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Noninvasive measurement of steroid homones and effect of hormonal manipulation on behaviour in the gecko Paroedura picta
Matušková, Lucie ; Kratochvíl, Lukáš (advisor) ; Fraňková, Marcela (referee)
Hormones influence life of all animals. Not only they affect physiological changes in organisms, but also impact their behaviour. This work focuses at two main groups of steroid hormones: glucocorticoids and androgens. Glucocortiods are activated in response to stress. Their levels can be measured using non-invasive methods, which have a range of advantages. The main advantage is the feedback-free sample collection for enzyme immunoassay. As the measurement involves metabolites of the hormones rather than the hormones themselves, prior validation of the method is, however, necessary. This work reports on a study aiming to validate non-invasive measurement on the Madagascar Ground Gecko (Paroedura Picta). The validation was based on ACTH challenge test: Synacthen Depot was injected, which should lead to increased blood level of glucocorticoids. The validation, however, was not successful. The measurement did not discover significant increase in the levels of the metabolites of glucocorticoids. In addition, the work focuses on behavioural effects of testosterone, the primary androgen. Hormonal manipulations have been carried out on several male and female specimens. The results have discovered differences in sexual behaviour between control groups. On the other hand, the hormonal manipulations had no...
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Hormonal control of male traits in leopard gecko, Eublepharis macularius
Schořálková, Tereza ; Kratochvíl, Lukáš (advisor) ; Rehák, Ivan (referee)
It is generally believed that the presence of male traits is regulated by androgens. This thesis is designed to reveal the influence of testosterone on male traits in the leopard gecko, Eublepharis macularius. The noninvasive skin application mixture of vegetable oil and testosterone was used to manipulate the hormonal status of females and castrated males. This method has proven to be an effective alternative to the widely used hormonal implants. Manipulation was successfully validated, and there was apparent progressive increase of male sexual behavior in both groups. In females, the onset lasted much longer time, but both groups were able to perform all components of males sexual behaviour. Furthermore, I found that, contrary to widespread view, male sexual behavior persisted several weeks after reduction of testosterone levels in both manipulated groups. These results bring new evidence for temporary organization of male sexual behaviour by testosterone. Powered by TCPDF (www.tcpdf.org)
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Role of steroid hormones in control of sexually dimorphic traits in eyelid geckos (Eublepharidae)
Tóthová, Lucia ; Kratochvíl, Lukáš (advisor) ; Landová, Eva (referee)
The importance of sex hormones in formation, development and regulation of sexually dimorphic behavior does not need to be stressed. However, their actual organizational and activational effects and interactions in sexual differentiation and determination are not fully understood yet. The aim of our study was to explore the effects of hormonal manipulation in eyelid-geckos (family Eublepharidae) and enlighten the role of steroid hormones in formation of sexual differences. In the first part of our work we tried to reverse sex of Yucatán banded gecko (Coleonyx elegans) by hormonal manipulation in the early embryogenesis. This species has genotypic sex determination with chromosome set X1X2Y. In reverted individuals we aimed to examine the effects of steroid hormones on sexually dimorphic traits and in case of full sexual reversion and fertility of progeny, we would search for the sex-determining gene. In the second part, we studied masculinization effects of testosterone in females of leopard gecko (Eublepharis macularius). In contrast with the Coleonyx elegans mentioned above, this species has temperature dependent sex determination, even though these two species are closely related. Experimental females were implanted with testosterone implants and therefore their testosterone levels were increased in...
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Hormonal control of male traits in leopard gecko, Eublepharis macularius
Schořálková, Tereza ; Kratochvíl, Lukáš (advisor) ; Rehák, Ivan (referee)
It is generally believed that the presence of male traits is regulated by androgens. This thesis is designed to reveal the influence of testosterone on male traits in the leopard gecko, Eublepharis macularius. The noninvasive skin application mixture of vegetable oil and testosterone was used to manipulate the hormonal status of females and castrated males. This method has proven to be an effective alternative to the widely used hormonal implants. Manipulation was successfully validated, and there was apparent progressive increase of male sexual behavior in both groups. In females, the onset lasted much longer time, but both groups were able to perform all components of males sexual behaviour. Furthermore, I found that, contrary to widespread view, male sexual behavior persisted several weeks after reduction of testosterone levels in both manipulated groups. These results bring new evidence for temporary organization of male sexual behaviour by testosterone. Powered by TCPDF (www.tcpdf.org)
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Noninvasive measurement of steroid homones and effect of hormonal manipulation on behaviour in the gecko Paroedura picta
Matušková, Lucie ; Kratochvíl, Lukáš (advisor) ; Fraňková, Marcela (referee)
Hormones influence life of all animals. Not only they affect physiological changes in organisms, but also impact their behaviour. This work focuses at two main groups of steroid hormones: glucocorticoids and androgens. Glucocortiods are activated in response to stress. Their levels can be measured using non-invasive methods, which have a range of advantages. The main advantage is the feedback-free sample collection for enzyme immunoassay. As the measurement involves metabolites of the hormones rather than the hormones themselves, prior validation of the method is, however, necessary. This work reports on a study aiming to validate non-invasive measurement on the Madagascar Ground Gecko (Paroedura Picta). The validation was based on ACTH challenge test: Synacthen Depot was injected, which should lead to increased blood level of glucocorticoids. The validation, however, was not successful. The measurement did not discover significant increase in the levels of the metabolites of glucocorticoids. In addition, the work focuses on behavioural effects of testosterone, the primary androgen. Hormonal manipulations have been carried out on several male and female specimens. The results have discovered differences in sexual behaviour between control groups. On the other hand, the hormonal manipulations had no...
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