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dc.rights.licenseRestricted to current Rensselaer faculty, staff and students. Access inquiries may be directed to the Rensselaer Libraries.
dc.contributorSwank, Douglas M.
dc.contributorCorr, David T.
dc.contributorChan, Deva
dc.contributorKirkton, Scott
dc.contributor.authorLoya, Amy K.
dc.date.accessioned2021-11-03T09:24:28Z
dc.date.available2021-11-03T09:24:28Z
dc.date.created2021-07-07T16:14:08Z
dc.date.issued2020-12
dc.identifier.urihttps://hdl.handle.net/20.500.13015/2667
dc.descriptionDecember 2020
dc.descriptionSchool of Engineering
dc.description.abstractThe TnC isoform expressed in minimally SA vertebrate skeletal muscle has one less calcium binding site than that of the moderately SA vertebrate cardiac muscle. This relationship mimics that of the TnC isoforms expressed in Drosophila IFM and jump muscle. Thus, we are interested in studying SA and SD, because defects in both of these properties have been linked to heart diseases such as dilated and hypertrophic cardiomyopathies. Our goal is to increase our understanding of SA and SD to contribute to the development of treatments for various heart diseases.
dc.description.abstractGenerating high, sustained power from a muscle undergoing a cyclical lengthening and shortening contraction pattern requires fast yet efficient activation and relaxation rates. To enhance activation and force levels during contraction, some muscle types have evolved stretch activation (SA), a delayed increase in force following rapid muscle lengthening. While SA has been investigated for decades, its complementary phenomenon, shortening deactivation (SD), a delayed decrease in force following muscle shortening, has not been directly measured. Together, these properties play an important role in increasing power production and efficiency in cyclically contracting muscles, namely Drosophila indirect flight muscles (IFM), Lethocerus IFM, and vertebrate hearts. In the first study of this dissertation, to enable mechanistic investigations into SD and compare it to SA, we developed a protocol to elicit SA and SD in skinned muscle fibers from three muscles: the high SA Drosophila and Lethocerus IFM, and low SA Drosophila jump muscle. In the second study, we investigated an unusual troponin C (TnC) isoform (TnC4) found in IFM, which has only one calcium binding site and has been proposed to play a critical role in SA. We analyzed the effects of replacing the TnC isoform (TnC1) native to the Drosophila jump muscle with TnC4 in order to identify functional changes that could explain how a muscle with minimal SA capacity might acquire the characteristics of muscle types with high SA.
dc.language.isoENG
dc.publisherRensselaer Polytechnic Institute, Troy, NY
dc.relation.ispartofRensselaer Theses and Dissertations Online Collection
dc.subjectBiomedical engineering
dc.titleUnderstanding stretch activation and shortening deactivation in drosophila melanogaster
dc.typeElectronic thesis
dc.typeThesis
dc.digitool.pid180498
dc.digitool.pid180499
dc.digitool.pid180500
dc.rights.holderThis electronic version is a licensed copy owned by Rensselaer Polytechnic Institute, Troy, NY. Copyright of original work retained by author.
dc.description.degreePhD
dc.relation.departmentDept. of Biomedical Engineering


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