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Effects of 20-hydroxyecdysone and other hormones on egg development, and identification of a vitellin-binding protein in the ovary of the tick, Amblyomma hebraeum

dc.contributor.authorFriesen, Kevin
dc.contributor.authorKaufman, Reuben
dc.date.accessioned2016-05-06
dc.date.accessioned2022-05-28T00:38:18Z
dc.date.available2022-05-28T00:38:18Z
dc.date.issued2004
dc.description.abstractPartially fed adult female Amblyomma hebraeum ticks were injected with 20-hydroxyecdysone (20E; up to 43 μg/g body weight (bw)), juvenile hormone III (JH III; up to 100 μg/g bw), bovine insulin (up to 2000 mU/g bw), or triiodothyronine (up to 200 ng/g bw) in an attempt to stimulate vitellogenesis. Of these, only 20E stimulated synthesis and release of vitellogenin (Vg). Immunoblot analysis revealed that Vg-synthesis occurred in the fat body. However, consistent with earlier observations suggesting that a distinct signal may be required for Vg-uptake, there was no significant Vg-uptake by oocytes of partially fed, 20E-treated ticks. Because Vg-uptake commonly occurs via receptor-mediated endocytosis (i.e., a specific Vg-receptor), we attempted to identify a vitellin (Vt)-binding protein in ovaries of engorged female ticks. A single 86 kDa Vt-binding protein was identified, even under reducing conditions (2-mercaptoethanol), by a ligand-blotting technique. Sodium salt of suramin (5 mM) inhibited binding of Vt to the 86 kDa protein. However, this protein was also detected in ovaries from small partially fed ticks (50–100 mg), suggesting that the inability of 20E to stimulate Vg-uptake in partially fed ticks may not have been due to the absence of a Vg-receptor.
dc.description.urihttps://library.macewan.ca/cgi-bin/SFX/url.pl/8FM
dc.identifier.citationFriesen, K. J., & Kaufman, W. R. (2004). Effects of 20-hydroxyecdysone and other hormones on egg development, and identification of a vitellin-binding protein in the ovary of the tick, Amblyomma hebraeum. Journal of Insect Physiology, 50(6), 519-529. doi:10.1016/j.jinsphys.2004.03.008
dc.identifier.doihttps://doi.org/10.1016/j.jinsphys.2004.03.008
dc.identifier.urihttps://hdl.handle.net/20.500.14078/1015
dc.languageEnglish
dc.language.isoen
dc.rightsAll Rights Reserved
dc.subjectixodid ticks
dc.subjectamblyomma hebraeum
dc.subjectvitellogenesis
dc.subjectvitellogenin
dc.subjectvitellin
dc.subject20-hydroxyecdysone
dc.subjectjuvenile hormone
dc.subjectvitellogenin-receptor
dc.subjectinsulin
dc.subjecttriiodothyronine (T3)
dc.titleEffects of 20-hydroxyecdysone and other hormones on egg development, and identification of a vitellin-binding protein in the ovary of the tick, Amblyomma hebraeumen
dc.typeArticle

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