IU Indianapolis ScholarWorks :: Browsing by Author "Owings, Charity G."

Browsing by Author "Owings, Charity G."

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Blow fly stable isotopes reveal larval diet: A case study in community level anthropogenic effects
(PLOS, 2021-04) Owings, Charity G.; Gilhooly, William P. III; Picard, Christine J.; Earth Sciences, School of Science
Response to human impacts on the environment are typically initiated too late to remediate negative consequences. We present the novel use of stable isotope analysis (SIA) of blow flies to determine human influences on vertebrate communities in a range of human-inhabited environments, from a pristine national park to a dense metropolitan area. The refrain “you are what you eat” applies to the dietary isotope record of all living organisms, and for carrion-breeding blow flies, this translates to the type of carcasses present in an environment. Specifically, we show that carnivore carcasses make up a large proportion of the adult fly’s prior larval diet, which contrasts to what has been reportedly previously for the wild adult fly diet (which consists of mostly herbivore resources). Additionally, we reveal the potential impact of human food on carcasses that were fed on by blow flies, underscoring the human influences on wild animal populations. Our results demonstrate that using SIA in conjunction with other methods (e.g., DNA analysis of flies) can reveal a comprehensive snapshot of the vertebrate community in a terrestrial ecosystem.
Chemical Assay for the Detection of Vertebrate Fecal Metabolites in Adult Blow Flies (Diptera: Calliphoridae)
(Oxford, 2018-06-06) Owings, Charity G.; Skaggs, Christine; Sheriff, Winyu; Manicke, Nicholas; Picard, Christine J.; Department of Biology, School of Science
Filth flies are commonly implicated in pathogen transmission routes due to their affinity for vertebrate waste and their synanthropic associations. However, solidifying the link between flies and infected feces in the wild can be difficult, as interpretations made solely from microbial culturing or sequencing methods may represent an incomplete picture of pathogen acquisition. We present an analytical assay using high performance liquid chromatography tandem mass spectrometry (HPLC MS/MS) to detect vertebrate fecal metabolites (urobilinoids) in adult blow fly guts. Proof of concept experiments consisted of controlled feeding in which flies were grouped into three treatments (unfed, exposure to beef liver tissue, and exposure to canine feces; N = 20/treatment) using the black blow fly Phormia regina Meigen (Diptera: Calliphoridae). It was revealed that only feces-related samples exhibited peaks with an m/z of 591 and MS/MS spectra consistent with urobilinoids. These peaks were not seen for beef liver tissue, flies exposed to beef liver tissue, or unfed flies. Samples taken directly from beef liver tissue and from feces of several animals were also tested. To test this assay in wild flies, 216 flies were additionally analyzed to determine whether they had ingested vertebrate feces. About 13% of the wild flies exhibited these same peaks, providing a baseline measure of blow flies collected in urban and residential areas consuming feces from the environment. Overall, this assay can be used for P. regina collected in an applied setting and its integration with microbial culturing and sequencing methods will help to improve its use.
Female Blow Flies As Vertebrate Resource Indicators
(Springer Nature, 2019-07-22) Owings, Charity G.; Banerjee, Aniruddha; Asher, Travis M. D.; Gilhooly, William P.; Tuceryan, Anais; Huffine, Mary; Skaggs, Christine L.; Adebowale, Iyun M.; Manicke, Nicholas E.; Picard, Christine J.; Biology, School of Science
Rapid vertebrate diversity evaluation is invaluable for monitoring changing ecosystems worldwide. Wild blow flies naturally recover DNA and chemical signatures from animal carcasses and feces. We demonstrate the power of blow flies as biodiversity monitors through sampling of flies in three environments with varying human influences: Indianapolis, IN and two national parks (the Great Smoky Mountains and Yellowstone). Dissected fly guts underwent vertebrate DNA sequencing (12S and 16S rRNA genes) and fecal metabolite screening. Integrated Nested Laplace Approximation (INLA) was used to determine the most important abiotic factor influencing fly-derived vertebrate richness. In 720 min total sampling time, 28 vertebrate species were identified, with 42% of flies containing vertebrate resources: 23% DNA, 5% feces, and 14% contained both. The species of blow fly used was not important for vertebrate DNA recovery, however the use of female flies versus male flies directly influenced DNA detection. Temperature was statistically relevant across environments in maximizing vertebrate detection (mean = 0.098, sd = 0.048). This method will empower ecologists to test vertebrate community ecology theories previously out of reach due practical challenges associated with traditional sampling.
New Distribution Record for Lucilia cuprina (Diptera: Calliphoridae) in Indiana, United States
(Oxford University Press, 2018-07-01) Owings, Charity G.; Picard, Christine J.; Biology, School of Science
Determining range expansion for insect species is vital in order to evaluate their impact on new ecosystems and communities. This is particularly important for species which could be potentially harmful to humans or domestic animals. Lucilia cuprina Wiedemann (Diptera: Calliphoridae) can act as a facultative ectoparasite and has an extensive history as the primary inducer of sheep-strike in Australia, New Zealand, and Africa. We present here the first record of this species in Indiana, United States. Lucilia cuprina's range expansion northward in the United States may be indicative of changing environmental conditions conducive to the proliferation of this species into historically cooler climates. The presence of this species could significantly impact forensic death investigations utilizing dipteran larvae to estimate a minimum postmortem interval. If range expansion of this species is not taken into account by a forensic entomologist (especially if L. cuprina is not known previously in their region), an inaccurate minimum postmortem interval (PMIMIN) estimation may be made, given the differences in development times for both species. Therefore, the range expansion of this fly could have large impacts for many different entomological disciplines.
The oncometabolite L-2-hydroxyglutarate is a common product of dipteran larval development
(Elsevier, 2020-12) Mahmoudzadeh, Nader H.; Fitt, Alexander J.; Schwab, Daniel B.; Martenis, William E.; Nease, Lauren M.; Owings, Charity G.; Brinkley, Garrett J.; Li, Hongde; Karty, Jonathan A.; Sudarshan, Sunil; Hardy, Richard W.; Moczek, Armin P.; Picard, Christine J.; Tennessen, Jason M.; Biology, School of Science
The oncometabolite L-2-hydroxyglutarate (L-2HG) is considered an abnormal product of central carbon metabolism that is capable of disrupting chromatin architecture, mitochondrial metabolism, and cellular differentiation. Under most circumstances, mammalian tissues readily dispose of this compound, as aberrant L-2HG accumulation induces neurometabolic disorders and promotes renal cell carcinomas. Intriguingly, Drosophila melanogaster larvae were recently found to accumulate high L-2HG levels under normal growth conditions, raising the possibility that L-2HG plays a unique role in insect metabolism. Here we explore this hypothesis by analyzing L-2HG levels in 18 insect species. While L-2HG was present at low-to-moderate levels in most of these species (<100 pmol/mg; comparable to mouse liver), dipteran larvae exhibited a tendency to accumulate high L-2HG concentrations (>100 pmol/mg), with the mosquito Aedes aegypti, the blow fly Phormia regina, and three representative Drosophila species harboring concentrations that exceed 1 nmol/mg - levels comparable to those measured in mutant mice that are unable to degrade L-2HG. Overall, our findings suggest that one of the largest groups of animals on earth commonly generate high concentrations of an oncometabolite during juvenile growth, hint at a role for L-2HG in the evolution of dipteran development, and raise the possibility that L-2HG metabolism could be targeted to restrict the growth of key disease vectors and agricultural pests.
Temporal survey of a carrion beetle (Coleoptera: Silphidae) community in Indiana
(Indiana Academy of Science, 2015) Owings, Charity G.; Picard, Christine J.
Carrion beetles (Coleoptera: Silphidae) play an important role in vertebrate decomposition as they utilize carcasses to carry out their life cycles. These beetles represent novel models for behavioral ecology, and can act as important forensic indicators in death investigations. However, population and community dynamics of silphids in Indiana are currently outdated. The aim of this study is to update surveys of a single silphid community with high temporal resolution in order to explore diversity and abundance patterns over time. Beetles were collected from Purdue University multiple times (N = 13) over a period of seven months in order to assess population dynamics at a single site. A total of 1607 specimens constituting seven different species were collected. Species abundance over time and space changed dramatically, and only one species (Nicrophorus tomentosus Weber) was present in nearly all collections (eleven out of thirteen, June–October 2014). It was demonstrated that the community dynamics of silphids at a single site in Indiana aligns with previous studies in the state. Additionally, the community structure of this family appears to change drastically over time in the summer months.

Browsing by Author "Owings, Charity G."

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