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Molecular regulation of growth and molting in decapod crustaceans

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dc.contributor.authorMudron, Megan Reese, author
dc.contributor.authorMykles, Donald L., advisor
dc.contributor.authorGarrity, Deborah M., committee member
dc.contributor.authorCurthoys, Norman P., committee member
dc.date.accessioned2007-01-03T06:39:51Z
dc.date.available2007-01-03T06:39:51Z
dc.date.issued2014
dc.description.abstractThe green shore crab, Carcinus maenas, is a highly invasive species that inhabits coastal temperate zones worldwide. The reaction of C. maenas to acute temperature change was determined in six tissues (heart, gill, thoracic ganglion, eyestalk ganglion, Y-organ, and claw muscle) using genetic markers for temperature-induced metabolic stress, including HSP70, AMPKγ, mTOR, and Rheb. Animals were exposed to temperatures between 5° and 30°C for 1 or 2 h. mRNA levels in six tissues were quantified by quantitative RT-PCR (qPCR). The results indicate that C. maenas tolerated a wide temperature range, requiring 2-h exposures at 5 °C and 30 °C to affect tissue-specific changes in gene expression. Cm-HSP70 expression was robustly increased at 30 °C in all tissues. Ecdysteroids produced from the molting gland (Y-organ or YO) induce molting in decapod crustaceans. Reduction in molt-inhibiting hormone (MIH) activates the YO and animals enter premolt. At mid-premolt, YOs transition to the committed state, during which ecdysteroid production increases further. In blackback land crab (Gecarcinus lateralis), a tropical decapod species, SB1431542, an inhibitor of Activin receptors, decreases hemolymph ecdysteroid titers in premolt animals, suggesting that an Activin-like transforming-growth factor (TGF-β) is produced by the activated YO and drives the transition of the YO to the committed state. Myostatin (Gl-Mstn) is an Activin-like factor that is highly expressed in skeletal muscle. Rapamycin lowers hemolymph ecdysteroid titers by inhibiting mTOR, which controls global translation of mRNA into protein. Endpoint RT-PCR established that Gl-Mstn was expressed in the YO, not just muscle tissue. YOs were harvested from intact (intermolt) animals and from animals at 1, 3, 5, 7, and 14 days post-ESA. Quantitative PCR was used to quantify the effects of molt induction by eyestalk ablation (ESA) on gene expression. Expression of mTOR components peaked at 3 days post-ESA, which is consistent with the increased activity required for activation of the YO. Gl-Mstn expression also peaked at 3 days post-ESA, which is before the transition to the committed state at 7 days post-ESA. These results indicate that mTOR components are involved in activation of the YO, and Mstn is involved in transitioning the YO to the committed state.
dc.format.mediumborn digital
dc.format.mediummasters theses
dc.identifierMudron_colostate_0053N_12583.pdf
dc.identifier.urihttp://hdl.handle.net/10217/84008
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado State University. Libraries
dc.relation.ispartof2000-2019
dc.rightsCopyright and other restrictions may apply. User is responsible for compliance with all applicable laws. For information about copyright law, please see https://libguides.colostate.edu/copyright.
dc.subjectAMPK
dc.subjectcrustacean
dc.subjectHSP70
dc.subjectmolting
dc.subjectmTOR
dc.subjectmyostatin
dc.titleMolecular regulation of growth and molting in decapod crustaceans
dc.typeText
dcterms.rights.dplaThis Item is protected by copyright and/or related rights (https://rightsstatements.org/vocab/InC/1.0/). You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).
thesis.degree.disciplineBiology
thesis.degree.grantorColorado State University
thesis.degree.levelMasters
thesis.degree.nameMaster of Science (M.S.)

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