Corticosterone Promotes Development of Cannibalistic Morphology and Inhibits Tissue Regeneration in Axolotls (Ambystoma mexicanum )
tarafından
 
MacFarlane, Shawn, author.

Başlık
Corticosterone Promotes Development of Cannibalistic Morphology and Inhibits Tissue Regeneration in Axolotls (Ambystoma mexicanum )

Yazar
MacFarlane, Shawn, author.

ISBN
9780438180369

Yazar Ek Girişi
MacFarlane, Shawn, author.

Fiziksel Tanımlama
1 electronic resource (52 pages)

Genel Not
Source: Masters Abstracts International, Volume: 57-06M(E).
 
Advisors: Leslie R. Kerr; Dennis L. Murray Committee members: Carolyn M. Kapron.

Özet
Salamanders are capable of tissue regeneration throughout all life-stages, which requires the dedifferentiation of mature cells to regrow lost tissues. Dedifferentiation is promoted by degradation of the extracellular matrix by matrix metalloproteases, as well as lysosomal degradation of intracellular and cell-surface proteins that mark cells as part of a mature lineage. Salamanders are also capable of developing cannibalistic phenotypes, plastic traits that are elicited by environmental stressors that result in elevated circulating glucocorticoid (e.g., corticosterone) levels that underlie many fundamental adaptive changes in morphology. Interestingly, the direct effect of corticosterone on regeneration and the cannibalistic phenotype have yet to be examined. In the present thesis, axolotls (Ambystoma mexicanum) were exposed to exogenous corticosterone and 50% of the distal tail tissue was removed. The effects of high corticosterone levels on matrix metalloprotease (MMP-2, MMP-9) and lysosomal acid phosphatase (LAP) activity were assessed; these are two classes of enzymes which are markers of extracellular matrix and intracellular remodeling during regeneration, respectively. We found that elevated corticosterone levels inhibited tissue regeneration, by prolonging the dedifferentiation phase as indicated by increased LAP and reduced MMP-2 and MMP-9 activity. Elevated corticosterone levels also promoted the cannibalistic morphology and this effect was strongest among smaller individuals.

Notlar
School code: 0513

Konu Başlığı
Physiology.

Tüzel Kişi Ek Girişi
Trent University (Canada). Environmental and Life Sciences.

Elektronik Erişim
http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqm&rft_dat=xri:pqdiss:10830004


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