Abstract Detail

Seed-free Plants at the Genomic Scale

Grusz, Amanda [1], Schuettpelz, Eric [1].

Consistently inconsistent: Transcriptome data reveal widespread molecular evolutionary rate asymmetry in ferns.

The plastid genome has, until recently, been the primary molecular resource for evolutionary studies in ferns. Now transcriptomics in non-model plant systems has progressed to a point where the examination of nuclear genome-wide patterns in understudied groups is also possible. Here, we utilize transcriptome data in the first genome-wide comparative study of molecular evolutionary rate in ferns. We focus on the ecologically diverse family Pteridaceae, which comprises about 10% of extant fern diversity and includes the enigmatic vittarioid ferns—an exclusively epiphytic, tropical lineage known for dramatically reduced morphologies and radically elongated phylogenetic branch lengths. Using 2091 loci sampled from 12 species spanning the family, we ask whether previously documented heterogeneity in plastid substitution rate is reflected in their nuclear genomes. We then inquire whether variation in evolutionary rate is being shaped by genes belonging to specific functional categories and test for differential patterns of selection. Our results reinforce recently reviewed mechanisms hypothesized to shape molecular evolutionary rates in vittarioid ferns and provide novel insight into substitution rate variation both within and among the nuclear genomes of ferns.

1 - Smithsonian Institution, Department of Botany, P.O. Box 37012, Washington, DC, 20013

Keywords:
Adiantum
GO enrichment
Molecular evolution
Substitution rates
vittarioid.

Presentation Type: Colloquium Presentations
Session: C4, Seed Free Plants at the Genomic Scale
Location: Chatham Ballroom - C/Savannah International Trade and Convention Center
Date: Wednesday, August 3rd, 2016
Time: 4:15 PM
Number: C4012
Abstract ID:726
Candidate for Awards:None