Rozplétání složité evoluční historie pohlavních chromozomů hadů

Pšenička, Tomáš

Sex chromosomes can be a dynamic, fast-evolving part of the genome and one that follows slightly different evolutionary pathways than the autosomes. They have evolved independently many times in the great diversity of eukaryotes, representing a case of incredible convergence on the genomic level. One of the most influential theories about sex chromosome evolution was inspired by sex chromosomes of snakes, a well-recognized and species-rich group of squamate reptiles. Due to the cytogenetic studies conducted several decades ago, it was widely accepted that all snakes share homologous and evolutionary stable ZZ/ZW sex chromosomes that are differentiated in the diverse group of caenophidian snakes and only poorly differentiated in the other lineages, where they were not detected. Recent advances have, however, proven the sex chromosome evolution in snakes more complex with the discovery of two non-homologous XX/XY sex chromosome systems in non-caenophidian snakes. This thesis is focused on uncovering sex chromosome systems in snake lineages where direct evidence for them was missing. In addition, it aimed to explore the satellite DNA content in the genomes of members of the family Erycidae. A combination of cytogenetic, molecular and bioinformatic methods was used to detect even poorly differentiated...

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