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The two tarantula species used in this study were Grammostola rosea, found in Chile, and Haplopelma lividum, found in Africa. As tarantulas become more common in the pet trade, questions about the effects and components of their venom have arisen. Many types of venom are known to contain toxins with pharmacological action. However, the exact mode of action of tarantula venom is unknown. To address the hypothesis that the two tarantula species would have different teratogenicity based on their different evolutionary histories, venom was collected from tarantulas housed in similar conditions. The venom was stored at −20°C until used. A 96-hr frog embryo assay with 20 embryos was performed to determine the LC50 (lethal), EC50 (malformation), and growth effects. Venom concentrations ranged from 0-0.2% (v/v). Mortality, malformation, and length were analyzed using Tox Tools and SYSTAT software. The Grammostola rosea venom had a 96-hr LC50 of 0.101% (v/v) and an EC50 of 0.0963% (v/v). It also resulted in a consistent spinal malformation and reduction of embryo growth. The Haplopelma lividum venom had a 96-hr LC50 of 0.0713% (v/v) and an EC50 >> 0.075% v/v.
The faithful alignment and segregation of chromosomes during mitosis is essential for the prevention of aberrant chromosome numbers that can lead to cancer. This process is mediated by the mitotic spindle, which forms stable attachments to the chromosomal centromere through the kinetochore structural intermediate. Small kinetochore-associated protein (SKAP) is a recently described component to the kinetochore that complexes with other kinetochore-associated proteins including astrin, CENP-E, and CEP55. SKAP is required for proper chromosome segregation and the metaphase to anaphase transition as its depletion results in activation of the spindle assembly checkpoint and mitotic delay. Here, we show that overexpression of SKAP in cultured cells speeds cell division in a colony formation assay. We also show that SKAP along with the interacting proteins CEP55 and astrin are overexpressed in human breast carcinoma. These data suggest that aberrant overexpression of SKAP and the astrin-SKAP complex may help facilitate the rapid growth of tumor cells.
Adjuvants are added to a vaccine to enhance the antibody response to the antigen. A number of different materials have been used as adjuvants. In this study, mice were immunized with ovalbumin plus one of three adjuvants: Freund's complete adjuvant (FCA), Freund's incomplete adjuvant (FIA), or alum. Control mice received no vaccine. FCA is generally considered the strongest adjuvant and alum the weakest, but use of FCA is often avoided due to concerns over negative effects on the animals. All mice that received an adjuvant/antigen vaccination produced high levels of antibodies to ovalbumin, whereas no control mice did. Levels of anti-ovalbumin antibodies were not significantly different between groups that received FCA, FIA, or alum. Of the three adjuvants tested, alum is the most cost-effective and possibly the safest for the animal. This, coupled with the results of this study, suggest that it is the most practical of the three tested adjuvants, at least in conjunction with ovalbumin as an antigen. However, different antigens may require different adjuvants, and a general recommendation would require further testing.
Corticosterone (CORT) belongs to a family of steroid hormones known as the glucocorticoids. CORT is produced in vivo in response to physical and psychological stress and has immunosuppressive qualities. As an immunosuppressant, CORT alters the frequency of immune cells in lymphoid organs. This study quantified the effects of exogenous CORT on splenic CD8 T cells in mice. CD8 T cells are critical for destruction of virally infected and tumorigenic host cells. Thus, it is important to determine the timing by which CORT alters the frequency of CD8 T cells. CORT was administered in the drinking water of C57BL/6 mice for time intervals ranging from 12-120 hours. Following treatment, spleens were harvested and processed, total splenocytes were counted, and CD8 T cells were quantified by flow cytometry. Spleens from mice treated with CORT were significantly smaller than spleens from untreated mice following just 12 hours of exposure to CORT. A marked decline in both naïve (CD44lo) and activated (CD44hi) CD8 T cells was observed. This loss of CD8 T cells was greater the longer the mice were treated with CORT. Flow cytometric analysis suggests that this decrease in CD8 T cells was due, in part, to increased amounts of apoptosis in the spleen of CORT treated mice. These studies are important since glucocorticoids are used clinically to suppress unwanted immune responses and to control inflammation and other symptoms associated with radiation and chemotherapy treatments.
The ability of social insects such as ants to distinguish between nestmates and non-nestmates is odor-based, learned and critical to the survival of the colony. However, little is known about how the brain processes the olfactory cues associated with nestmate recognition. Previous studies have shown that inhibition of muscarinic acetylcholine receptors with a competitive inhibitor, scopolamine affects nestmate recognition in honeybees, causing them to mistakenly attack nestmates. This suggests that muscarinic receptors may be required for either olfaction and/or retrieval of odor memory. The aim of this study was to further investigate the role of muscarinic receptors in nestmate recognition in another social insect, the harvester ant (Pogonomyrmex barbatus). Focal ants were fed either scopolamine dissolved in sucrose or sucrose alone (control) for approximately 72 hours, then placed in an arena with either a nestmate or a genetically unrelated non-nestmate. We videotaped their interactions and determined the frequency with which focal ants exhibited aggressive behaviors toward the introduced ants. Focal ants treated with scopolamine exhibited inappropriate aggressive behaviors toward nestmates with a significantly higher frequency than did the controls, but with the same frequency that they exhibited aggressive behaviors toward non-nestmates. These results suggest that scopolamine-treated ants can't distinguish nestmates from non-nestmates. However, scopolamine-treated focal ants did respond appropriately to the presence of an olfactory repellent, indicating that scopolamine does not disrupt olfaction. The data support a role for muscarinic receptors in odor memory retrieval rather than in odor perception, and indicate that this role is conserved in P. barbatus.
Surveillance and tracking of antibiotic resistant bacteria carried on common-use items will help to elucidate the prevalence of antibiotic resistance within communities. Communication of these data will allow healthcare agencies and basic researchers to better plan mechanisms for combatting the problem of antibiotic resistance. During this project, samples were collected from public access computer keyboards and personal cell phones of the faculty, staff, and students at Troy University in Troy, Alabama. From these samples, thirty-eight individual isolates were identified by biochemical testing; one sample could not be identified. Nine distinct organisms were identified to the species level and included both gram positive and gram negative bacteria. Each of the 39 isolates was tested for resistance to 17 antibiotics. Resistance to three β-lactams (ampicillin, oxacillin [methicillin], and penicillin) was most common while overall drug resistance remained low. β-lactam antibiotics are commonly used to treat a wide range of bacterial infections. Oxacillin is one of the “last ditch” antibiotics within the β-lactam family and is used for serious bacterial infections. With the overuse and misuse of antibiotics, drug and multi-drug resistance among commonly encountered bacteria is expected to rise.
To assess effects of maternal separation on later aggressive and reproductive behaviors, male Sprague-Dawley pups were separated from their mothers every other day for 8 h (long-term separation; LTS), 4 h (short term separation; STS), or 0 h (no separation; NS) from post-natal day 2 through 20. Maternal behaviors, including lactation performance, nest building, grouping, and hovering over pups were measured during the separation period. At maturity, aggressive behavior of male subjects was assessed. Subjects were also mated to novel females and reproductive outcomes measured. It was hypothesized that male pups periodically separated from their mothers would demonstrate increased aggression and decreased reproductive success as adults. Contrary to expectations, maternal separation did not affect later adult aggressive behavior or reproductive outcomes. Additional studies examining the role of the neonatal environment in shaping subsequent male behavior are needed.
Castor bean (Ricinus communis L.) relies on seed dispersal by attracting ants with elaiosomes; lipid rich seed appendages, which serve as a source of food for ant larvae. Additionally, castor bean petioles and inflorescences have extra floral nectary (EFN) glands that secrete sugars that also attract ants, which in return, defend against herbivores. We propose that in order to attract ants, castor bean would have to balance allocation of energy toward plant defense and seed dispersal per the Principle of Allocation. Specifically, we hypothesized that in castor bean, an increase in elaiosome size would correspond to result in a decrease in EFN gland size. We examined proportion of elaiosome:seed (by weight) investment relative to the EFN gland size on a given castor bean plant. We found that elaiosome weight was not correlated with EFN gland area (p = 0.1542), and report a one to five fold range in elaiosome investment across 34 plants. We present a range of environmental factors contributing to the observed variation in elaiosome investment.
The National Executive Committee is pleased to announce the recipients of the TriBeta Research Grants for 2012. The total amount awarded was $57,200.00. Grants ranged from $300 to $1200. Below are the grant winners and the schools they represent.
The following chapters have sent in officer slates for 2013-2014. Officers are listed in the order of President, Vice President, Secretary, Treasurer, Historian, and Faculty Advisor unless otherwise noted. The chapters are listed alphabetically by Greek name. Please submit new slates, changes and corrections to Lori.Kelman@montgomerycollege.edu.