Abstract Detail

Genetics Section

Coate, Jeremy [1], Song, Michael [2], Bombarely, Aureliano [3], Doyle, Jeff J. [4].

Cross-species and cross-ploidy level transcriptomic data support important roles for selection on gene dosage in shaping gene networks.

Selection on relative gene dosage (to maintain proper stoichiometry among interacting proteins) and selection on absolute gene dosage (to increase protein abundance), have been proposed to explain recurrent patterns of duplicate gene retention and loss. In order for relative or absolute gene dosage to be visible to natural selection, there must necessarily be a tight correlation between gene copy number and gene expression level (transcript abundance), but this has rarely been examined. Additionally, in the few cases where the relationship between gene copy number and transcript abundance has been quantified, the two have often been decoupled (i.e., gene dosage responses are highly variable). We used RNA-Seq data for seven Glycine species (three recently formed allotetraploids and their four diploid progenitors) to determine if gene dosage responses at the level of transcription are consistent with selection on relative and/or absolute gene dosage. We found compelling expression-level evidence in support of selection on relative gene dosage. Putatively dosage sensitive gene networks (metabolic pathways and gene ontologies) exhibited reduced expression variance across species, as well as more coordinated expression responses to whole genome duplication (WGD), than putatively dosage-insensitive networks. In contrast, we observed only weak support for selection on absolute dosage. We conclude that selection on relative dosage has played an important role in shaping gene networks in Glycine, whereas selection on absolute dosage has likely played a lesser role.

1 - Reed College, Plant Biology, 3203 SE Woodstock Blvd., Portland, OR, 97202, USA
2 - Reed College, Biology, 3203 SE Woodstock Blvd, Portland, OR, 97202, United States
3 - Virginia Tech, Horticulture, Blacksburg, VA, USA
4 - Cornell University, 412 Mann Library Building, Ithaca, NY, 14853-4301, USA

Keywords:
gene duplication
gene expression
gene dosage
Polyploidy.

Presentation Type: Oral Paper:Papers for Sections
Session: 6
Location: Salon 15/16/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 8:15 AM
Number: 6002
Abstract ID:763
Candidate for Awards:Margaret Menzel Award