Abstract
Diplonemids, a sister clade of kinetoplastid flagellates, were recently identified as the most diverse marine eukaryotes which also rank as the 6th most abundant eukaryotic group. However, only a very few species have been described and we know nothing about their life style. To fill the large gap in our knowledge, we embarked on the studies of diplonemid diversity and distribution, morphology and life cycles. We are also assembling and annotating their transcriptomes and genomes that share some features with related kinetoplastids, but differ from them by f.e. abundant presence of introns. We are also trying to get representative species into the culture. Moreover, we were recently able to transform Diplonema papillatum and are turning it into a tractable organism suitable for functional analyses.