Conférences et séminaires » Séminaire présenté par U. Bauchlinger
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Tissue turnover and the extent of phenotypic flexibility in organ size of migrating birds
Par : Dr. Ulf BAUCHLINGER invité par F. Bertile
Date : Jeudi 27 octobre 2011 à 13h30
Lieu : Amphi Grünewald - Bâtiment 25
Size of tissues is subjected to phenotypic flexibility that adjusts organ size to changes in functional demands in response to environmental change. A new hypothesis suggests that the rate of tissue-specific degradation during fasting is related to the tissue-specific rate of protein turnover. This hypothesis predicts allometric scaling of tissue-specific protein turnover rate across species and so provides estimates of the rate of tissue degradation for a specific tissue in relation to other tissues within a given animal. Based on carbon isotopic incorporation rate that is used as proxy for protein turnover we can now predict, which tissues are the ones reduced the most (for example liver and small intestine) and which are the tissues to be reduced the least (bone and brain) and which tissues rank intermediate (kidney, gizzard, heart, skeletal muscles). Furthermore, the hypothesis that protein turnover determines the degree of tissue specific mass loss during fasting predicts that rate of change is independent of activity levels of tissues. The proposed hypothesis, the immediately derived predictions and its support from the limited data on vertebrate tissue turnover and phenotypic mass change will be discussed.