Abstract Detail

Comparative Genomics/Transcriptomics

Ostovar, Talieh [1], Landis, Jacob [2], McCarthy, Elizabeth [3], Stajich, Jason [4], Waters, Elizabeth [5], Litt, Amy [6].

Impacts of allopolyploidy on gene expression in Nicotiana section Repandae.

Genome duplication along with hybridization of two diploid species (allopolyploidy) is a common phenomenon among flowering plants that produces an allotetraploid species with two homoeologous sub-genomes. Allopolyploidy has been a powerful force in the evolution of angiosperms, affecting diversification and speciation with profound effects on plant genome structure and gene expression. Therefore, to better understand the short- and long-term consequences of allopolyploidization, investigating global expression patterns of allopolyploids and their progenitor species and the extent to which allopolyploidy causes novel gene expression patterns is of high importance. Nicotiana (Solanaceae) is a well-characterized genus and about half of the Nicotiana species are recognized as allopolyploids of different ages. Thus, it is an ideal genus to study the evolutionary processes that accompany allopolyploidization. Here, we explore the impact of allopolyploidy on transcriptome dynamics in Nicotiana section Repandae. This section includes three allopolyploid species, N. nudicaulis, N. repanda and N. stocktonii, derived from hybridization between N. sylvestrisand N. obtusifolia as the diploid progenitor species. We have used a comparative transcriptomics approach using leaf and corolla tissues to identify genes with differential expression across tetraploid and diploid species, as well as across stages of corolla development within each species. Clustering of overall gene expression based on species and tissue types shows clear differences in expression between the two progenitor species. More importantly, the polyploids have intermediate expression compared to the two parental species with a potential bias to N. obtusifolia. Furthermore, the most common pattern of gene expression across corolla developmental stages seems to vary among different species. These results will be used to perform functional term analysis and find the associated Gene Ontology (GO) terms and finally to identify potential candidate genes for underlying variation in phenotype. This study will give us a broad understanding of gene expression response to allopolyploidy and ultimately how it changes over the course of evolutionary time.

1 - San Diego State University, Biology, San Diego, CA
2 - Cornell University
3 - SUNY Cortland, Department Of Biological Sciences, P.O. Box 2000, Cortland, NY, 13045, United States
4 - University Of California-Riverside, Dept Plant Pathology And Microbiology, 900 University Ave, Riverside, CA, 92521.0, United States
5 - San Diego State University, Biology, 5500 Campanille Drive, San Diego, CA, 92182, United States
6 - University Of California Riverside, Botany Dept, 900 University Ave, Riverside, CA, 92521, United States

comparative transcriptomics

Presentation Type: Oral Paper
Number: CGT1001
Abstract ID:291
Candidate for Awards:Margaret Menzel Award

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