yeast-congress-2018-posters-abstracts

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alliedacademies
Archives of Industrial Biotechnology | Volume 2
May 14-15, 2018 | Montreal, Canada
World Yeast Congress
For many years, it was accepted that the Saccharomyces
cerevisiae (S. cerevisiae) lineage arose from a Whole
Genome Duplication (WGD), making this yeast an interesting
model to study diversificationof paralogous genes. Recently, a
phylogenetic study found compelling evidence indicating that
S. cerevisiae lineage arose from an interspecies hybridization
between one strain related to the Kluyveromyces, Lachancea
and Eremothecium (KLE) clade and another one related to
Zygosaccharomyces rouxii and Torulaspora delbrueckii (ZT).
Although whether the hybrid was the result of the fusion
of two diploid cells or two haploid cells that underwent
a WGD, is still an open question, both scenarios result
in the formation of an allotetraploid with two copies of
every gene. After the allotetraploid was formed, intragenic
recombinations, full gene conversion, differential gene
loss and selection pressures shaped S. cerevisiae genome
to the one we observe today, harboring conserved blocks
of duplicated genes. Retained duplicate genes (paralogs)
can simply provide increased dosage of the same protein,
or may go through a process of subfunctionalization or
neofunctionalization, in which both copies of the gene lose
a subset of their ancestral functions, while acquiring new
properties. S. cerevisiae has been used as a model organism
to analyze gene duplication dynamics and the functional
fates of duplicated genes. In this conference I will present
and discuss functional diversification pathways of three
paralogous gene pairs, whose products are involved in
amino acid metabolism and whose sub-subfunctionalization
led to the separation and specialization of the ancestral
function between the two duplicated genes. Examples of
the subfunctionalization of paralogous pairs which was been
achieved through: i) modifications of the coding sequence
leading to paralogous proteins with particular kinetic
properties (GDH1/GDH3), ii) modifications of the regulatory
region determining differential expression of each gene copy
BAT1/BAT2 leading to the specialized functions of Bat1 and
Bat2 encoded transaminases, and iii) selective organization
of homo or hetero-oligomeric isozymes with peculiar
biochemical properties (LEU4/LEU9), will be presented and
the functional repercussion of diversification will be amply
discussed.
e:
Evolutionary Diversification of Paralogous Genes in the yeast Saccharomyces cerevisiae: Its
Physiological Role
Alicia González
Universidad Nacional Autónoma de México