<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>Chromosomes in which fragments of exogenous DNA ranging in length up to several hundred kilobase pairs have been cloned into yeast through ligation to vector sequences. These artificial chromosomes are used extensively in molecular biology for the construction of comprehensive genomic libraries of higher organisms.</n0:def-definition><n0:def-source>MSH2002_06_01</n0:def-source></n0:ComplexDefinition>
<n0:ComplexDefinition xmlns:n0="http://ncicb.nci.nih.gov/xml/owl/EVS/ComplexProperties.xsd#"><n0:def-definition>A cloning vector based upon elements of yeast chromosomes. At a minimum these include: yeast telomeres, a yeast centromere, and a yeast autonomously replicating sequence (ARS). Such vectors are propagated in yeast and then transferred into a target eukaryotic cell where the yeast sequences can be recognized and will maintain the molecule through cell division. These vectors can maintain extremely large amounts of foreign DNA. YACs are maintained as linear molecules</n0:def-definition><n0:def-source>NCI</n0:def-source></n0:ComplexDefinition>