Total synthesis of a functional designer eukaryotic chromosome

Area of Science:

• Synthetic biology
• Genomics
• Molecular biology

Background:

• Advances in DNA synthesis enable engineering of genomes.
• Previous work has focused on bacterial genomes and viral systems.

Purpose of the Study:

• To design and synthesize a functional eukaryotic chromosome.
• To demonstrate genome engineering capabilities in eukaryotes.

Main Methods:

• Synthesized a 272,871-base pair designer chromosome (synIII) based on Saccharomyces cerevisiae chromosome III.
• Introduced modifications including stop-codon replacements, deletions of non-essential regions, and insertion of loxPsym sites.
• Tested functionality in S. cerevisiae and assessed chromosome scrambling effects.

Main Results:

• The synthetic chromosome synIII is functional in S. cerevisiae.
• Chromosome scrambling in a heterozygous diploid led to an increase in a-mating type derivatives.
• Loss of the MATα allele on synIII was observed after scrambling.

Conclusions:

• The successful design and synthesis of synIII demonstrate the feasibility of designer eukaryotic genome biology.
• This work establishes Saccharomyces cerevisiae as a platform for building designer eukaryotic genomes.
• Synthetic chromosomes offer new avenues for studying genome stability and function.