GEPHE SUMMARY Print
Gephebase Gene
Entry Status
Published
GepheID
GP00000651
Main curator
Martin
PHENOTYPIC CHANGE
Trait Category
Trait State in Taxon A
Saccharomyces cerevisiae
Trait State in Taxon B
Saccharomyces uvarum
Ancestral State
Data not curated
Taxonomic Status
Taxon A
Common Name
baker's yeast
Synonyms
Saccharomyces capensis; Saccharomyces italicus; Saccharomyces oviformis; Saccharomyces uvarum var. melibiosus; baker's yeast; S. cerevisiae; brewer's yeast; ATCC 18824; ATCC:18824; CBS 1171; CBS:1171; NRRL Y-12632; NRRL:Y:12632; Saccaromyces cerevisiae; Saccharomyce cerevisiae; Saccharomyes cerevisiae; Sccharomyces cerevisiae
Rank
species
Lineage
cellular organisms; Eukaryota; Opisthokonta; Fungi; Dikarya; Ascomycota; saccharomyceta; Saccharomycotina; Saccharomycetes; Saccharomycetales; Saccharomycetaceae; Saccharomyces
NCBI Taxonomy ID
is Taxon A an Infraspecies?
No
Taxon B
Common Name
-
Synonyms
Saccharomyces bayanus var. uvarum; Saccharomyces globosus; Saccharomyces bayanus var. uvarum (Beij.) G.I. Naumov; Saccharomyces globosus Osterw., 1924; Saccharomyces uvarum Beij. 1898; BCRC:21964; BCRC:21970; CBS 395; CBS 424; CBS:395; CBS:424; CCRC 21964; CCRC 21970; CCRC:21964; CCRC:21970; CLIB 250; CLIB 251; CLIB:250; CLIB:251; DBVPG 6115; DBVPG 6179; DBVPG:6115; DBVPG:6179; DSM 70547; DSM:70547; IFO 0254; IFO 0615; IFO 10557; IFO 11025; IFO:0254; IFO:0615; IFO:10557; IFO:11025; IGC 4567; IGC 4568; IGC:4567; IGC:4568; NCYC 509; NCYC:509; NRRL Y-12645; NRRL Y-12663; NRRL Y-17034; NRRL:Y:12645; NRRL:Y:12663; NRRL:Y:17034
Rank
species
Lineage
cellular organisms; Eukaryota; Opisthokonta; Fungi; Dikarya; Ascomycota; saccharomyceta; Saccharomycotina; Saccharomycetes; Saccharomycetales; Saccharomycetaceae; Saccharomyces
NCBI Taxonomy ID
is Taxon B an Infraspecies?
No
GENOTYPIC CHANGE
Generic Gene Name
MEP2
Synonyms
AMT2; YNL142W; N1207; N1820
Sequence Similarities
Belongs to the ammonia transporter channel (TC 1.A.11.2) family.
UniProtKB
Saccharomyces cerevisiae (strain ATCC 204508 / S288c)
GenebankID or UniProtKB
Presumptive Null
No
Molecular Type
Aberration Type
Molecular Details of the Mutation
Chimeric gene in diploid hybrids formed by recombination between the parental alleles
Experimental Evidence
Authors
Dunn B; Paulish T; Stanbery A; Piotrowski J; Koniges G; Kroll E; Louis EJ; Liti G; et al. ... show more
Abstract
Genome rearrangements are associated with eukaryotic evolutionary processes ranging from tumorigenesis to speciation. Rearrangements are especially common following interspecific hybridization, and some of these could be expected to have strong selective value. To test this expectation we created de novo interspecific yeast hybrids between two diverged but largely syntenic Saccharomyces species, S. cerevisiae and S. uvarum, then experimentally evolved them under continuous ammonium limitation. We discovered that a characteristic interspecific genome rearrangement arose multiple times in independently evolved populations. We uncovered nine different breakpoints, all occurring in a narrow ~1-kb region of chromosome 14, and all producing an "interspecific fusion junction" within the MEP2 gene coding sequence, such that the 5' portion derives from S. cerevisiae and the 3' portion derives from S. uvarum. In most cases the rearrangements altered both chromosomes, resulting in what can be considered to be an introgression of a several-kb region of S. uvarum into an otherwise intact S. cerevisiae chromosome 14, while the homeologous S. uvarum chromosome 14 experienced an interspecific reciprocal translocation at the same breakpoint within MEP2, yielding a chimaeric chromosome; these events result in the presence in the cell of two MEP2 fusion genes having identical breakpoints. Given that MEP2 encodes for a high-affinity ammonium permease, that MEP2 fusion genes arise repeatedly under ammonium-limitation, and that three independent evolved isolates carrying MEP2 fusion genes are each more fit than their common ancestor, the novel MEP2 fusion genes are very likely adaptive under ammonium limitation. Our results suggest that, when homoploid hybrids form, the admixture of two genomes enables swift and otherwise unavailable evolutionary innovations. Furthermore, the architecture of the MEP2 rearrangement suggests a model for rapid introgression, a phenomenon seen in numerous eukaryotic phyla, that does not require repeated backcrossing to one of the parental species.
Additional References
RELATED GEPHE
Related Haplotypes
No matches found.
EXTERNAL LINKS
COMMENTS
@Introgression
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