The yeast artificial chromosome, which is often shortened to YAC, is an artificially constructed system that can undergo replication. The design of a YAC allows extremely large segments of genetic material to be inserted. Subsequent rounds of replication produce many copies of the inserted sequence, in a genetic procedure known as cloning.

The reason the cloning vector is called a yeast artificial chromosome has to do with the structure of the vector. The YAC is constructed using specific regions of the yeast chromosome. Yeast cells contain a number of chromosomes; organized collections of deoxyribonucleic acid (DNA). For example, the yeast Saccharomyces cerevisae contains 16 chromosomes that contain varying amounts of DNA. Each chromosome consists of two arms of DNA that are linked by a region known as the centromere. As the DNA in each arm is duplicated, the centromere provides a region of...