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Y-chromosome The partner of the X-chromosome in the male of many animal species.
YAC Yeast artificial chromosome, used as a vector system for cloning DNA fragments that can be hundreds of kilobases long. Linear cloning vectors constructed from essential elements of yeast chromosomes. They can accommodate foreign DNA inserts of 200 to 500 kb.
yeast artificial chromosome See YAC.
yeast episomal vector (YEp) A cloning vector for the yeast Saccaromyces cerevisiae that uses 2mm plasmid as origin of replication and is maintained as an extrachromosomal nuclear DNA molecule.
yeast extract A mixture of substances from yeast. cf organic complex; undefined.
yeast A unicellular ascomycete fungus, commonly found as a contaminant in plant tissue culture.
yeast cloning vectors The yeasts, and especially Saccaromyces cerevisiae, are favourite organisms in which to clone and express DNA. They are eukaryotes, and so can splice out introns, the non-coding sequences in the middle of many eukaryotic genes.
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