Life Sciences Commons^™

Investigating The Role Of Small Noncoding Rnas In Vertebrate Anoxia Tolerance, Claire Louise Riggs

Dissertations and Theses

Very few vertebrates survive extended periods of time without oxygen. Entry into metabolic depression is central to surviving anoxia, which is supported by overall suppression of protein synthesis, yet requires increased expression of specific proteins. Studying the rapid and complex regulation of gene expression associated with survival of anoxia may uncover new mechanisms of cellular biology and transform our understanding of cells, as well as inform prevention and treatment of heart attack and stroke in humans. Small non-coding RNAs (sncRNAs) have emerged as regulators of gene expression that can be rapidly employed, can target individual genes or suites of genes, …

Mechanism Of Gene Regulation By Coding Polya Tracks, Laura Lea Arthur

Arts & Sciences Electronic Theses and Dissertations

Regulation of gene expression is essential for cellular development and survival. The great variety and complexity of regulatory mechanisms underscores this fact. Messenger RNA stability and translational efficiency are often key determinants of gene expression. mRNA surveillance pathways, discovered for their role in degradation of aberrant mRNA, are now known to be instrumental in the regulation of physiologically correct mRNA stability. Thus, the study of cis elements in a transcript that can induce mRNA surveillance pathways has become an area of particular interest.

Here I report on the mechanism of gene regulation by coding polyA tracks, defined as a sequence …

Chromatin Accessibility Dynamics In The Arabidopsis Root Epidermis And Endodermis During Cold Acclimation, Shawn Hoogstra

Electronic Thesis and Dissertation Repository

Understanding cell-type specific transcriptional responses to environmental conditions is limited by a lack of knowledge of transcriptional control due to epigenetic dynamics. Additionally, cell-type analyses are limited by difficulties in applying current technologies to single cell-types. A novel DNase-seq protocol and analysis procedure, deemed DNase-DTS, was developed to identify DHSs in the Arabidopsis epidermis and endodermis under control and cold acclimation conditions. Results identified thousands of DHSs within each cell-type and experimental condition. DHSs showed strong association to gene expression, DNA methylation, and histone modifications. A priori mapping of existing DNA binding motifs within accessible genes and the cold C-repeat/dehydration …

Transcriptomic Regulation Of Alternative Phenotypic Trajectories In Embryos Of The Annual Killifish Austrofundulus Limnaeus, Amie L. Romney

Dissertations and Theses

The Annual Killifish, Austrofundulus limnaeus, survives the seasonal drying of their pond habitat in the form of embryos entering diapause midway through development. The diapause trajectory is one of two developmental phenotypes. Alternatively, individuals can "escape" entry into diapause and develop continuously until hatching. The alternative phenotypes of A. limnaeus are a form of developmental plasticity that provides this species with a physiological adaption for surviving stressful environments. The developmental trajectory of an embryo is not distinguishable morphologically upon fertilization and phenotype is believed to be influenced by maternal provisioning within the egg based on observations of offspring phenotype …

Characterizing Mekk1: Candidate Behavioural Isolation Gene, Caryn Dooner

Electronic Thesis and Dissertation Repository

Behavioural isolation can occur due to divergence in aspects of courtship and mating, and can contribute to reproductive isolation. The purpose of this study is to determine how a gene, Mekk1, contributes to female rejection behaviour between D. melanogaster and D. simulans. Unique polymorphisms were identified within D. simulans Mekk1 that could contribute to behaviour, most of which are non-coding. Both transcripts of Mekk1 appear to be expressed at similar levels in D. simulans and D. melanogaster. These data also indicate that Mekk1 may be expressed in a specific region of the brain called the mushroom body, …

Ecological Epigenetics Of Avian Range Expansions, Holly J. Kilvitis

USF Tampa Graduate Theses and Dissertations

In light of human-mediated environmental change, a fundamental goal for biologists is to determine which phenotypic characteristics enable some individuals, populations or species to be more adept at coping with such change, while rendering others more vulnerable. Studying ongoing range expansions provide a unique opportunity to address this question by allowing documentation of how novel environments shape phenotypic variation on ecological timescales. At range-edges, individuals are exposed to strong selective pressures and population genetic challenges (e.g. bottlenecks and/or founder effects), which make genetic adaptation difficult. Nevertheless, certain species, such as the house sparrow (Passer domesticus), seem to thrive in their …

Use Of Hpc To Analyze Changes In Gene Expression During Fruit Fly Spermiogenesis, Sepideh Dadkhah, Douglas A. Harrison, Jeramiah J. Smith

Commonwealth Computational Summit

In the fruit fly, Drosophila melanogaster, JAK/STAT signaling during spermiogenesis is known to play a crucial role in the maintenance of stem cells of the testis. Recent studies in our lab have shown that activation of the JAK/STAT pathway in somatic cyst cells is also required for the later stages of spermiogenesis like individualization.

The main goal of this project is to characterize the events downstream of JAK/STAT signaling in spermiogenesis and more specifically to determine the mechanism by which JAK/STAT activation regulates individualization, a later stage in spermiogenesis where 64 individual spermatids are formed from a 64-interconnected spermatid …

Anaplasma Phagocytophilum Infection Modulates Expression Of Megakaryocyte Cell Cycle Genes Through Phosphatidylinositol-3-Kinase Signaling, Supreet Khanal, Hameeda Sultana, John D. Catravas, Jason A. Carlyon, Girish Neelakanta

Biological Sciences Faculty Publications

Anaplasma phagocytophilum, the agent of human granulocytic anaplasmosis infects neutrophils and other cells from hematopoietic origin. Using human megakaryocytic cell line, MEG-01, we show that expression of cell cycle genes in these cells are altered upon A. phagocytophilum infection. Expression of several cell cycle genes in MEG-01 cells was significantly up regulated at early and then down regulated at later stages of A. phagocytophilum infection. Lactate dehydrogenase (LDH) assays revealed reduced cellular cytotoxicity in MEG-01 cells upon A. phagocytophilum infection. The levels of both PI3KCA (p110 alpha, catalytic subunit) and PI3KR1 (p85, regulatory subunit) of Class …

Effect Assessment Of Tio2 Nanoparticles Exposure On Medicago By Monitoring Morphophysiology, Charles Towey

Mahurin Honors College Capstone Experience/Thesis Projects

In recent years titanium dioxide nanoparticles (TiO₂NPs) have been ingredients in everything from paints to cosmetics, and even in some kinds of food. This growth in use has resulted in a substantial increase in the amount of titanium released into the environment, which could have detrimental effects on nearby plant and animal life. Currently, the number of studies conducted on the effects of TiO₂NPs is quite small, especially when it comes to edible crops. Because of this lack of research data, this study has been designed to assess the effect of TiO₂ NPs exposure on …

Divergent Responses Of Larval And Juvenile Blue Mussels To Low Salinity Exposure, Melissa A. May

Electronic Theses and Dissertations

In this study, we compared the osmotic stress response of larval and juvenile blue mussels (Mytilus edulis) at the transcriptomic, metabolomic, and whole organism levels. Blue mussels inhabit coastal areas, where they face climate-induced reductions in nearshore salinity. Despite their ecological and economic importance, scientists do not fully understand the underlying transcriptomic and cellular mechanisms of the osmotic stress response in blue mussels or how the ability to respond to stress changes throughout development. Blue mussels spend the first weeks of life developing through several larval stages in the plankton. These early life history stages are more vulnerable …

Transcriptomic Analysis Of Maternally Provisioned Cues For Phenotypic Plasticity In The Annual Killifish, Austrofundulus Limnaeus, Amie L. Romney, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Background: Genotype and environment can interact during development to produce novel adaptive traits that support life in extreme conditions. The development of the annual killifsh Austrofundulus limnaeus is unique among vertebrates because the embryos have distinct cell movements that separate epiboly from axis formation during early development, can enter into a state of metabolic dormancy known as diapause and can survive extreme environmental conditions. The ability to enter into diapause can be maternally programmed, with young females producing embryos that do not enter into diapause. Alternately, embryos can be programmed to “escape” from diapause and develop directly by both maternal …

Transcriptome Analysis Reveals Potential Mechanisms Underlying Differential Heart Development In Fast- And Slow-Growing Broilers Under Heat Stress, Jibin Zhang, Carl J. Schmidt, Susan J. Lamont

Jibin Zhang

Immune Responses In Hibernating Little Brown Myotis (Myotis Lucifugus) With White-Nose Syndrome, Thomas M. Lilley, Jenni M. Prokkola, Elisabeth Jeanine Rogers, Sarah Gronsky, Allen Kurta, Deeann Reeder, Kenneth A. Field

Faculty Journal Articles

White-nose syndrome (WNS) is a fungal disease responsible for decimating many bat populations in North America. Pseudogymnoascus destructans (Pd), the psychrophilic fungus responsible for WNS, prospers in the winter habitat of many hibernating bat species. The immune response that Pd elicits in bats is not yet fully understood; antibodies are produced in response to infection by Pd, but they may not be protective and indeed may be harmful. To understand how bats respond to infection during hibernation, we studied the effect of Pd inoculation on the survival and gene expression of captive hibernating Myotis lucifugus with varying …

Age And Sex-Specific Effect Of Caloric Restriction On Circadian Clock And Longevity-Associated Gene Expression, Arten Andreyevich Astafev

ETD Archive

The rhythms in the expression of circadian clock genes are affected by calorie restriction (CR), a dietary paradigm known to increase lifespan. In our current study, we show that circadian rhythms are influenced by sex and the effects of CR are different between males and females. In particular, we found a group of clock genes which showed a sex-dependent difference in expression, as well as in response to CR (Rev-Erb α, Ror γ and both Cryptochromes: Cry1 and Cry2 genes). Two clock genes showed no difference in expression but their response to CR showed sexual dimorphism (Ror α and Rev-Erb …

Real-Time Quantitative Pcr To Demonstrate Gene Expression In An Undergraduate Lab, Abijeet Singh Mehta, Amit Singh

Biology Faculty Publications

The objective of this teaching note is to develop a laboratory exercise, which allows students to get a hands-on experience of a molecular biology technique to analyze gene expression. The short duration of the biology laboratory for an undergraduate curriculum is the biggest challenge with the development of new labs. An important part of cell biology or molecular biology undergraduate curriculum is to study gene expression. There are many labs to study gene expression in qualitative manner. The commonly used reporter gene expression studies are primarily qualitative. However, there is no hands-on experience exercise to quantitatively determine gene expression. Therefore, …

Small Noncoding Rna Expression During Extreme Anoxia Tolerance Of Annual Killifish (Austrofundulus Limnaeus) Embryos, Claire L. Riggs, Jason E. Podrabsky

Biology Faculty Publications and Presentations

Small noncoding RNAs (sncRNA) have recently emerged as specific and rapid regulators of gene expression, involved in a myriad of cellular and organismal processes. MicroRNAs, a class of sncRNAs, are differentially expressed in diverse taxa in response to environmental stress, including anoxia. In most vertebrates, a brief period of oxygen deprivation results in severe tissue damage or death. Studies on sncRNA and anoxia have focused on these anoxia-sensitive species. Studying sncRNAs in anoxia-tolerant organisms may provide insight into adaptive mechanisms supporting anoxia tolerance. Embryos of the annual killifish Austrofundulus limnaeus are the most anoxia-tolerant vertebrates known, surviving over 100 days …

Assessment Of The Function And Expression Pattern Of Auxin Response Factor B3 In The Model Legume Plant Medicago Truncatula, Miglena Revalska, Valya Vassileva, Grigor Zehirov, Sofie Goormachtig, Anelia Iantcheva

Turkish Journal of Biology

The phytohormone auxin is a critical signal molecule, regulating fundamental processes in plant growth and development, such as shaping the root and shoot architecture, organ patterning, and nodulation. Auxin regulates plant gene expression mainly through auxin response factors (ARFs), which bind to auxin response elements in the promoter, upstream of auxin-activated genes. Here we examine and assess the function and expression pattern of a gene described as an auxin response factor, containing a DNA-binding pseudobarrel and B3 DNA-binding domains, from Medicago truncatula (MtARF-B3). For the model legume species M. truncatula, stable transgenic plants with MtARF-B3 overexpression, downregulation, and transcriptional reporters …

Molecular Investigations Of The Somatic Embryogenesis Recalcitrancein The Cherry (Prunus Cerasus L.) Rootstock Cab 6p, Kaouther Ben Mahmoud, Emna Jedidi, Fabienne Delporte, Yordan Muhovski, Ahmed Jemmali, Philippe Druart

Turkish Journal of Biology

Somatic embryogenesis is a powerful tool for clonal propagation and plant breeding in many plant species, but its application is limited by the genotype response based on the interaction between gene expression and culture conditions. In this context, the recalcitrance of the nonembryogenic cherry rootstock Prunus cerasus cultivar CAB 6P was investigated via the analysis of the candidate genes PiABP19, Picdc2, and PiSERK3 in comparison with the embryogenic genotype Prunus incisa cultivar N°131. Semiquantitative RT-PCR was employed to assess the transcript level of these genes in leaf explants and derived calli of the two genotypes cultured on picloram-containing MS medium …