Lodderomyces elongisporus genomic DNA treated by BAL-31

We analyzed telomeric repeats of the yeast Lodderomyces elongisporus strain CBS 5301 using the BAL31-NGS protocol by Peska et al 2017. High-molecular-weight genomic DNA was extracted from cells. A control sample is sequenced unmodified, whereas a second portion is first digested with BAL-31 nuclease, which degrades and cleaves at double-stranded DNA from both termini nicks and single-stranded regions. Chromosome ends (natural double-stranded breaks) will be degraded in all chromosomal copies and thus will be underrepresented in sequencing reads compared to the control sample. We digested our treated samples with 1 and 2 U of BAL-31 (New England Biolabs) in 50µl of 1x BAL-31 reaction buffer at 30°C for 15 min. The sequencing library was prepared using a Rapid Barcoding kit (Oxford Nanopore Technologies SQK-RBK004), sequenced on a MinION MK-1b with a FLO-MIN106 (R9.4.1) flowcell and basecalled using Guppy v.4.4.1.