A Yeast Artificial Chromosome (YAC) insert can be exceptionally large, up to 2,000 kilobases (kb) in size.
YACs are specialized cloning vectors designed to carry very large fragments of DNA. Their ability to accommodate such substantial inserts makes them invaluable tools in genetic engineering and genomic research, particularly for mapping and sequencing large genomes.
Understanding YAC Insert Capacity
YACs are constructed to mimic the structure and function of a natural yeast chromosome, enabling them to replicate stably within yeast cells. This unique design allows them to hold significantly larger DNA segments compared to other common cloning vectors. The large capacity of YACs is a primary reason for their use in constructing comprehensive genomic libraries.
To put the insert size of a YAC into perspective, consider its capacity alongside other widely used cloning vectors:
| Vector | Maximum Insert Size (kilobases) |
|---|---|
| P1 plasmid vector | 100 |
| PAC (P1 artificial chromosome) | 150 |
| BAC (Bacterial artificial chromosome) | 300 |
| YAC (Yeast artificial chromosome) | 2,000 |
As shown, a YAC can carry DNA fragments many times larger than bacterial artificial chromosomes (BACs), P1 artificial chromosomes (PACs), or traditional P1 plasmid vectors. This enormous capacity allows researchers to clone and analyze entire genes, gene clusters, or even large chromosomal regions in a single insert, simplifying complex genomic studies.
