minichromosome
/ˈˌmɪnɪˈˌkrəʊməsəʊm/Genetics
noun
1A nucleoprotein complex consisting of viral DNA and histones and other proteins, formed in cells infected with certain viruses (chiefly papovaviruses).
2Any of various other small nucleoprotein structures, either naturally occurring (e.g. in certain bacteria and yeasts and in the fruit fly Drosophila melanogaster) or artificially constructed.
Origin
1970s. From mini- + chromosome.