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spelling ndltd-OhioLink-oai-etd.ohiolink.edu-bgsu13001204512021-08-03T05:29:32Z Regulation of Ecdysone 20-Monooxygenase Activity in the Tobacco Hornworm, Manduca sexta and the Apparent Occurrence of this Activity in Ascaris suum (Nematoda) Drummond, Christopher Anson Agriculture Animals Animal Sciences Biochemistry Biology Cellular Biology Developmental Biology Endocrinology Entomology Organismal Biology Parasitology Physiology Ecdysone 20-monooxygenase Manduca sexta second messengers cyclic guanosine monophosphate ecdysteroidogenesis steroids ecdysone 20-hydroxyecdysone endocrinology At specific intervals, increased concentrations of two steroid hormones, i.e., ecdysone (E) and 20-hydroxyecdysone (20E), elicit developmental changes in arthropods. Conversion of E to the active molting hormone, 20E, in the tobacco hornworm Manduca sexta is catalyzed by the cytochrome P450-containing ecdysone 20-monooxygenase system (E20M). During embryogenesis, M. sexta E20M activity increased for the first 72 hours at which time it peaked and subsequently significantly declined. The increased activity coincided with the increase of free ecdysteroids and the progression of two embryonic molts. In midgut tissue of fifth instar M. sexta, decreases in second messenger 3’,5’cyclic guanosine monophosphate (cGMP) concentration inhibited day five E20M activity, but increases in cGMP concentration restored E20M activity. Midgut cGMP content peaked on day five of the instar in concert with the highest level of E20M activity observed. Molecular studies with midgut tissue demonstrated that the E agonist RH-5849 elicited increases in E20M (the shade gene) expression. In the presence of two guanylate cyclase inhibitors, E20M expression significantly increased. Inhibition remediation by pharmacological means resulted in significantly decreased shade expression. While it is unclear as to where cGMP exerts its effects on E20M activity, the data indicated that the second messenger affected the level of transcription, translation, or enzyme activity either individually or in some combination. Interestingly, E20M activity also was found to be affected by six synthesized anthraquinones suggesting that these compounds can serve to disrupt M. sexta development. Lastly, E20M-like activity was observed in female Ascaris suum (Nematoda) both in muscle and reproductive tissue. Although E20M localization in muscle was unclear, in reproductive tissue E20M activity resided mainly with microsomes. This work provides a number of important insights into the regulation of M. sexta E20M during development, a role of cGMP in these events, and the possible occurrence of E20M in the parasitic nematode Ascaris suum. 2011-03-14 English text Bowling Green State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1300120451 http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1300120451 unrestricted This thesis or dissertation is protected by copyright: all rights reserved. It may not be copied or redistributed beyond the terms of applicable copyright laws.
collection NDLTD
language English
sources NDLTD
topic Agriculture
Animals
Animal Sciences
Biochemistry
Biology
Cellular Biology
Developmental Biology
Endocrinology
Entomology
Organismal Biology
Parasitology
Physiology
Ecdysone 20-monooxygenase
Manduca sexta
second messengers
cyclic guanosine monophosphate
ecdysteroidogenesis
steroids
ecdysone
20-hydroxyecdysone
endocrinology
spellingShingle Agriculture
Animals
Animal Sciences
Biochemistry
Biology
Cellular Biology
Developmental Biology
Endocrinology
Entomology
Organismal Biology
Parasitology
Physiology
Ecdysone 20-monooxygenase
Manduca sexta
second messengers
cyclic guanosine monophosphate
ecdysteroidogenesis
steroids
ecdysone
20-hydroxyecdysone
endocrinology
Drummond, Christopher Anson
Regulation of Ecdysone 20-Monooxygenase Activity in the Tobacco Hornworm, Manduca sexta and the Apparent Occurrence of this Activity in Ascaris suum (Nematoda)
author Drummond, Christopher Anson
author_facet Drummond, Christopher Anson
author_sort Drummond, Christopher Anson
title Regulation of Ecdysone 20-Monooxygenase Activity in the Tobacco Hornworm, Manduca sexta and the Apparent Occurrence of this Activity in Ascaris suum (Nematoda)
title_short Regulation of Ecdysone 20-Monooxygenase Activity in the Tobacco Hornworm, Manduca sexta and the Apparent Occurrence of this Activity in Ascaris suum (Nematoda)
title_full Regulation of Ecdysone 20-Monooxygenase Activity in the Tobacco Hornworm, Manduca sexta and the Apparent Occurrence of this Activity in Ascaris suum (Nematoda)
title_fullStr Regulation of Ecdysone 20-Monooxygenase Activity in the Tobacco Hornworm, Manduca sexta and the Apparent Occurrence of this Activity in Ascaris suum (Nematoda)
title_full_unstemmed Regulation of Ecdysone 20-Monooxygenase Activity in the Tobacco Hornworm, Manduca sexta and the Apparent Occurrence of this Activity in Ascaris suum (Nematoda)
title_sort regulation of ecdysone 20-monooxygenase activity in the tobacco hornworm, manduca sexta and the apparent occurrence of this activity in ascaris suum (nematoda)
publisher Bowling Green State University / OhioLINK
publishDate 2011
url http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1300120451
work_keys_str_mv AT drummondchristopheranson regulationofecdysone20monooxygenaseactivityinthetobaccohornwormmanducasextaandtheapparentoccurrenceofthisactivityinascarissuumnematoda
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