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Regulation of growth by TGF-B in Drosophila
Title
Regulation of growth by TGF-B in Drosophila.
Creator
Gesualdi, Scott C., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Key to our understanding of growth regulation in Drosophila would be discovering a ligand that could regulate steroid synthesis. Activins are involved in regulating steroid hormone release in vertebrates. In invertebrates, they most likely function to keep ecdysone levels low to allow the larvae more time to achieve critical weight in order to initiate the metamorphic process. TGF-B(Transforming Growth Factor Beta) is a family of cytokine growth factors. We find that two members of the TGF-B...
Show moreKey to our understanding of growth regulation in Drosophila would be discovering a ligand that could regulate steroid synthesis. Activins are involved in regulating steroid hormone release in vertebrates. In invertebrates, they most likely function to keep ecdysone levels low to allow the larvae more time to achieve critical weight in order to initiate the metamorphic process. TGF-B(Transforming Growth Factor Beta) is a family of cytokine growth factors. We find that two members of the TGF-B signaling pathway Drosophila Activin (dACT) and Activin-like ligand Dawdle (DAW) signal through the type I receptor Baboon (BABO) and the type II receptor PUNT to primarily activate the transcription factor dSMAD2 and MAD to a lesser extent. One transcription factor brinker (brk) appears to be central to dACT signaling., In wings dACT signaling is necessary to promote growth however, dACT is not expressed in wings suggesting that dACT is provided through the endocrine system. One possible target tissue of dACT signaling is the ring gland (RG), which synthesizes and secretes the steroid hormone ecdysone (E). Consistent with this idea, using the UAS/GAL-4 system, we find that over-expression of the TGF-B ligand dACT with the neuroendocrine driver 386Y-GAL4 results in an increase in the size of flies. Surprisingly, when we increase the dose with two copies of dACT, it decreases the size of flies also indicating non-autononomous effects. We find that overexpression of the activated form of the dACT type I receptor Baboon (BABO) or brk with the ring gland specific driver phm-GAL4 results in developmental arrest of larvae that stay small and never pupate. The developmental arrest can be overcome by feeding larvae E, suggesting that dACT represses E through brk. These results suggest a model where dACT signaling activates brk which inhibits E. We picked three cytochrome P450 enzymes: phantom (PHM), disembodied (DIS) and spookier (SPKR)., PHM is not regulated by any component in the dACT signaling pathway however, we find DIS and SPKR are down-regulated through brk. MAD and dSmad2 bind to a Smad binding site and MAD out-competes dSMAD2. We find no evidence that Drosophila insulin-like peptides (DILPS)/PI3- Kinase or Ras signal through the dActivin signaling pathway.
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Date Issued
2009
PURL
http://purl.flvc.org/FAU/228773
Subject Headings
Cell differentiation, Developmental genetics, Integrins, Cellular control mechanisms
Format
Document (PDF)
Understanding the role of transgenic catalase in T-cell development in murine-based studies
Title
Understanding the role of transgenic catalase in T-cell development in murine-based studies.
Creator
Smith, Richard M., Harriet L. Wilkes Honors College
Abstract/Description
The thymus provides a unique microenvironment that facilitates T lymphocytes differentiation and maturation. However, the thymus atrophies after puberty which leads to an overall expression of metabolism gene pathways and low gene expression of certain peroxide scavenger enzymes such as catalase in thymic stromal compartments. From this data, we postulate that thymic stromal cells are highly susceptible to oxidative damage. We utilized a transgenic mice model overexpressing human catalase...
Show moreThe thymus provides a unique microenvironment that facilitates T lymphocytes differentiation and maturation. However, the thymus atrophies after puberty which leads to an overall expression of metabolism gene pathways and low gene expression of certain peroxide scavenger enzymes such as catalase in thymic stromal compartments. From this data, we postulate that thymic stromal cells are highly susceptible to oxidative damage. We utilized a transgenic mice model overexpressing human catalase targeted to the mitochondria (mCat) to test our hypothesis that gerater oxidative protection should lower the degree of thymus atrophy. Our experiment focused on a direct comparison of organ weights (thymus, kidney, lymph nodes, spleen and heart), cellularity and histology between transgenic and wildtype mice. We found that mCat had selective increases in thymus size.
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Date Issued
2012
PURL
http://purl.flvc.org/FAU/3359325
Subject Headings
T cells, Differentiation, Developmental genetics, Gene expression, Human cell culture, Thymus, Physiology
Format
Document (PDF)
Development of a novel assay for in vivo screening of neuromodulatory drugs and targeted disruption of cholinergic synaptic transmission in Drosophila melanogaster
Title
Development of a novel assay for in vivo screening of neuromodulatory drugs and targeted disruption of cholinergic synaptic transmission in Drosophila melanogaster.
Creator
Mejia, Monica, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Finding novel compounds that affect neuronal or muscular function is of great interest, as they can serve as potential pharmacological agents for a variety of neurological disorders. For instance, conopeptides have been developed into powerful drugs like the painkiller PrialtTM. Most conopeptides, however, have yet to be characterized, revealing the need for a rapid and straightforward screening method. We have designed a novel bioassay, which allows for unbiased screening of biological...
Show moreFinding novel compounds that affect neuronal or muscular function is of great interest, as they can serve as potential pharmacological agents for a variety of neurological disorders. For instance, conopeptides have been developed into powerful drugs like the painkiller PrialtTM. Most conopeptides, however, have yet to be characterized, revealing the need for a rapid and straightforward screening method. We have designed a novel bioassay, which allows for unbiased screening of biological activity of compounds in vivo against numerous molecular targets on a wide variety of neurons and muscles in a rapid and straightforward manner. For this, we paired nanoinjection of compounds with electrophysiological recordings from the Giant Fiber System of Drosophila melanogaster, which mediates the escape response of the fly.
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Date Issued
2013
PURL
http://purl.flvc.org/fcla/dt/3362560
Subject Headings
Drosophila melanogaster, Genetics, Drosophila melanogaster, Life cycles, Insects, Physiology, Developmental neurobiology, Neural transmission, Cholinergic mechanisms
Format
Document (PDF)
Genetic differentiation among populations of bald eagles, Haliaeetus leucocephalus
Title
Genetic differentiation among populations of bald eagles, Haliaeetus leucocephalus.
Creator
Helmick, Ericka Elizabeth., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
The bald eagle, Haliaeetus leucocephalus, population declined dramatically in the early 20th century reducing the population from tens of thousands of birds within the lower 48 states, to
Show moreThe bald eagle, Haliaeetus leucocephalus, population declined dramatically in the early 20th century reducing the population from tens of thousands of birds within the lower 48 states, to <450 pairs of birds, effectively inducing a population bottleneck. The overall population has recovered and was removed from the endangered species list in 2007. This study investigates whether such overall population statistics are appropriate descriptors for this widespread species. I investigated the genetic differentiation between three populations of bald eagles from Alaska, North Florida and Florida Bay using both mitochondrial and nuclear DNA loci to determine whether discrete subpopulations comprise the broad range. Significant FST values, for both mtDNA and microsatellites, were found between both Florida populations and Alaska, but not within Florida populations. Results indicate that there is strong population structure, rejecting the null hypothesis of a panmictic population. Future conservation efforts should focus on subpopulations rather than the overall population.
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Date Issued
2011
PURL
http://purl.flvc.org/FAU/3171395
Subject Headings
Wildlife conservation, Birds, Molecular genetics, Gene targeting, Developmental biology, Biochemical markers
Format
Document (PDF)
Plasma Steroid Hormones in Loggerhead and Green Sea Turtle Hatchlings
Title
Plasma Steroid Hormones in Loggerhead and Green Sea Turtle Hatchlings.
Creator
Reis, Andrea, Milton, Sarah L., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Florida’s sea turtle populations are increasing due to conservation efforts; however, sea turtle species are vulnerable to climate change. Turtles exhibit temperaturedependent sex determination, in which nest environment influences sex. Environmental changes may produce altered sex ratios that limit reproduction potential; therefore hatchling sex ratios should be monitored. Hatchlings are not externally sexually dimorphic, making sex identification difficult. This study established baseline...
Show moreFlorida’s sea turtle populations are increasing due to conservation efforts; however, sea turtle species are vulnerable to climate change. Turtles exhibit temperaturedependent sex determination, in which nest environment influences sex. Environmental changes may produce altered sex ratios that limit reproduction potential; therefore hatchling sex ratios should be monitored. Hatchlings are not externally sexually dimorphic, making sex identification difficult. This study established baseline plasma hormone concentrations in hatchling and post-hatchling green (Chelonia mydas) and loggerhead (Caretta caretta) sea turtles using High Performance Liquid Chromatography. Five hormones were assayed and were present in the majority of samples (testosterone: N.D.-10.12, progesterone: N.D.-0.43, estradiol: N.D.-4.78, estriol: N.D.-5.55 and estrone: N.D.-1.67 μg/mL). Plasma hormones did not distinguish hatchling sex because male and female ranges overlapped. Hormone concentrations varied with sex but also with incubation temperature, indicating that climate change could impact hatchling and posthatchling hormone profiles and thus could impact future fitness.
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Date Issued
2016
PURL
http://purl.flvc.org/fau/fd/FA00004626
Subject Headings
Sea turtles--Embryology., Sea turtles--Habitat--Conservation., Sex determination, Genetic., Loggerhead turtle--Effect of temperature on., Developmental genetics.
Format
Document (PDF)
Myofibril-Inducing RNA (MIR) is essential for tropomyosin expression and myofibrillogenesis in axolotl hearts
Title
Myofibril-Inducing RNA (MIR) is essential for tropomyosin expression and myofibrillogenesis in axolotl hearts.
Creator
Zhang, Chi, Jia, Pingping, Huang, Xupei, Sferrazza, Gian Franco, Athauda, Gagani, Achary, Mohan P., Wang, Jikui, Lemanski, Sharon L., Lemanski, Larry F.
Date Issued
2009-09-03
PURL
http://purl.flvc.org/fcla/dt/3327272
Subject Headings
Ambystoma mexicanum --embryology, Ambystoma mexicanum --genetics, Base Sequence, DNA, Complementary --genetics, Endoderm --physiology, Exons --genetics, Gene Expression Regulation, Developmental, Gene Knockdown Techniques, Genes, Recessive, Heart --embryology, Models, Genetic, Molecular Sequence Data, Muscle Proteins --biosynthesis, Muscle Proteins --genetics, Myocardial Contraction --physiology, Protein Isoforms, Reverse Transcriptase Polymerase Chain Reaction, Tropomyosin
Format
Document (PDF)
Rhetorical "Mosaicism" and Intractable Conflict: George W. Bush on Stem Cells
Title
Rhetorical "Mosaicism" and Intractable Conflict: George W. Bush on Stem Cells.
Creator
Brooten, Gary, Marin, Noemi, Florida Atlantic University
Abstract/Description
President Bush's 2001 speech on stem cell research showed unusual intermixing of rhetorical bits from past arguments of proponents and opponents, suggesting that such mixing is a distinct rhetorical strategy. Analyses revealed two communities that had engaged each other over reproductive biology issues for decades, developing distinct vocabularies and argumentative patterns in that interaction. The speech mixed fragments ofthese usages. Traditional textual analyses and analyses ofthe mixing...
Show morePresident Bush's 2001 speech on stem cell research showed unusual intermixing of rhetorical bits from past arguments of proponents and opponents, suggesting that such mixing is a distinct rhetorical strategy. Analyses revealed two communities that had engaged each other over reproductive biology issues for decades, developing distinct vocabularies and argumentative patterns in that interaction. The speech mixed fragments ofthese usages. Traditional textual analyses and analyses ofthe mixing itself showed that the mixing seems to reinforce traditional approaches to divided audiences by opening up many possibilities for the communities to draw different meanings from what is said. Analyses of responses to the speech showed such split understandings, and followup analyses to 2007 suggest that the speech helped freeze the character of the debate in the form Bush gave it. Mixing is a viable rhetorical strategy to help manage intractable issues with deeply divided audiences.
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Date Issued
2007
PURL
http://purl.flvc.org/fau/fd/FA00000902
Subject Headings
Bush, George W.--(George Walker),--1946---Political and social views., Medical genetics--Research--Moral and ethical aspects., Stem cells--Research--Moral and ethical aspects., Rhetorical criticism., Mosaicism., Developmental genetics--Moral and ethical aspects.
Format
Document (PDF)