different reimaginings of Crusoe: the first essay looks at the novel and the film The Martian; the next focuses on the gendered characterizations of Crusoe in pantomimes that ran in the late eighteenth century in the UK, and in the late nineteenth century in the United States; and finally, the last essay in this section examines close readings of six distinct “animal Crusoe” tales that, according to coauthors Amy Hicks and Scott Pyrz, define an important and yet overlooked type of Robinsonade. What pulls these three essays together is the authors’ insistence on seeing these Robinsonades as complete works unto themselves, not just as reinventions of the first novel. These stories also serve as commentaries on the ghostly image of Crusoe that haunts different eras and genres.The second section, “Mind and Matter,” begins with an essay by Laura Brown in which she closely examines the inanimate objects in Crusoe's tale, especially his infamous pot. Brown, looking at Defoe's representation of things, of matter, in the context of Newtonian theory, persuasively argues that modern ideas on the influence of physical forces can be traced to the debate around “matter” in the early eighteenth century. Of the four essays in this section, I found Brown's to be the most compelling; the three other essays look at tobacco, the ocean, and the concept of boredom.Finally, in the last section of this collection, “Character and Form,” the authors place Crusoe in an international context. In the very brief first essay in this section, Benjamin Pauley considers Crusoe as a rambler, and uses The Farther Adventures of Robinson Crusoe to demonstrate Crusoe's unchanging rambling ways. He never settles in England, as we might assume if we just stop at the more famous volume 1, but remains “a mad rambling boy” through the end of the second volume of Crusoe's adventures (162). This tight study of Crusoe's rambling sets the stage for the essay by the renowned Defoe scholar Maximillian Novak. Novak examines Crusoe's encounters with “others” from around the globe in his “farther” global ramblings and reads Crusoe as a man who is often deeply sympathetic to other points of views and who tries to understand and translate them to his readers at home. In the final essay of the collection, Andreas Mueller considers the name “Robinson Crusoe” as an icon that travels disconnected from the novel through the twenty-first century.One of the amazing qualities of Defoe's Robinson Crusoe, and perhaps the thing that really supports Watt's claim that the titular character truly has become the myth of the modern individual, is how the novel has come to seem contemporary and relevant to each new generation of readers. First, as the tale of a solitary castaway read by readers in the bustling and growing capital of London, it appealed to crowded Londoners longing for solitude. Today, as Mueller's essay argues, the name “Robinson Crusoe” is so abstracted from the original text that it lives on in the twenty-first century without referent, plastered on advertisements for resorts or bars. Relatedly, the idea of the lone castaway lives on in stories even if readers no longer recognize or are familiar with the original hero. Few general readers today are tackling the original novel or its nineteenth-century century abridgements. Instead, encounters with our hero happen unconsciously, embedded in our shared cosmopolitan culture, but often without us recognizing or acknowledging them. As just one example of this disconnect, Glynis Ridley notes in the opening essay that Andy Weir, the author of the novel, Bring Him Home: The Martian, denies any influence by our ur-castaway, claiming instead that, “I was more inspired by Apollo 13” (12).One of the striking things about Defoe himself, especially, is the breadth of his writings. He wrote under multiple pseudonyms and for multiple causes as well as publishers. As an entrepreneur, he covered a huge range of subjects, which is one of the things that stands out about this powerful volume; it scans a range of topics loosely connected to the problem of Robinson Crusoe. This edited volume on the 300th anniversary of the publication of Robinson Crusoe almost feels haphazard, as it moves from theme to theme, trying to capture new readings and explain revisions over the last three hundred years. In moving through various topics, from animal Crusoes to tobacco, from gender in burlesque, to connections between Newton's theory of matter and Defoe's novel, the editors run the risk of randomness, but instead manage to pack in a fascinating range of readings that focus on a text, and then move back out to attempt to capture a broader landscape.Absent in any of these essays, however, is an extended discussion of race; to read Crusoe and Friday after 300 years and not take into account race feels like a profound oversight and a missed opportunity. To read Crusoe in our own age and not recognize the shipwrecked boat as a slave ship and not see what Teju Olaniyan calls “the unforgettable image of submission in Friday's placing Crusoe's foot on his head” is itself a tragedy.2 Much of the Crusoe literature of the twentieth century grappled with this violence, from J. M. Coetzee, in both his Nobel Prize address and in his novel, Foe, to Derek Walcott's Caribbean plays and poems. As the United States and Great Britain both once again attempt to confront blackness today and especially with the “Black Lives Matter” movement in literature and our societies in 2024, this absence becomes especially troubling, like the mysterious footprint in the novel, which tells us something is there, but whatever it is, it remains invisible. I found myself coming to the end of the volume and wondering how we had come so far in our understanding of the place of Robinson Crusoe in British colonial history and yet had failed to come to terms with this legacy in our own critical moment

  PublisherDOI

• Resistance of Wolbachia to Trimethoprim: Insights into Genes Encoding Dihydrofolate Reductase, Thymidylate Synthase and Serine Hydroxymethyltransferase in the Rickettsiales

  Insects · 2024-12-28

  articleOpen access1st authorCorresponding

  Bacterial and eukaryotic dihydrofolate reductase (DHFR) enzymes are essential for DNA synthesis and are differentially sensitive to the competitive inhibitors trimethoprim and methotrexate. Unexpectedly, trimethoprim did not reduce Wolbachia abundance, and the wStri DHFR homolog contained amino acid substitutions associated with trimethoprim resistance in E. coli. A phylogenetic tree showed good association of DHFR protein sequences with supergroup A and B assignments. In contrast, DHFR is not encoded by wFol (supergroup E) and wBm (supergroup D) or by genomes of the closely related genera Anaplasma, Ehrlichia, Neorickettsia, and possibly Orientia. In E. coli and humans, DHFR participates in a coupled reactions with the conventional thymidylate synthase (TS) encoded by thyA to produce the dTMP required for DNA synthesis. In contrast, Wolbachia and other Rickettsiales express the unconventional FAD-TS enzyme encoded by thyX, even when folA is present. The exclusive use of FAD-TS suggests that Wolbachia DHFR provides a supplementary rather than an essential function for de novo synthesis of dTMP, possibly reflecting the relative availability of, and competing demands for, FAD and NAD coenzymes in the diverse intracellular environments of its hosts. Whether encoded by thyA or thyX, TS produces dTMP by transferring a methyl group from methylene tetrahydrofolate to dUMP. In the Rickettsiales, serine hydroxymethyltransferase (SMHT), encoded by a conserved glyA gene, regenerates methylene tetrahydrofolate. Unlike thyA, thyX lacks a human counterpart and thus provides a potential target for the treatment of infections caused by pathogenic members of the Rickettsiales.

  PublisherOA PDFDOI

• A rapid and simple micro-assay to assess catalase activity in individual mosquito tissues

  Experimental Parasitology · 2024-11-13 · 2 citations

  articleSenior authorCorresponding
  PublisherDOI

• Preparation of Infectious Wolbachia from a Mosquito Cell Line

  Methods in molecular biology · 2023-11-25 · 1 citations

  article1st authorCorresponding
  PublisherDOI

• Wolbachia: Advancing into a Second Century

  Methods in molecular biology · 2023-11-25

  article1st authorCorresponding
  PublisherDOI

• Paraquat is toxic to the soil-dwelling arthropod, Folsomia candida (Collembola: Isotomidae), and has potential effects on its Wolbachia endosymbiont

  Journal of Invertebrate Pathology · 2023-05-15 · 4 citations

  articleSenior authorCorresponding
  PublisherDOI

• Virus-like Particles from Wolbachia-Infected Cells May Include a Gene Transfer Agent

  Insects · 2023-06-02 · 6 citations

  articleOpen access1st authorCorresponding

  Wolbachia are obligate intracellular bacteria that occur in insects and filarial worms. Strains that infect insects have genomes that encode mobile genetic elements, including diverse lambda-like prophages called Phage WO. Phage WO packages an approximately 65 kb viral genome that includes a unique eukaryotic association module, or EAM, that encodes unusually large proteins thought to mediate interactions between the bacterium, its virus, and the eukaryotic host cell. The Wolbachia supergroup B strain, wStri from the planthopper Laodelphax striatellus, produces phage-like particles that can be recovered from persistently infected mosquito cells by ultracentrifugation. Illumina sequencing, assembly, and manual curation of DNA from two independent preparations converged on an identical 15,638 bp sequence that encoded packaging, assembly, and structural proteins. The absence of an EAM and regulatory genes defined for Phage WO from the wasp, Nasonia vitripennis, was consistent with the possibility that the 15,638 bp sequence represents an element related to a gene transfer agent (GTA), characterized by a signature head–tail region encoding structural proteins that package host chromosomal DNA. Future investigation of GTA function will be supported by the improved recovery of physical particles, electron microscopic examination of potential diversity among particles, and rigorous examination of DNA content by methods independent of sequence assembly.

  PublisherOA PDFDOI

• Establishment of a new cell line from embryos of the mosquito, Culex pipiens

  In Vitro Cellular & Developmental Biology - Animal · 2023-05-03 · 2 citations

  article1st authorCorresponding
  PublisherDOI

• Mitotically inactivated mosquito cells support robust Wolbachia infection and replication

  In Vitro Cellular & Developmental Biology - Animal · 2022-10-01 · 3 citations

  article1st authorCorresponding
  PublisherDOI

• Muramidase, nuclease, or hypothetical protein genes intervene between paired genes encoding DNA packaging terminase and portal proteins in Wolbachia phages and prophages

  Virus Genes · 2022 · 8 citations

  1st authorCorresponding
  • Biology
  • Genetics
  PublisherDOI

Recent grants

• NIH Grant R01AI043971

  NIH · $475k · 2002

• NIH Grant R01AI036258

  NIH · $1.5M · 2004

• NIH Grant R21AI070913

  NIH · $383k · 2009

• NIH Grant R01AI020385

  NIH · $3.7M · 2006

• Optimizing Wolbachia manipulation in mosquito cell lines

  NIH · $1.6M · 2009–2016

Frequent coauthors

• Anna Gerenday

  University of Minnesota

  15 shared

• Gerald D. Baldridge

  University of Minnesota

  14 shared

• Michio Nomura

  Kyoto University

  13 shared

• Vida P. Hernandez

  University of Minnesota

  12 shared

• G.R. Wyatt

  10 shared

• S. Richard Jaskunas

  10 shared

• Henry H. Hagedorn

  University of Arizona

  9 shared

• Bill G. Williams

  9 shared

Labs

• Fallon LabPI

Awards & honors

• University of Minnesota Distinguished McKnight University Pr…
• Invited Visiting Professor, Central China Normal University,…
• Semester leave: University of Texas Medical Branch, Departme…
• University of Minnesota, Distinguished Women Scholars Award…
• FAME (Faculty Award for Mentorship in Entomology) Award, U.…