National Repository of Grey Literature 2 records found  Search took 0.00 seconds. 
The sex determination in the gecko genus Phelsuma
Peš, Tomáš ; Kratochvíl, Lukáš (advisor) ; Kverková, Kristina (referee)
Geckos (Gekkota) are a diverse group of squamate reptiles. The species richness of geckos is associated with a wide variety of sex determination systems. We can encounter male and female heterogamety, environmental sex determination, or asexuality in this group of reptiles. The diversity of geckos makes this group very interesting for studying of the evolution of sex determination. Due to the large number of species, we know the type of sex determination in just a fraction of taxa. The genus Phelsuma has been little studied in this respect and, with one exception, published data are not very reliable. In this thesis, sex determination in Phelsuma laticauda and Phelsuma nigristriata was investigated using an incubation experiment. I proved that both species have environmental sex determination. The effect of incubation temperature on morphological characteristics was also investigated in hatchlings. The possible persistence of this effect into adulthood was re-tested in one year old geckos.
Developmental plasticity in reptiles
Peš, Tomáš ; Kratochvíl, Lukáš (advisor) ; Frýdlová, Petra (referee)
The environment during incubation can have significant influence upon phenotype of reptile hatchlings. Temperature is one of the main environmental factors affecting developing embryos. The response to variability in the environment can be diverse: short, long-lasting and potentially also sex-specific. A large number of studies focused on this phenomenon but only a small portion of them studied the persistence of the phenotypic effects. I summarized studies on the influence of environmental factors on the phenotype of reptiles in species with both temperature or genotypic sex determination. These studies were evaluated in terms of duration of these effects and if these are sex specific. I also assessed how much they correspond with the predictions of the adaptive model suggested by Charnov & Bull which explains the origin and maintenance of temperature sex determination. Key words: phenotypic plasticity, environment, development, behaviour, morphology, sex determination, phenotype

Interested in being notified about new results for this query?
Subscribe to the RSS feed.