Selection for Increased Starvation Resistance Using Drosophila melanogaster: Investigating Physiological and Life History Trait Responses to Starvation and Dietary Supplementation in the Context of an Obese Phenotype

Artificial selection for starvation resistance provided insight into the relationships between evolved physiological and life history trait responses following exposure to biologically induced stress. Investigations of alterations to body composition, metabolic rate, movement, and life history traits including development time, female egg production, and longevity in response to brief periods of starvation were conducted on genetically based starvation-resistant and control lines of Drosophila melanogaster. Analysis of the starvation-resistant lines indicated increased energy storage with increased triglyceride deposition and conversion of carbohydrates to lipid, as identified by respiratory quotient values. Correlations between reductions in metabolic rates and movement in the starvation-resistant lines, suggested the presence of an evolved physiological response resulting in energy conservation. Investigations of life history traits in the starvation-resistant lines indicated no significant differences in development time or reproduction between the selected and control lines. Measurements of longevity, however, indicated a significant reduction in starvation-resistant D. melanogaster lifespan. These results suggested that elevated lipid concentrations, similar to that observed with obesity, were correlated with premature mortality. Exposure of the starvation-resistant and control lines to diets supplemented with glucose, palmitic acid, and a 2:1 mixture of casein to albumin were used to investigate alterations in body composition, movement, and life history traits. Results obtained from this study indicated that increased sugar in the diet led to increased carbohydrate, glycogen, total sugar, trehalose, and triglyceride concentrations, while increased fat and protein in the diet resulted in increased soluble protein, carbohydrate, glycogen, total sugar, and trehalose concentrations. Examination of life history trait responses indicated reduced fecundity in females exposed to increased glucose concentrations. Increased supplementations of palmitic acid was consistently correlated with an overall reduction in lifespan in both the starvation-resistant and control Drosophila lines, while measurements of movement indicated increased female activity levels in flies exposed to diets supplemented with fat and protein. Analyses of the physiological and life history trait responses to starvation and dietary supplementation on Drosophila melanogaster used in the present study has implications for investigating the mechanisms underlying the development and persistence of human obesity and associated metabolic disorders.

Physiological Studies on Candida albicans

Candida albicans is a common opportunistic, dimorphic human fungal pathogen. One of its virulence factors is the morphological switch between yeasts and hyphal or pseudohyphal forms, which can invade tissues and cause damage. Our studies focus on factors regulating pseudohyphae and epigenetic modifications of C. albicans. Regulating factors of pseudohyphae are aromatic alcohols and high phosphate. At low concentrations, exogenous aromatic alcohols induced pseudohyphae, as did high phosphate. For addressing the pathways involved in inducing pseudohyphae by aromatic alcohols or high phosphate, we used mutants defective in cAMP dependent PKA pathway (efg1/efg1), MAP kinase pathway (cph1/cph1), or both (cph1/cph1/efg1/efg1). These mutants failed to produce either hyphae or pseudohyphae in the presence of aromatic alcohols; but high phosphate still stimulated pseudohyphae. Gcn4, a transcription activator of more than 500 amino acid related genes, is turned-on in response to amino acid starvation. The accumulation of aromatic alcohols sends nitrogen starvation signals, which inhibit eIF2B, which in turn derepresses Gcn4p. High phosphate also induces pseudohyphae by derepressing Gcn4p, although the pathways involved are still unknown. In sum, aromatic alcohols and high phosphate induce pseudohyphae by derepressing Gcn4. In this study we found a novel posttranslational histone modification in C. albicans, which is biotinylation. Western blot and Mass spectrometry techniques were used to find that Histones H2B and H4 were biotinylated at every condition tested such as yeast vs. hyphae, aerobic growth vs. anaerobic growth, rich medium vs. defined medium. In C. albicans lysines K8, K11 in histone H4 and lysines K17, K18, K31 in histone H2B are biotin attachment sites as found using mass spectrometry. Biotin was also found to enhance the germ tube formation of C. albicans. Germ tube formation assays with biotin-starved cells as inoculum showed low percent of germ tubes (1-5%). Addition of biotin to the media showed 100% germ tubes. Biotinylation of histones were not detected from biotin-starved cells. Appendix-A details work related to Farnesol quantification assays in several strains of C.albicans and Ceratocystis ulmi, and growth studies of class E VPS strains of Saccharomyces Cerevisiae. Adviser: Kenneth W. Nickerson

Academentia: Physiological Stress, Toxic Work Sites and the Neutralization of Blackness by the Whiteness Standards of Professionalization

Using auto-ethnographic methods, supplementing by current race theories, along with interviews from other scholars, I regard academentia as a form of professionalism most readily communicable to academics of color seeking advance. It can also infect those whose embrace of blackness (widely defined across cultures) is the least tolerant of the racial designs of white cultural practices. Where in the interest of students and colleagues, such academics challenge the whiteness criteria defining academic success, most of their peers adhere to the racial standards of professionalism.

Pissing Glass and the Body Crass: Adaptations of the Scatological in Théophile

Examination of scatological motifs in Théophile de Viau’s (1590-1626) libertine, or ‘cabaret’ poetry is important in terms of how the scatological contributes to the depiction of the Early Modern body in the French lyric.1 This essay does not examine Théophile’s portrait of the body strictly in terms of the ‘Baroque’ or the ‘neo-Classical.’ Rather, it argues that the scatological context in which he situates the body (either his, or those of others), reflects a keen sensibility of the body representative of the transition between these two eras. Théophile reinforces what Bernard Beugnot terms the body’s inherent ‘eloquence’ (17), or what Patrick Dandrey describes as an innate ‘textuality’ in what the body ‘writes’ (31), and how it discloses meaning. The poet’s scatological lyric, much of which was published in the Pamasse Satyrique of 1622, projects a different view of the body’s ‘eloquence’ by depicting a certain realism and honesty about the body as well as the pleasure and suffering it experiences. This Baroque realism, which derives from a sense of the grotesque and the salacious, finds itself in conflict with the Classical body which is frequently characterized as elegant, adorned, and ‘domesticated’ (Beugnot 25). Théophile’s private body is completely exposed, and, unlike the public body of the court, does not rely on masking and pretension to define itself. Mitchell Greenberg contends that the body in late sixteenth-century and early seventeenth-century French literature is often depicted in a chaotic manner because, ‘the French body politic was rent by tumultuous religious and social upheavals’ (62).2 While one could argue that Théophile’s portraits of a syphilis-ridden narrators are more a reflection of his personal agony rather than that of France as a whole, what emerges in Théophile is an emphasis on the movement, if not decomposition of the body.3 Given Théophile’s public persona and the satirical dimension of his work, it is difficult to imagine that the degeneration he portrays is limited only to his individual experience. On a collective level, Théophile reflects what Greenberg calls ‘a continued, if skewed apprehension of the world in both its physical and metaphysical dimensions’(62–3) typical of the era. To a large extent, the body Théophile depicts is a scatological body, one whose deterioration takes the form of waste, disease, and evacuation as represented in both the private and public domain. Of course, one could cast aside any serious reading of Théophile’s libertine verse, and virtually all of scatological literature for that matter, as an immature indulgence in the prurient. Nonetheless, it was for his dissolute behavior and his scatological poetry that Théophile was imprisoned and condemned to death. Consequently, this part of his work merits serious consideration in terms of the personal and poetic (if not occasionally political) statement it represents. With the exception of Claire Gaudiani’s outstanding critical edition of Théophile’s cabaret lyric, there exist no extensive studies of the poet’s libertine œuvre.4 Clearly however, these poems should be taken seriously with respect to their philosophical and aesthetic import. As a consequence, the objective becomes that of enhancing the reader’s understanding of the lyric contexts in which Théophile’s scatological offerings situate themselves. Structurally, the reader sees how the poet’s libertine ceuvre is just that — an integrated work in which the various components correspond to one another to set forth a number of approaches from which the texts are to be read. These points of view are not always consistent, and Théophile cannot be thought of as writing in a sequential manner along the lines of devotional Baroque poets such as Jean de La Ceppède and Jean de Sponde. However, there is a tendency not to read these poems in their vulgar totality, and to overlook the formal and substantive unity in this category of Théophile’s work. The poet’s resistance to poetic and cultural standards takes a profane, if not pornographic form because it seeks to disgust and arouse while denigrating the self, the lyric other, and the reader. Théophile’s pornography makes no distinction between the erotic and scatological. The poet conflates sex and shit because they present a double form of protest to artistic and social decency while titillating and attacking the reader’s sensibilities. Examination of the repugnant gives way to a cathartic experience which yields an understanding of, if not ironic delight in, one’s own filthy nature.