Havinga, M.A.D. (2016) Effects of microbial pressure on maternal investment of immune defense in Zebra Finch eggs (Taeniopygia guttata). Research Project 1 (minor thesis), Ecology and Evolution.
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Abstract
Microbial communities in different ecosystems are very diverse. To be able to survive in changing and variable environments, animals should match their behavior and their physiology with the environment they are in. To maintain the highest possible fitness, animals should match their behavior and their physiology with the environment they are in. The immune system of an animal is the first line of defense. In different environments, different defense mechanisms are necessary. Birds are ideal model system to study physiological adaptations because in birds it is clear that the eggs are the main output of reproduction. I expected that an animals should have a flexible immune system and thereby a shift in physiology. It is not yet known if and how adult females birds change their physiology upon changes in environmental microbial pressure, and whether they adjust the maternal deposition of immune defense proteins in their eggs. One of the potential mechanisms to limit or reduce microbial infections is the deposition of antimicrobial substances and antibodies (lipophilic components, lysozyme, ovotransferrin, maternal antibodies) in the albumen and in the egg yolk of newly laid eggs to prevent bacteria from impeding embryonic development. I experimentally tested whether artificially change of external microbial community composition affects antimicrobial protein deposition in Zebra Finch (Taeniopygia guttata) eggs. Birds were kept in two different treatments, one sterilized soil bedding treatment and a control group with regular microbial communities in the provided soil. I measured lysozyme and ovotransferrin activity in egg albumen as well as haptoglobin concentration and lysis and agglutination capacity of maternal plasma. I found no significantly different treatment effects on measures of immune function. However, there is an effect of time in ovotransferrin activity, which declines with laying sequence, suggesting constrained ovotransferrin availability. Also the lysozyme concentration increased during different clutches. A significant increase is found from the first to the third clutch. The question remains if a lower concentration of a defense protein means that you are that healthy that you don’t need the protein, or that you are that ill that you are not able to form this protein.
Item Type: | Thesis (Research Project 1 (minor thesis)) |
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Degree programme: | Ecology and Evolution |
Thesis type: | Research Project 1 (minor thesis) |
Language: | English |
Date Deposited: | 15 Feb 2018 08:11 |
Last Modified: | 15 Feb 2018 08:11 |
URI: | https://fse.studenttheses.ub.rug.nl/id/eprint/13774 |
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