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- Creators: Barrett, The Honors College
- Status: Published
Description
Virtually all animals require relatively predictable developmental schedules in order to fulfill the cycle of life. Cell death and severe inflammation alter steroid hormone production and can disrupt the timing of developmental transitions such as puberty. In the fruit fly, Drosophila melanogaster, injury to wing precursor tissues has been shown to result in decreased steroid hormone levels and delay development. The effects of damage to other tissues have not yet been explored. Here, the larval salivary glands were damaged in order to observe how injuring these specific tissues affect the timing of developmental transitions. Damage was induced by tissue-specific, temperature sensitive activation of cell death genes. The results indicated that death to salivary gland cells accelerates the Drosophila time to adult eclosion and that the observed acceleration of development is age-dependent. Insight into the effects of injury on development in Drosophila can potentially lead to information about development in other organisms, including humans, following injury or chronic inflammation.
ContributorsRippere, Alicia Leann (Author) / Hackney, Jennifer (Thesis director) / Marshall, Pamela (Committee member) / Barrett, The Honors College (Contributor) / School of Mathematical and Natural Sciences (Contributor)
Created2015-05
Description
In this paper, I aim to assess the ethical and policy issues at the forefront of developmental biology, mainly, the 14-day guideline dictating human embryo research. Ever since the invention of in vitro fertilization in the 1970s, the research landscape of human embryo research has been well explored. Now, there are new embryonic technologies and human embryonic stem cell based models that many believe do not fit into current guidelines. This paper analyzes four of these new technologies-- stem cell derived gametes, embryoids, 3D printed embryos and synthetic embryos-- in order to explore the impetus for reopening the debate on the 14-day guideline. The paper then explores current research and research projects while comparing and contrasting science as well as the potential for moral status and how that impacts regulation. Current United States policies and regulations as well as current professional society guidelines are broken down to fully grasp the political landscape surrounding human embryo research. Notably, current policies include the complete lack of a federal definition of an embryo as well as the Dickey-Wicker Amendment which restrict funding for human embryo research. It is thus advised that these, along with the 14 day guideline, are updated in order to encapsulate the early human developmental research landscape and promote research. This paper ends with an in depth policy recommendation including (but not limited to) bill language, suggested definitions and potential strategies.
ContributorsNadone, Haley (Author) / Robert, Jason (Thesis director) / Frow, Emma (Committee member) / School of Life Sciences (Contributor) / School of Politics and Global Studies (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Forensic entomology is the use of insects in legal investigations, and relies heavily upon calculating the time of colonization (TOC) of insects on remains using temperature-dependent growth rates. If a body is exposed to temperatures that exceed an insect’s critical limit, TOC calculations could be severely affected. The determination of critical thermal limits of forensically-relevant insects is crucial, as their presence or absence could alter the overall postmortem interval (PMI) calculation. This study focuses on the larvae of Phormia regina (Meigen) (Diptera: Calliphoridae), a forensically relevant blow fly common across North America. Three populations were examined (Arizona, Colorado, and New Jersey), and five day old larvae were exposed to one of two temperatures, 39℃ or 45℃, for five hours. Across all colonies, the survival rate was lower at 45℃ than 39℃, in both larval and emerged adult stages. The Arizona colony experienced a harsher drop in survival rates at 45℃ than either the Colorado or New Jersey colonies. This research suggests that the range of 39℃ - 45℃ approaches the critical thermal limit for P. regina, but does not yet exhibit a near or complete failure of survivorship that a critical temperature would cause at this duration of time. However, there is opportunity for further studies to examine this critical temperature by investigating other temperatures within the 39℃ - 45℃ range and at longer durations of time in these temperatures.
ContributorsMcNeil, Tara (Author) / Weidner, Lauren (Thesis director) / Meeds, Andrew (Committee member) / Barrett, The Honors College (Contributor) / School of Humanities, Arts, and Cultural Studies (Contributor) / School of Mathematical and Natural Sciences (Contributor)
Created2022-05
Description
Damage to the central nervous system due to spinal cord or traumatic brain injury, as well as degenerative musculoskeletal disorders such as arthritis, drastically impact the quality of life. Regeneration of complex structures is quite limited in mammals, though other vertebrates possess this ability. Lizards are the most closely related organism to humans that can regenerate de novo skeletal muscle, hyaline cartilage, spinal cord, vasculature, and skin. Progress in studying the cellular and molecular mechanisms of lizard regeneration has previously been limited by a lack of genomic resources. Building on the release of the genome of the green anole, Anolis carolinensis, we developed a second generation, robust RNA-Seq-based genome annotation, and performed the first transcriptomic analysis of tail regeneration in this species. In order to investigate gene expression in regenerating tissue, we performed whole transcriptome and microRNA transcriptome analysis of regenerating tail tip and base and associated tissues, identifying key genetic targets in the regenerative process. These studies have identified components of a genetic program for regeneration in the lizard that includes both developmental and adult repair mechanisms shared with mammals, indicating value in the translation of these findings to future regenerative therapies.
ContributorsHutchins, Elizabeth (Author) / Kusumi, Kenro (Thesis advisor) / Rawls, Jeffrey A. (Committee member) / Denardo, Dale F. (Committee member) / Huentelman, Matthew J. (Committee member) / Arizona State University (Publisher)
Created2015