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Evolution of karyotype and sex chromosomes in African and American clades of theraphosid mygalomorph spiders
Turečková, Eva ; Forman, Martin (advisor) ; Šťáhlavský, František (referee)
The family Theraphosidae (tarantulas) are generally known of spiders, often keept as hobby pets. Despite their popularity, many aspect of tarantula biology are still omitted. This include also cytogenetic research. In order, to fill this gap I analysed chromosomal constitution in 13 species of tarantulas belonging to the different genera from Africa and south/central America. Data set in this thesis included, also, the tarantula with so far the best covered genome Acanthoscuria genicullata, and the iconic, giant spider Theraphosa stirmi. Conventional giemsa staining of male meiotic plates was accompanied with visualisation of major rRNA clusters using fluorescence in situ hybridization with 18S rDNA probe. Diploid counts ranges considerably from 31 (Ceratogyrus meridionalis) to 83 (Theraphosa stirmi). In some specimens presence of multivalents indicated a possibility of hybridization of different chromosomal races in a hobby lineages. Various types of differentiated sex chromosomes have been proven, including X0, X1X20 X1X2X30 systems. Interestingly, the diversity in karyotype features was not linked with diversity in major rDNA cluster number. Most of the species displayed one prominent locus located on autosomes. Two species exhibited polymorphism in the presence of one more additive smaller...
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