Person:
Yant, Levi

Profile Picture

Email Address

AA Acceptance Date

Birth Date

Research Projects

Organizational Units

Job Title

Last Name

Yant

First Name

Levi

Name

Yant, Levi

Filters

2010 - 20133

Settings

Author's Publications: search.filters.isAuthorOfPublication.ba1f630b-b17f-4e26-b220-e0dfb08ed956

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Publication
    Meiotic Adaptation to Genome Duplication in Arabidopsis arenosa
    (Elsevier BV, 2013) Yant, Levi; Hollister, J; Wright, K; Arnold, Brian; Higgins, James D.; Franklin, F. Chris H.; Bomblies, Kirsten
    Whole genome duplication (WGD) is a major factor in the evolution of multicellular eukaryotes, yet by doubling the number of homologs, WGD severely challenges reliable chromosome segregation [1, 2, 3], a process conserved across kingdoms [4]. Despite this, numerous genomeduplicated (polyploid) species persist in nature, indicating early problems can be overcome [1, 2]. Little is known about which genes are involved – only one has been molecularly characterized [5]. To gain new insights into the molecular basis of adaptation to polyploidy, we investigated genome-wide patterns of differentiation between natural diploids and tetraploids of Arabidopsis arenosa, an outcrossing relative of A. thaliana [6, 7]. We first show that diploids are not preadapted to polyploid meiosis. We then use a genome scanning approach to show that while polymorphism is extensively shared across ploidy levels, there is strong ploidy-specific differentiation in 39 regions spanning 44 genes. These are discrete, mostly single-gene peaks of sharply elevated differentiation. Among these peaks are eight meiosis genes whose encoded proteins coordinate a specific subset of early meiotic functions, suggesting these genes comprise a polygenic solution to WGD-associated chromosome segregation challenges. Our findings indicate that even conserved meiotic processes can be capable of nimble evolutionary shifts when required.
  • Thumbnail Image
    Publication
    Genetic Architecture of Flowering-Time Variation in Arabidopsis thaliana
    (The Genetics Society of America, 2011) Salomé, Patrice A.; Bomblies, Kirsten; Laitinen, Roosa A.; Yant, Levi; Mott, Richard; Weigel, Detlef
    The onset of flowering is an important adaptive trait in plants. The small ephemeral species Arabidopsis thaliana grows under a wide range of temperature and day-length conditions across much of the Northern hemisphere, and a number of flowering-time loci that vary between different accessions have been identified before. However, only few studies have addressed the species-wide genetic architecture of flowering time control. We have taken advantage of a set of 18 distinct accessions that present much of the common genetic diversity of A. thaliana and mapped quantitative trait loci (QTL) for flowering time in 17 \(F_2\) populations derived from these parents. We found that the majority of flowering-time QTL cluster in as few as five genomic regions, which include the locations of the entire FLC/MAF clade of transcription factor genes. By comparing effects across shared parents, we conclude that in several cases there might be an allelic series caused by rare alleles. While this finding parallels results obtained for maize, in contrast to maize much of the variation in flowering time in A. thaliana appears to be due to large-effect alleles.
  • Thumbnail Image
    Publication
    Local-Scale Patterns of Genetic Variability, Outcrossing, and Spatial Structure in Natural Stands of Arabidopsis thaliana
    (Public Library of Science, 2010) Bomblies, Kirsten; Yant, Levi; Laitinen, Roosa A.; Kim, Sang-Tae; Hollister, J; Warthmann, Norman; Fitz, Joffrey; Weigel, Detlef
    As Arabidopsis thaliana is increasingly employed in evolutionary and ecological studies, it is essential to understand patterns of natural genetic variation and the forces that shape them. Previous work focusing mostly on global and regional scales has demonstrated the importance of historical events such as long-distance migration and colonization. Far less is known about the role of contemporary factors or environmental heterogeneity in generating diversity patterns at local scales. We sampled 1,005 individuals from 77 closely spaced stands in diverse settings around Tübingen, Germany. A set of 436 SNP markers was used to characterize genome-wide patterns of relatedness and recombination. Neighboring genotypes often shared mosaic blocks of alternating marker identity and divergence. We detected recent outcrossing as well as stretches of residual heterozygosity in largely homozygous recombinants. As has been observed for several other selfing species, there was considerable heterogeneity among sites in diversity and outcrossing, with rural stands exhibiting greater diversity and heterozygosity than urban stands. Fine-scale spatial structure was evident as well. Within stands, spatial structure correlated negatively with observed heterozygosity, suggesting that the high homozygosity of natural A. thaliana may be partially attributable to nearest-neighbor mating of related individuals. The large number of markers and extensive local sampling employed here afforded unusual power to characterize local genetic patterns. Contemporary processes such as ongoing outcrossing play an important role in determining distribution of genetic diversity at this scale. Local “outcrossing hotspots” appear to reshuffle genetic information at surprising rates, while other stands contribute comparatively little. Our findings have important implications for sampling and interpreting diversity among A. thaliana accessions.