Pichia sorbitophila, an Interspecies Yeast Hybrid, Reveals Early Steps of Genome Resolution After Polyploidization
نویسندگان
چکیده
Polyploidization is an important process in the evolution of eukaryotic genomes, but ensuing molecular mechanisms remain to be clarified. Autopolyploidization or whole-genome duplication events frequently are resolved in resulting lineages by the loss of single genes from most duplicated pairs, causing transient gene dosage imbalance and accelerating speciation through meiotic infertility. Allopolyploidization or formation of interspecies hybrids raises the problem of genetic incompatibility (Bateson-Dobzhansky-Muller effect) and may be resolved by the accumulation of mutational changes in resulting lineages. In this article, we show that an osmotolerant yeast species, Pichia sorbitophila, recently isolated in a concentrated sorbitol solution in industry, illustrates this last situation. Its genome is a mosaic of homologous and homeologous chromosomes, or parts thereof, that corresponds to a recently formed hybrid in the process of evolution. The respective parental contributions to this genome were characterized using existing variations in GC content. The genomic changes that occurred during the short period since hybrid formation were identified (e.g., loss of heterozygosity, unilateral loss of rDNA, reciprocal exchange) and distinguished from those undergone by the two parental genomes after separation from their common ancestor (i.e., NUMT (NUclear sequences of MiTochondrial origin) insertions, gene acquisitions, gene location movements, reciprocal translocation). We found that the physiological characteristics of this new yeast species are determined by specific but unequal contributions of its two parents, one of which could be identified as very closely related to an extant Pichia farinosa strain.
منابع مشابه
Isolation and characterisation of mutants from the halotolerant yeast Pichia sorbitophila defective in H+/glycerol symport activity.
Pichia sorbitophila, a yeast species that is highly resistant to osmotic stress in general and to salt stress in particular, was subjected to a mutagenesis strategy in order to obtain mutants deficient in the glycerol active uptake previously described. Density centrifugation was used for enrichment of NaCl sensitive mutants in either glucose or glycerol media. Several phenotypic classes of mut...
متن کاملP-205: Production of Recombinant Fish FSH Hormone in Pichia Pastoris
Background: Follicle-stimulating hormone (FSH) belongs to the family of glycoprotein hormones that composing alpha and beta subunits with non-covalently bonds. This hormone involve in regulation of the reproductive processes such as gamete generation and follicular growth. Injection of the hormone in most of fish species increases 17 beta-estradiol production by ovarian tissue and also stimulat...
متن کاملEvolutionary restoration of fertility in an interspecies hybrid yeast, by whole-genome duplication after a failed mating-type switch
Many interspecies hybrids have been discovered in yeasts, but most of these hybrids are asexual and can replicate only mitotically. Whole-genome duplication has been proposed as a mechanism by which interspecies hybrids can regain fertility, restoring their ability to perform meiosis and sporulate. Here, we show that this process occurred naturally during the evolution of Zygosaccharomyces para...
متن کاملExperimental Evolution Reveals Interplay between Sch9 and Polyploid Stability in Yeast
Polyploidization has crucial impacts on the evolution of different eukaryotic lineages including fungi, plants and animals. Recent genome data suggest that, for many polyploidization events, all duplicated chromosomes are maintained and genome reorganizations occur much later during evolution. However, newly-formed polyploid genomes are intrinsically unstable and often quickly degenerate into a...
متن کاملPichia stipitis genomics, transcriptomics, and gene clusters
Genome sequencing and subsequent global gene expression studies have advanced our understanding of the lignocellulose-fermenting yeast Pichia stipitis. These studies have provided an insight into its central carbon metabolism, and analysis of its genome has revealed numerous functional gene clusters and tandem repeats. Specialized physiological traits are often the result of several gene produc...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره 2 شماره
صفحات -
تاریخ انتشار 2012