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Evolution of sex chromosomes and karyotypes in geckos (Squamata: Gekkota)
Koubová, Martina ; Kratochvíl, Lukáš (advisor) ; Choleva, Lukáš (referee)
Gekkota is species-rich and diverse group of squamate reptiles (Reptilia: Squamata) with almost global distribution. There were many hypothesis defined about the phylogeny of this group, traditionally based on morphological data. The essential reversal in phylogenetic relationships occurred with the entry of molecular analysis, whose differ in their conclusions from traditional approach fundamentally, even in positions of mayor lineages. This fact has an essential importance for the karyotype evolution study of this group. The ancestral state is considered as 2n=38 karyotype with all chromosomes acrocentric. In some species is this karyotype kept, in another there is apparent an influence of chromosome changes, mostly Robertsonian fusions and pericentric inversions. Diploid chromosome number is from 16 to 46, but the most common is 2n=38 karyotype of mostly acrocentric chromosomes, gradually decreasing in size. The interesting character of this group is extraordinary variability in sex determining mechanisms. We can find there species with temperature sex determination and also species with genotypic sex determination (both types XX/XY and ZZ/ZW). Sex chromosomes data are documented in only 17 species. Sex chromosomes differ rapidly in their morphology and their homology between sister taxa was not proved...
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Reliability of Klales et al. (2012) method for sex assessment from hip bone based on CT imaging
Firlová, Radka ; Brůžek, Jaroslav (advisor) ; Galeta, Patrik (referee)
The study is primarily focused on testing of the method which assesses sex from pubis. This method was originally proposed by Phenice (1969). Klales et al. (2012) modified this method in their study. They suggested to improve of the Phenice (1969) technique by extending the evaluation scale of three morphological traits from two values - present / absent to five development stage. Our study assumes that the success of Phenice (1969) method is related to the degree of sexual dimorphism of evaluated population. So the extension of evaluation scale will not lead to increased accuracy and will occur to decrease relibility of the method also. Intraobserver error was evaluated for Phenice (1969) a Klales et al. (2012) methods on the sample of isolated pelvic bones from Department of anthropology and human genetics of Charles university in Praque in first time. After we evaluated the whole sample, which consist of 200 three-dimensional models of pelvic bones. These models were segmented from CT images of adult individuals from contemporary French population. This sample was statistically evaluated by Cohen kappa, accuracy, senzitivity and specificity using confusion matrix and relationship between specificita and senzitivity was tested by ROC curves and area under curve (AUC). Results show that Phenice...
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Reliability of Klales et al. (2012) method for sex assessment from hip bone based on CT imaging
Firlová, Radka ; Brůžek, Jaroslav (advisor) ; Galeta, Patrik (referee)
The study is primarily focused on testing of the method which assesses sex from pubis. This method was originally proposed by Phenice (1969). Klales et al. (2012) modified this method in their study. They suggested to improve of the Phenice (1969) technique by extending the evaluation scale of three morphological traits from two values - present / absent to five development stage. Our study assumes that the success of Phenice (1969) method is related to the degree of sexual dimorphism of evaluated population. So the extension of evaluation scale will not lead to increased accuracy and will occur to decrease relibility of the method also. Intraobserver error was evaluated for Phenice (1969) a Klales et al. (2012) methods on the sample of isolated pelvic bones from Department of anthropology and human genetics of Charles university in Praque in first time. After we evaluated the whole sample, which consist of 200 three-dimensional models of pelvic bones. These models were segmented from CT images of adult individuals from contemporary French population. This sample was statistically evaluated by Cohen kappa, accuracy, senzitivity and specificity using confusion matrix and relationship between specificita and senzitivity was tested by ROC curves and area under curve (AUC). Results show that Phenice...
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Evolution of sex chromosomes and karyotypes in geckos (Squamata: Gekkota)
Koubová, Martina ; Kratochvíl, Lukáš (advisor) ; Choleva, Lukáš (referee)
Gekkota is species-rich and diverse group of squamate reptiles (Reptilia: Squamata) with almost global distribution. There were many hypothesis defined about the phylogeny of this group, traditionally based on morphological data. The essential reversal in phylogenetic relationships occurred with the entry of molecular analysis, whose differ in their conclusions from traditional approach fundamentally, even in positions of mayor lineages. This fact has an essential importance for the karyotype evolution study of this group. The ancestral state is considered as 2n=38 karyotype with all chromosomes acrocentric. In some species is this karyotype kept, in another there is apparent an influence of chromosome changes, mostly Robertsonian fusions and pericentric inversions. Diploid chromosome number is from 16 to 46, but the most common is 2n=38 karyotype of mostly acrocentric chromosomes, gradually decreasing in size. The interesting character of this group is extraordinary variability in sex determining mechanisms. We can find there species with temperature sex determination and also species with genotypic sex determination (both types XX/XY and ZZ/ZW). Sex chromosomes data are documented in only 17 species. Sex chromosomes differ rapidly in their morphology and their homology between sister taxa was not proved...
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