Project description:Analysis of copy number variation in evolved haploid, diploid, tetraploid strains. All experimental samples were compared to the same reference strain S288C. The samples include the progenitor strains for the haploid, diploid, and tetraploid evolution experiments, and single colony isolates (clones) from the evolving populations at given time points. Evolved clones were analyzed at generation 250 unless the name is followed by gen35, gen55 or gen500, in which case those generations were analyzed.
Project description:Haploid, diploid, and tetraploid yeast were experimentally evolved in 2% raffinose medium. After 250 generations, we assessed the gene expression alterations in 2 evolved haploids, 2 evolved diploids, and 4 evolved tetraploids relative to the diploid ancestor.
Project description:Polyploidy is observed across the tree of life, yet its influence on evolution remains incompletely understood. Polyploidy, usually whole-genome duplication, is proposed to alter the rate of evolutionary adaptation. This could occur through complex effects on the frequency or fitness of beneficial mutations. For example, in diverse cell types and organisms, immediately after a whole-genome duplication, newly formed polyploids missegregate chromosomes and undergo genetic instability. The instability following whole-genome duplications is thought to provide adaptive mutations in microorganisms and can promote tumorigenesis in mammalian cells. Polyploidy may also affect adaptation independently of beneficial mutations through ploidy-specific changes in cell physiology. Here we perform in vitro evolution experiments to test directly whether polyploidy can accelerate evolutionary adaptation. Compared with haploids and diploids, tetraploids undergo significantly faster adaptation. Mathematical modelling suggests that rapid adaptation of tetraploids is driven by higher rates of beneficial mutations with stronger fitness effects, which is supported by whole-genome sequencing and phenotypic analyses of evolved clones. Chromosome aneuploidy, concerted chromosome loss, and point mutations all provide large fitness gains. We identify several mutations whose beneficial effects are manifest specifically in the tetraploid strains. Together, these results provide direct quantitative evidence that in some environments polyploidy can accelerate evolutionary adaptation.
Project description:Citrus, one of the world’s most important crops is facing considerable challenges due to drought events. Previous studies have demonstrated that tetraploid rootstocks exhibit greater tolerance to abiotic stresses than their diploid counterparts. The effects of combining tetraploid rootstock with a triploid scion under water deficit treatment have not been thoroughly explored. A water deficit experiment was conducted in pot using four citrus scion/rootstock combinations: diploid and tetraploid Swingle citrumelo rootstocks grafted with diploid Mexican Lime and triploid Persian lime. Physiological, biochemical, and transcriptomic analyses revealed that scions grafted onto tetraploid rootstocks had significantly better drought tolerance, especially when combined with triploid Persian lime. This improved resilience was linked to enhanced water regulation, higher photosynthesis, increased stomatal conductance and transpiration during water stress. Elevated abscisic acid levels and stronger antioxidant activity in polyploid rootstocks further contributed to stress response. Transcriptomic data showed notable gene expression changes, providing insights into drought tolerance mechanisms. These findings underscore ploidy’s role at both the rootstock and scion levels in shaping the plant’s response to water deficit, revealing useful interactions between rootstock and scion influencing drought resilience. This study highlights the potential for leveraging polyploid rootstocks and scions to improve drought tolerance in citrus cultivation.
Project description:Using RNA-seq, we analyzed the transcriptomes of isogenic haploid (MATa) and tetraploid (MATaaaa) budding yeast strains in the Sigma 1278b background and identified genes whose regulation was altered by ploidy. Analysis of poly(A)+ RNA from 2 biological replicates of haploid (MATa) and tetraploid (MATaaaa) strains.
Project description:Using RNA-seq, we analyzed the transcriptomes of isogenic haploid (MATa) and tetraploid (MATaaaa) budding yeast strains in the Sigma 1278b background and identified genes whose regulation was altered by ploidy.
Project description:The aim of this study was to analyze the impact of autotetraploidy on gene expression in Arabidopsis thaliana by comparing diploid versus tetraploid transcriptomes. In particular, this included the comparison of the transcriptome of different tetraploid A. thaliana ecotypes (Col-0 vs. Ler-0). The study was extended to address further aspects. One was the comparison of the transcriptomes in subsequent generations. This intended to obtain information on the genome wide stability of autotetraploid gene expression. Another line of work compared the transcriptomes of different diploid vs. tetraploid tissues. This aimed to investigate whether particular gene groups are specifically affected during the development of A. thaliana autotetraploids. Samples 1-8: Arabidopsis thaliana Col-0 tetraploid transcriptome. Transcriptional profiling and comparison of diploid vs. tetraploid Col-0 seedlings. The experiment was carried out with pedigree of independently generated and assessed tetraploid Col-0 lines. Samples 9-12: Arabidopsis thaliana Ler-0 tetraploid transcriptome. Transcriptional profiling and comparison of diploid vs. tetraploid Ler-0 seedlings. The experiment was carried out with pedigree of independently generated and assessed tetraploid Ler-0 lines. Samples 13-24: Arabidopsis thaliana Col-0 tetraploid transcriptome. Transcriptional profiling and comparison of diploid vs. tetraploid Col-0 leaves (6th - 8th). The experiment was carried out with pedigree of independently generated and assessed tetraploid Col-0 lines. Samples 25-32: Arabidopsis thaliana Ler-0 tetraploid transcriptome. Transcriptional profiling and comparison of diploid vs. tetraploid Ler-0 leaves (6th - 8th). The experiment was carried out with pedigree of independently generated and assessed tetraploid Ler-0 lines. Samples 33-36: Arabidopsis thaliana Ler-0 tetraploid transcriptome. Transcriptional profiling and comparison of tetraploid vs. tetraploid Ler-0 seedlings from the second (F2) and third (F3) generation after induction, respectively. The experiment was carried out with pedigree of independently generated and assessed tetraploid Ler-0 lines. Samples 37-40: Arabidopsis thaliana Col-0 tetraploid transcriptome. Transcriptional profiling and comparison of tetraploid vs. tetraploid Col-0 seedlings from the second (F2) and third (F3) generation after induction, respectively. The experiment was carried out with pedigree of independently generated and assessed tetraploid Col-0 lines. Samples 41-44: Arabidopsis thaliana Col-0/Ler-0 diploid transcriptome. Transcriptional profiling and comparison of diploid Col-0 vs. diploid Ler-0 seedlings. The experiment was carried out with pedigree of esrablished lines. Samples 45-48: Arabidopsis thaliana Col-0/Ler-0 tetraploid transcriptome. Transcriptional profiling and comparison of tetraploid Col-0 vs tetraploid Ler-0 seedlings. The experiment was carried out with pedigree of independently generated and assessed tetraploid Col-0 and Ler-0 lines.