Issa Diop from the University of Zurich in Switzerland presented at London Calling 2021 on “Chromosomal-scale assembly of the liverwort Marchantia paleacea.” Diop discussed chloroplasts and endosymbionts before introducing Marchantia as a model of plant evolution. Marchantia has a haploid-dominant life cycle with a genome size of 280 Mbp. There are eight autosomes and 1 sex chromosome. Importantly, there are tools for genetic manipulation. This plant also has both vegetative and sexual reproduction. Diop explained that obtaining high-quality DNA was a challenge. They used beads with g-TUBE shearing and CTAB without shearing. They then obtained high-quality DNA and sequenced it with the ligation sequencing kit LSK-109 on a GridION. They used four flow cells and obtained two million reads and about 12 Gb. The N50 was over 17 Kb. The assembly resulted in 277 contigs. This number was improved with filtering. Dovetail HiRise Assembly helped obtain better scaffolds. They annotated the genome and compared the unique genes. The team began investigating disease susceptibility and plant-microbe interactions with the annotated sequences.
