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Unformatted text preview: 5 A.1 An Overview of Yeast in the Laboratory which there are about 50 dispersed complete copies per
haploid genome. In addition, there are 385 incomplete dispersed copies that contain only the ends of the intact Ty elements (called long terminal repeats, or LTRs). S. cerevisiae Evolved
from a Duplicated Genome
It has become clear from sequence analysis of S. cerevisiae
and the yeast Kluveromyces waltii that the yeast genome
evolved after the whole-genome duplication of an ancestral
species followed by gene loss, reciprocal translocations and
other large-scale rearrangements. One theory explaining the
structure of the modern yeast genome is that the organism
evolved from an ancestral degenerate tetraploid. This
tetraploid resulted from whole-genome duplication that occurred perhaps 100 million years ago, after the divergence
of Saccharomyces and the related yeast Kluveromyces. Following the whole-genome duplication, many segments of
the duplicated chromosomes were deleted, mutated, and rearranged by reciprocal translocations between nonhomologous chromosom...
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This note was uploaded on 10/03/2013 for the course BI 206 taught by Professor Celenza during the Spring '08 term at BU.
- Spring '08