Abstract Detail

Molecular Ecology and Evolution

Hawkins, Angela K. [1], Pepper, Alan E.  [1].

Evolutionary insights from transcriptome comparisons of the serpentine endemic Caulanthus amplexicaulis var. barbarae and its non-serpentine sister species, C. amplexicaulis var. amplexicaulis.

Advances in next generation sequencing technology and bioinformatics have allowed researchers to examine the genetic basis of adaptation using organisms that are traditionally considered ‘non-model’ species. Caulanthus amplexicaulis var. barbarae (J. Howell) Munz (CAB) is a wild relative of Arabidopsis thaliana (L.) Heynh and is endemic to serpentine outcrops. Its sister species, C. amplexicaulis var. amplexicaulis S. Watson (CAA), is predominately found on granite soils, and in reciprocal growth experiments has demonstrated 100% mortality when grown in serpentine-like conditions. Serpentine outcrops are derived from ultramafic rock and usually have extremely low levels of essential plant nutrients (e.g. N, P, Ca), very high to toxic levels of heavy metals (e.g. Ni), and very poor water availability and retention. Distribution of serpentine outcrops is ubiquitous but patchy, and interestingly are often home to many endemic plant species. Understanding the adaptive mechanisms that allow survival in such harsh edaphic environments has long been an interest of many plant biologists. Using both ecologically distinct parents, we constructed and assembled normalized transcriptome libraries, providing reference sequences for future RNA-seq experiments and molecular evidence for functional annotation of the CAB whole-genome sequencing project (in progress with the DOE Joint Genome Institute). Here we describe the assignment of gene ontologies, and the identification of orthologous pairs (or groups) of genes in CAA and CAB. We also examined the levels and pattern of genetic variation at the nucleotide and protein levels, and searched for evidence of purifying and divergent natural selection.

1 - Texas A&M University, Department of Biology, Texas A&M University, 3258 TAMUS, College Station, Texas, 77843-3258, USA

Keywords:
Brassicaceae
Serpentine soils
Caulanthus.

Presentation Type: Oral Paper:Papers for Topics
Session: 28
Location: Firs South/Boise Centre
Date: Tuesday, July 29th, 2014
Time: 2:15 PM
Number: 28004
Abstract ID:631
Candidate for Awards:Margaret Menzel Award