Complete genome assembly data of paenibacillus sp. RUD330, a hypothetical symbiont of euglena gracilis.

An unknown bacterial strain was detected in the cytostome of Euglena gracilis and on the cell surface of Euglena gracilis using transmission electron microscopy. To identify the unknown bacterium and its function, we performed isolation experiments. Here we present the genome sequence of the isolate that was determined to be Paenibacillus sp. The genome of the bacterium was sequenced four times using Illumina technology with pair-end reads, Illumina technology with mate pair reads (inserts 3-4 and 6-8 Kb), and Nanopore technology with long reads (tens of thousands of nucleotides). Assemblies based on Illumina reads including mate-pair reads could not resolve issues caused by long tandem copies of rRNA, other tandem repeats, and extremely GC-rich regions (90-100%). Only long Nanopore reads resolved those gaps and made it possible to complete the entire genome; moreover, we found one plasmid. The length of the genome is 5.56 Mbp, and the average GC content is 59%. The genome of Paenibacillus sp. RUD330 included 8 copies of all the rRNA genes (23S; 16S; 5S), the length of the plasmid was 8.3 Kb. We hope that our genome assembly and the methods used can help other investigators in the assembly of complex genomes. Our reliable assembly could be a good basis for further physiological and genetic engineering studies of similar strains.

Common Structural Patterns in the Maxicircle Divergent Region of Trypanosomatidae.

Maxicircles of all kinetoplastid flagellates are functional analogs of mitochondrial genome of other eukaryotes. They consist of two distinct parts, called the coding region and the divergent region (DR). The DR is composed of highly repetitive sequences and, as such, remains the least explored segment of a trypanosomatid genome. It is extremely difficult to sequence and assemble, that is why very few full length maxicircle sequences were available until now. Using PacBio data, we assembled 17 complete maxicircles from different species of trypanosomatids. Here we present their large-scale comparative analysis and describe common patterns of DR organization in trypanosomatids.