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- Creators: School of Life Sciences
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Bermuda Land Snails make up a genus called Poecilozonites that is endemic to Bermuda and is extensively present in its fossil record. These snails were also integral to the creation of the theory of punctuated equilibrium. The DNA of mollusks is difficult to sequence because of a class of proteins called mucopolysaccharides that are present in high concentrations in mollusk tissue, and are not removed with standard DNA extraction methods. They inhibit Polymerase Chain Reactions (PCRs) and interfere with Next Generation Sequencing methods. This paper will discuss the DNA extraction methods that were designed to remove the inhibitory proteins that were tested on another gastropod species (Pomacea canaliculata). These were chosen because they are invasive and while they are not pulmonates, they are similar enough to Bermuda Land Snails to reliably test extraction methods. The methods that were tested included two commercially available kits: the Qiagen Blood and Tissue Kit and the Omega Biotek Mollusc Extraction Kit, and one Hexadecyltrimethylammonium Bromide (CTAB) Extraction method that was modified for use on mollusk tissue. The Blood and Tissue kit produced some DNA, the mollusk kit produced almost none, and the CTAB Extraction Method produced the highest concentrations on average, and may prove to be the most viable option for future extractions. PCRs attempted with the extracted DNA have all failed, though it is likely due to an issue with reagents. Further spectrographic analysis of the DNA from the test extractions has shown that they were successful at removing mucopolysaccharides. When the protocol is optimized, it will be used to extract DNA from the tissue from six individuals from each of the two extant species of Bermuda Land Snails. This DNA will be used in several experiments involving Next Generation Sequencing, with the goal of assembling a variety of genome data. These data will then be used to a construct reference genome for Bermuda Land Snails. The genomes generated by this project will be used in population genetic analyses between individuals of the same species, and between individuals of different species. These analyses will then be used to aid in conservation efforts for the species.
Today, some modern zoos, aquariums, and similar animal-exhibiting institutions continue to shift their priorities toward a focus on the conservation of wildlife. Conservation challenges span a broad subject area. The focus that any institution chooses can vary greatly in terms of magnitude and measures of significance. Many modern zoos often choose to make global conservation a central institutional priority: conservation of biodiversity, habitat protection, species extinction, and more. Some institutions, however, set conservation priorities on a smaller scale, focusing on contributions that have a more indirect effect on wild species and habitats, such as the welfare of populations in captivity, raising public awareness of conservation missions, and conservation education. By comparing the institutional priorities of two organizations within the Association of Zoos and Aquariums (AZA), the Arizona-Sonora Desert Museum and the Phoenix Zoo, I explore how each institution manages its living collections and works toward its respective conservation mission. I interviewed members of each institution and analyzed the similarities and differences between the organizations based on their management of living collections, and how different mission statements might shape their work. This included investigating the focus each institution has on animal welfare, in situ and ex situ conservation, and maintaining public interest. This also required defining what conservation and welfare mean to each institution and how that affects the management of their living collections. From a literature review and interviews with representatives from each institution, I was able to determine that despite any differences in style or in the language of respective mission statements, each institution prioritizes connecting the public and conservation of biodiversity. While they employ different approaches - one institution takes a regional interest in the Sonoran Desert ecosystem and landscape; the other takes a more global approach to its experiences, exhibits, and collections - the core values and ultimately the vision remain the same. Conservation may serve as the primary motivator for both the Museum and the Zoo, but my thesis is that this rationale could not be realized by itself for these institutions. Rather, conservation as a core value relies upon the support of other critical institutional priorities working together. In this way animal welfare, public engagement, and conservation relate to one another as institutional values and create the impact that the zoo and museum have on their local communities, as well as on conservation as a whole.
receptor (RAR) and vitamin D receptor (VDR). The RXR/RAR dimer is activated by ligand all
trans retinoic acid (ATRA), which culminates in gut-specific effector T cell migration. Similarly,
the VDR/RXR dimer binds 1,25(OH)2D3 to cause skin-specific effector T cell migration.
Targeted migration is a potent addition to current vaccines, as it would induce activated T cell
trafficking to appropriate areas of the immune system and ensure optimal stimulation (40).
ATRA, while in use clinically, is limited by toxicity and chemical instability. Rexinoids
are stable, synthetically developed ligands specific for the RXR. We have previously shown that
select rexinoids can enhance upregulation of gut tropic CCR9 receptors on effector T cells.
However, it is important to establish whether these cells can actually migrate, to show the
potential of rexinoids as vaccine adjuvants that can cause gut specific T cell migration.
Additionally, since the RXR is a major contributor to VDR-mediated transcription and
epidermotropism (15), it is worth investigating whether these compounds can also function as
adjuvants that promote migration by increasing expression of skin tropic CCR10 receptors on T
cells.
Prior experiments have demonstrated that select rexinoids can induce gut tropic migration
of CD8+ T cells in an in vitro assay and are comparable in effectiveness to ATRA (7). The effect
of rexinoids on CD4+ T cells is unknown however, so the aim of this project was to determine if
rexinoids can cause gut tropic migration in CD4+ T cells to a similar extent. A secondary aim
was to investigate whether varying concentrations in 1,25-Dihydroxyvitamin D3 can be linked to
increasing CCR10 upregulation on Jurkat CD4+ T cells, with the future aim to combine 1,25
Dihydroxyvitamin D3 with rexinoids.
These hypotheses were tested using murine splenocytes for the migration experiment, and
human Jurkat CD4+ T cells for the vitamin D experiment. Migration was assessed using a
Transwell chemotaxis assay. Our findings support the potential of rexinoids as compounds
capable of causing gut-tropic migration in murine CD4+ T cells in vitro, like ATRA. We did not
observe conclusive evidence that vitamin D3 causes upregulated CCR10 expression, but this
experiment must be repeated with a human primary T cell line.