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- Title
- NOTOPLEURAL MUTATIONS ENHANCE DEFECTS IN IMAGINAL DISC EPITHELIAL MORPHOGENESIS AND MACROCHETE ELONGATION ASSOCIATED WITH MUTATIONS IN THE STUBBLE-STUBBLOID LOCUS.
- Creator
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Ruggiero, Robert, von Kalm, Laurence, University of Central Florida
- Abstract / Description
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The Stubble-stubbloid locus encodes a transmembrane serine protease (Stubble) necessary for the proper formation of sensory bristles, and the morphogenesis of leg and wing epithelia. Genetic and cell biological analysis indicate a role for Stubble in actin cytoskeletal dynamics and cell shape changes in developing epithelia and bristles. Previously reported genetic interactions between Stubble and the Rho1 signaling pathway suggest Stubble influences actin cytoskeleton dynamics in developing...
Show moreThe Stubble-stubbloid locus encodes a transmembrane serine protease (Stubble) necessary for the proper formation of sensory bristles, and the morphogenesis of leg and wing epithelia. Genetic and cell biological analysis indicate a role for Stubble in actin cytoskeletal dynamics and cell shape changes in developing epithelia and bristles. Previously reported genetic interactions between Stubble and the Rho1 signaling pathway suggest Stubble influences actin cytoskeleton dynamics in developing imaginal discs through interactions with the Rho1 pathway. This work will discuss a genetic screen conducted to further investigate the role of Stubble in bristle and imaginal disc morphogenesis. From 50,000 EMS-mutagenized chromosomes 12 enhancers of the recessive sbd201 allele were identified, including 6 new sbd alleles. Consistent with the current understanding of genetic interactions regulating imaginal disc morphogenesis, mutations in two Rho1 pathway genes, zipper (2 alleles) and Rho1, were isolated. Additionally, three new mutant enhancers of sbd201 were isolated, one of which has been identified as an allele of the cadherin gene Dacshous, another as an allele of the muscle myosin heavy chain gene, and the last as an allele of Notopleural (Np). Dominant and recessive mutations in the Stubble locus interact with the Np allele identified in this screen, in regards to both limb and bristle development, respectively. Mutations in the Np locus were first identified in 1936, but this locus remains poorly characterized and has never been cloned The genetic and phenotypic characterization of Np will be discussed along with experiments that have mapped the position of the Np locus to a 50kb region at the border of the 44F12, 45A1 cytological regions.
Show less - Date Issued
- 2006
- Identifier
- CFE0001347, ucf:46986
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001347
- Title
- STRUCTURE-FUNCTION ANALYSIS OF THE DROSOPHILA STUBBLE TYPE II TRANSMEMBRANE SERINE PROTEASE.
- Creator
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Morgan, Rachel, von Kalm, Laurence, University of Central Florida
- Abstract / Description
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Hormonally-triggered regulatory hierarchies play a major role in organismal development. Disruption of a single member of such a hierarchy can lead to irregular development and disease. Therefore, knowledge of the members involved and the mechanisms controlling signaling through such pathways is of great importance in understanding how resulting developmental defects occur. Type II transmembrane serine proteases (TTSPs) make up a family of cell surface-associated proteases that play important...
Show moreHormonally-triggered regulatory hierarchies play a major role in organismal development. Disruption of a single member of such a hierarchy can lead to irregular development and disease. Therefore, knowledge of the members involved and the mechanisms controlling signaling through such pathways is of great importance in understanding how resulting developmental defects occur. Type II transmembrane serine proteases (TTSPs) make up a family of cell surface-associated proteases that play important roles in the development and homeostasis of a number of mammalian tissues. Aberrant expression of TTSPs is linked to several human disorders, including deafness, heart and respiratory disease and cancer. However, the mechanism by which these proteases function remains unknown. The ecdysone-responsive Stubble TTSP of Drosophila serves as a good model in which to study the functional mechanism of the TTSP family. The Stubble protease interacts with the intracellular Rho1 (RhoA) pathway to control epithelial development in imaginal discs. The Rho1 signaling pathway regulates cellular behavior via control of gene expression and actin cytoskeletal dynamics. However, the mechanism by which the Stubble protease interacts with the Rho1 pathway to control epithelial development, in particular leg imaginal disc morphogenesis, has yet to be elucidated. The Stubble protein consists of several conserved domains. One approach to a better understanding of the mechanism of action of Stubble in regulating Rho1 signaling is to define which of the conserved domains within the protease are required for proper function. Sequence analysis of twelve recessive Stubble mutant alleles has revealed that the proteolytic domain is essential for proper function. Alleles containing mutations which disrupt regions of the protease domain necessary for protease activation or substrate binding, as well as those with deletions or truncations that remove some portion of the proteolytic domain, result in defective epithelial development in vivo. In contrast, mutations in other regions of the Stubble protein, including the disulfide-knotted and cytoplasmic domains, were not observed. Another important step for defining the connection between Stubble and Rho1 signaling is to identify a Stubble target that acts as an upstream regulator of the Rho1 pathway. We performed a genetic screen in which 97 of the 147 Drosophila non-olfactory and non-gustatory G-protein-coupled receptors (GPCRs), a family of proteins that has been shown to be protease-activated and to activate Rho1 signaling, were tested for interactions with a mutant allele of Stubble. We found 4 genomic regions uncovering a total of 7 GPCRs that interact genetically when in heterozygous combination with a Stubble mutant. Further analysis of these genes is necessary to determine if any of these GPCRs is targeted by Stubble during activation of the Rho1 pathway.
Show less - Date Issued
- 2008
- Identifier
- CFE0002285, ucf:47875
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002285
- Title
- GENETIC ANALYSIS OF RHOA SIGNALING DURING EPITHELIAL MORPHOGENESIS IN DROSOPHILA.
- Creator
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Leppert, Amanda Fitch, von Kalm, Laurence, University of Central Florida
- Abstract / Description
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Epithelial morphogenesis is contingent upon cell shape changes. Cell shape changes are the driving force for the metamorphosis of the adult Drosophila leg from the leg imaginal disc precursor. Genetic analysis has identified several Drosophila genes involved in regulating cell shape changes during leg disc morphogenesis. These include members of the RhoA signaling pathway and the product of the Stubble-stubbloid (Sb-sbd) locus, a transmembrane serine protease. Mutations in the Sb-sbd gene...
Show moreEpithelial morphogenesis is contingent upon cell shape changes. Cell shape changes are the driving force for the metamorphosis of the adult Drosophila leg from the leg imaginal disc precursor. Genetic analysis has identified several Drosophila genes involved in regulating cell shape changes during leg disc morphogenesis. These include members of the RhoA signaling pathway and the product of the Stubble-stubbloid (Sb-sbd) locus, a transmembrane serine protease. Mutations in the Sb-sbd gene interact genetically with the members of the RhoA signaling pathway, however the nature of the relationship between Sb-sbd serine protease activity and RhoA signaling is not understood.To identify additional components of the RhoA signaling pathway that may help us to understand the role of the Sb-sbd protease in RhoA signaling the Drosophila genome was systematically scanned for genes that interact with Sb-sbd and RhoA mutations using deletions/deficiencies of specified regions of each chromosome. A total of 201 deficiencies uncovering approximately 84.9-91% of the euchromatic genome and spanning the X, second, and third chromosoms were tested. Of the 201 deficiencies tested, five putative interacting genetic regions and one gene within these deficiencies were identified. The candidate gene Eip78C encodes a nuclear steroid hormone receptor previously identified as having an important role in metamorphosis.
Show less - Date Issued
- 2004
- Identifier
- CFE0000046, ucf:46104
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000046
- Title
- MAPPING AND CHARACTERIZATION OF 18-5 AND 12-5, GENES WHICH POTENTIALLY LINK THE RHOA SIGNALING PATHWAY TO THE ECDYSONE RESPONSE IN DROSOPHILA EPITHELIAL MORPHOGENESIS.
- Creator
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Fox, Samuel, von Kalm, Laurence, University of Central Florida
- Abstract / Description
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Systemic steroid hormone and intracellular signaling pathways are known to act cooperatively during the development of vertebrate and invertebrate epithelia. However, the mechanism of this interaction is poorly understood. Morphogenesis of Drosophila leg imaginal disc epithelia is regulated both by the steroid hormone 20-hydroxyecdysone (ecdysone) and the RhoA GTPase signaling pathway. Recent evidence suggests that these pathways act cooperatively to control imaginal disc morphogenesis. Thus,...
Show moreSystemic steroid hormone and intracellular signaling pathways are known to act cooperatively during the development of vertebrate and invertebrate epithelia. However, the mechanism of this interaction is poorly understood. Morphogenesis of Drosophila leg imaginal disc epithelia is regulated both by the steroid hormone 20-hydroxyecdysone (ecdysone) and the RhoA GTPase signaling pathway. Recent evidence suggests that these pathways act cooperatively to control imaginal disc morphogenesis. Thus, leg imaginal disc morphogenesis is an excellent system in which to study the interaction of steroid hormone and intracellular signaling pathways. We have identified mutations in three genes, 12-5, 18-5, and 31-6, with roles in the morphogenesis of leg epithelia. Of particular interest, these mutations interact genetically with each other, mutations in the RhoA signaling pathway, and the ecdysone regulated Sb-sbd (Stubble) transmembrane serine protease. This suggests that the 12-5, 18-5, and 31-6 gene products may link hormone and RhoA signaling responses. The goal of this research was to identify and characterize the 18-5 and 12-5 genes in order to discern the mechanistic relationship between the RhoA pathway and ecdysone hierarchy.18-5 and 12-5 were precisely mapped to molecular locations within the Drosophila genome utilizing a P-element recombination mapping technique. This work narrowed the location of the 18-5 locus to within an interval of 112 kb within the Drosophila genome sequence. This interval contains 17 known and predicted genes. I also mapped the location of the 12-5 locus to a 2.6 Mb interval of the 2nd chromosome. Based on phenotypic analyses and the site of the molecularly mapped interval, a candidate gene for the 18-5 mutation was identified. Sequence analysis of the candidate gene was inconclusive and requires further analysis. Genetic interaction assays indicate that the 18-5 gene product acts upstream or at the level of Rho kinase in the RhoA signaling pathway.
Show less - Date Issued
- 2006
- Identifier
- CFE0001290, ucf:46882
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001290
- Title
- PREVENTING CHILDHOOD OBESITY IN SCHOOL-AGED CHILDREN: RELATIONSHIPS BETWEEN READING NUTRITION LABELS AND HEALTHY DIETARY BEHAVIORS.
- Creator
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Bogers, Kimberly S, Quelly, Susan, University of Central Florida
- Abstract / Description
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Childhood obesity is a prevalent problem in the United States. Obesity increases the risk for many diseases. Obese children are likely to become obese adults with additional comorbidities. Studies have reported mixed findings regarding associations between reading nutrition labels and improved dietary behaviors/healthy weight status. The purpose of this study is to determine whether the frequency of children reading nutrition labels is related to frequency of performing 12 dietary behaviors....
Show moreChildhood obesity is a prevalent problem in the United States. Obesity increases the risk for many diseases. Obese children are likely to become obese adults with additional comorbidities. Studies have reported mixed findings regarding associations between reading nutrition labels and improved dietary behaviors/healthy weight status. The purpose of this study is to determine whether the frequency of children reading nutrition labels is related to frequency of performing 12 dietary behaviors. De-identified baseline data from a previous quasiexperimental pilot study were analyzed. Data were collected from 4th and 5th graders (n = 42) at an after-school program. An adapted paper survey was administered to the children to measure the number of days (0�7) they read nutrition labels and performed 12 dietary behaviors over the preceding week. Due to non-normal distribution of data, non-parametric Spearman rho correlations were conducted to determine relationships between frequency of reading nutrition labels and dietary behaviors. Positive correlations were found between frequency of reading nutrition labels and eating fruit for breakfast; eating vegetables at lunch/dinner; eating whole grain/multigrain bread (p less than .05); eating fruit for a snack; eating vegetables for a snack (p less than .01). Frequency of reading nutrition labels was inversely related to drinking soda/sugar-sweetened beverages (p less than .05). Significant relationships were found between frequency of reading nutrition labels and several dietary behaviors associated with childhood obesity prevention. Findings are promising and support the need for further intervention research to determine potential direct influences of children reading nutrition labels on dietary behaviors.
Show less - Date Issued
- 2018
- Identifier
- CFH2000281, ucf:45722
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000281
