Compacting a synthetic yeast chromosome arm

Area of Science:

• Synthetic biology
• Genomics
• Molecular biology

Background:

• Genome redundancy ensures robustness but offers opportunities for minimization.
• The synthetic chromosome rearrangement and modification by loxP-mediated evolution (SCRaMbLE) system is key to the Sc2.0 synthetic yeast genome project.
• SCRaMbLE is explored for its potential in genome compaction and minimization.

Purpose of the Study:

• To develop and demonstrate a method for genome compaction using SCRaMbLE.
• To assess the efficiency of SCRaMbLE-based genome compaction (SGC) on a synthetic yeast chromosome arm (synXIIL).
• To identify essential and dispensable genes within the compacted genome.

Main Methods:

• Development of SCRaMbLE-based genome compaction (SGC).
• Utilizing an episomal essential gene array to enhance compaction efficiency.
• Employing iterative SGC and eArray for genome reduction.

Main Results:

• Efficient reduction of the synthetic chromosome arm (synXIIL) was achieved using SGC.
• An episomal essential gene array significantly boosted SGC's compacting ability.
• At least 39 out of 65 nonessential genes in synXIIL were removed without affecting cell viability at 30°C in rich medium.
• Approximately 40% of the synthetic sequence (28 genes) was found dispensable for growth under tested conditions.

Conclusions:

• Iterative SGC, aided by eArray, is a versatile tool for synthetic yeast genome compaction.
• The study successfully identified dispensable genes and pathways for specific growth conditions.
• This work advances genome minimization strategies within synthetic biology.