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Hybridisation of cyprinid fishes in the Czech Republic: genetic and morphometric analysis of the subfamily Leuciscinae
Kaufman, Vít ; Musilová, Zuzana (advisor) ; Choleva, Lukáš (referee)
Hybridization is a process when two interspecific individuals mate and spawn. When backcrossing it often goes hand in hand with admixing unrelated genome into the genome of a species. Nowadays it is well established that hybridization is not as uncommon as it was believed. Especially in vertebrates fish are quite common in such phenomena. In Leuciscids, the family of order Cypriniformes is relatively frequent. It is a rife family in the European freshwater systems. Factors that contribute to such frequent hybridization are extraneous fertilization, sympatric occurrence, competition for spawning grounds, and other ecophysiological traits. It was known since the second half of 20th century that this is an ongoing phenomenon in many species of this family. Previous research was focused mainly on morphological traits. The relative pinnacle of such research was based on allozymic analysis. The goal of our project was to evaluate the level of hybridization in the main water bodies of the Czech Republic with the main focus on the detection of involved hybrid species, the level of such hybridization, and the phenotypic characterization of hybrid individuals. For that reason, it was sampled over 400 specimens giving a dataset of 381 individuals. Tissue samples were sampled for DNA isolation and each of the...
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Evolution of visual sensory system in the common barbel (Barbus barbus)
Konvičková, Zuzana ; Musilová, Zuzana (advisor) ; Pergner, Jiří (referee)
Vertebrates inherited five visual opsin classes from their common ancestor expressed in the rod and cone cells. While many vertebrate groups reduced the number of visual pigments they possess, opsins of teleost fishes have diversified. Today, teleosts outstand among all vertebrates in the number of visual pigments and photoreceptor types. This extraordinary development was also facilitated by the teleost- specific whole genome duplication that occurred approximately 350 Mya. Here I explored teleost species that recently underwent subsequent whole genome duplication - the common barbel (Barbus barbus). This event was accompanied by hybridization (i.e., it was allopolyploidization) and resulted in 14 opsin genes found in the genome, an unusually high number even among teleosts. In this thesis, I studied the effects of such an expanded opsin repertoire on the visual abilities of the common barbel. Based on the whole genome, I have completed the reference sequences of all opsin genes and revealed their positions on the chromosomes. I analysed retinal transcriptomes and constructed developmental series of opsin expression profiles. All opsin genes were preserved functional in the genome, even though one of them (green-sensitive, named RH2-4 in this thesis) was not found in the transcriptome and showed...
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