Genetic structure of the Daphnia longispina complex in European mountain lakes

I studied the genetic structure of cladocerans from the Daphnia longispina complex in several European mountain ranges. The population genetic structure of the D. longispina complex was studied using mitochondrial (mtDNA; partial sequencing of the 12S rRNA gene) and nuclear markers (nine microsatellite loci). Major part of the work was done in the Tatra Mountains; the genetic structure of populations of the Daphnia longispina complex from two parts of this range (the West and the High Tatras) was compared. The pattern of mtDNA confirmed multiple colonization of lakes from different source populations, detected haplotype diversity was high and haplotype sharing only within the West or the High Tatras was observed. The observed genetic differentiation indicates low level of gene flow and persistent founder effect, consistent with the monopolization hypothesis. The alternation of asexual and sexual reproduction in the life cycle of Daphnia, cyclical parthenogenesis, may affect genetic structure of their populations. This was the topic of a study described in the first chapter. A detailed analysis of population structure of two closely related Daphnia species (D. galeata and D. longispina) living in similar habitats (permanent dimictic mountain lakes) in the Tatra Mountains revealed that populations..