Dr. Laurie B. Cook’s Laboratory
Tameciah Browne (M.S. Student) writing end-of-project report
The expansion and development of adipose tissue involves a cellular transformation from pre-adipocyte to adipocyte that is accompanied by the transient evolution of a single primary cilium on the developing cell. To better understand the cellular signaling pathways regulated by those cilia, a method for isolating them is being developed in preparation for mass spectrometry analysis of ciliary protein fractions.
Bianca Camillaci (M.S. Student)
When differentiating adipocytes display a transient primary cilium, the melanin-concentrating hormone receptor translocates to it, presumably as a mechanism of regulating MCH signaling. This research focuses on the role of MCHR1 in primary cilia in regulating expression of Vitamin D Receptor expression in pre-adipocytes. Potentially this work links an appetite hormone to VitD-regulated metabolic activity in fat cells.
Katie Courtney (B.S. Student, Delta College)
The isolation of G protein-coupled receptors into cholesterol-rich caveolar membrane regions regulates their signaling. Receptors for the appetite hormone, MCH, are highly enriched in these caveolae in many cell types, however since the adipocyte switches from a caveolae-less to a caveolae-full cell during development, we hypothesize that MCH signaling is changed by the relocalization of its receptor in/out of caveolae membrane regions. This research aims to co-purify MCHR1 with caveolin-1 from pre- (control) and post- (experimental) adipocytes to verify receptor membrane localization to caveolae. Future experiments will examine MCH signaling changes at the two developmental stages.
Clarissa Steier (M.S. student)
Melanin-concentrating hormone causes cytoskeletal rearrangements resulting in rounding of pre-adipocytes in culture, which is an indication that this appetite hormone may contribute to the expansion and differentiation of adipose tissue. This research is an extension of previously published work from our lab, (Cook, Shum & Portwood, 2013), and will investigate the role MCH may play in controlling the signaling connections between the cytoskeleton and the expansion of adipose as a tissue.
Dayanara Torres (B.S. student)
We hypothesize that an appetite-stimulating hormone, MCH, initiates cellular changes in the adipocyte that facilitate the storage of lipid. The signaling pathways that control lipid metabolism in adipocytes often intersect with glucose metabolism. We have preliminary evidence to suggest that MCH facilitates the translocation of GLUT4 glucose transporters to the plasma membrane in response to insulin, as part of an energy storage process. This research will test this hypothesis via fluorescence-immunolocalization experiments and gene expression profiles connected to the Insulin-GLUT4 pathway.
Meghan Walters (B.S. Student, Honors College)
When differentiating adipocytes display a transient primary cilium, the melanin-concentrating hormone receptor translocates to it, presumably as a mechanism of regulating MCH signaling. The translocation of MCH to primary cilia alters the expression of genes that regulate the circadian clock of adipose tissue. Circadian rhythm genes are connected to energy expenditure, potentially linking MCH signaling to control of lipid storage in these cells.
Dr. Adam Rich’s Laboratory
Meghan Denny (M.S. Student) writing thesis
Anoctamin 1 codes for a calcium activated chloride selective ion channel that is involve in a variety of physiological functions ranging from saliva formation to pain receptor activity to gastrointestinal motility. Three ANO1 transcripts are identified in the latest zebrafish genome assembly but expression has not been confirmed. Meghan is now finishing her thesis, writing only. Last spring and this summer Meghan, Tara Sweet, and I tried to determine the 5 prime end of expressed Ano1 mRNA. Although sequence exists in the databases it has not been confirmed. It is also possible that unknown Ano1 variants, with different 5 prime ends, exist. We were unsuccessful.
Ian Shannon (M.S. Student) writing thesis
The overall goal for this thesis is to characterize ICC distribution within the zebrafish GI tract. In mice and humans there are several populations of ICC and distinct functions have been attributed to each population. Although the existence of zebrafish ICC has been documented by our laboratory, ICC distribution in adults and in developing zebrafish GI tracts has never been characterized.
Ryan Peters (M.S. Student)
Gastrointestinal smooth muscle spontaneously contracts in a rhythmic and coordinated manner to support mixing and propulsion of intestinal contents. Our laboratory using time lapse imaging to measure gastrointestinal motility, but these measurements do not provide information about contractile force. The goal for this thesis is to build a tension recording apparatus suitable for rings of zebrafish gastrointestinal smooth muscle. Tension will be recorded from gastrointestinal rings from wild type zebrafish, and after anoctamin 1 channel antagonists have been applied to determine the physiological role for anoctamin ion channels in gastrointestinal activity.
Ashley Wills (M.S. Student)
The anoctamin gene family consists of 10 members in humans and in zebrafish. Anoctamin 1 codes for a calcium activated ion channel and has been shown to regulate fluid secretion in salivary gland, pain sensation in afferent spinal neurons, insulin secretion by pancreatic beta cells, and in regulation of gastrointestinal smooth muscle activity by interstitial cells of Cajal. Anoctamin 2 also codes for a calcium activated ion channel but much less is known about it’s expression and physiological functions. The goal for this thesis is to determine the expression pattern for anoctamin 2 in zebrafish.
Bailey Majtyka (M.S. Student)
Anoctamin 1 is a calcium activated chloride channel that is essential for development of spontaneous coordinated motility patterns in the mouse jejunum. Anoctamin 1 is expressed on interstitial cells of Cajal. It is well known that a rise in intracellular calcium within interstitial cells precedes muscular contractions. An association between the rise in interstitial cell calcium and spontaneous contractions is assumed, but has not been demonstrated. This thesis will utilize a transgenic zebrafish expressing GCaMP, a calcium indicator, to determine the relationship between calcium and anoctamin 1 channel function.
Claire Makowski (B.S. Student, Biology Honors) writing thesis
Published experiments by Amazzone et al showed that diabetic patients with delayed gastric emptying express a novel anoctamin 1 splice variant compared to diabetic patients with normal gastrointestinal transit times. Using the zebrafish we will examine anoctamin 1 expression in gastrointestinal tissue to determine if a similar splice variant is expressed. If we do find altered expression then experiments will be designed to determine if delayed gastric emptying results from expression of the altered splice variant, or if expression of the slice variant is induced in response to delayed gastric emptying.
Brian Smith (B.S. Student)
Measurement of gastrointestinal motility in zebrafish larvae is accomplished using time lapse imaging and subsequent spatiotemporal analysis. Zebrafish remain transparent during development and imaging is performed after larvae are anesthetized, immobilized, and positioned laterally. Inflation of the swim bladder occurs approximately 5 days after fertilization and enables fish to maintain neutral buoyancy. Swim bladder inflation also contributes to a dorsal-side up orientation, creating a problem for imaging studies. This project will attempt to develop a protocol to prevent swim bladder inflation, or to deflate the swim bladder to improve long term imaging experiments.
Tyler Laird (B.S. Student - first semester)
Learn zebrafish husbandry and the role for interstitials cells of Cajal in regulation of gastrointestinal motility.
Sara Llopas (B.S. Student - first semester)
Learn zebrafish husbandry and the role for interstitials cells of Cajal in regulation of gastrointestinal motility. Learn imaging and analysis methods to measure gastrointestinal motility patterns in developing zebrafish.
Aryona Valastro (B.S. Student - first semester)
Learn zebrafish husbandry and the role for interstitials cells of Cajal in regulation of gastrointestinal motility. Begin to learn immunohistochemistry and fluorescence imaging techniques.
Nisa Vyverburg (B.S. Student - first semester)
Learn zebrafish husbandry and the role for interstitials cells of Cajal in regulation of gastrointestinal motility. Begin to learn immunohistochemistry and fluorescence imaging techniques.
Dr. Rey Sia’s Laboratory
Imran Tahir (M.S. Student) & Andrew Connolly (B.S. Student)
The major mitochondrial nuclease, Nuc1p, the 5’ flap endonuclease, Rad27p, and Ku70p, required for non-homologous end joining, are believed to be key regulators of mitochondrial DNA repair mechanisms in the budding yeast, Saccharomyces cerevisiae. The research is focused on identifying the role of these proteins in mitochondrial DNA repair mechanisms involving both spontaneous and induced direct repeat recombination events.
Brooke Scott (B.S. student) & Joshua Dailey (B.S. student)
The Ku70p-Ku80p complex required for the non-homologous end joining (NHEJ) repair pathway in the nucleus. NHEJ is the major double-strand break repair pathway in higher eukaryotes. The research focuses on determining whether loss of this complex leads to impaired respiration and altered spontaneous direct repeat recombination events in the mitochondria of the budding yeast, Saccharomyces cerevisiae.