Systematics Section / ASPT
Budke, Jessica M. , Wickett, Norman J. , Goffinet, Bernard .
Multiple losses of the cysA gene from the chloroplast genome of liverworts (Marchantiophyta).
The cysA gene is located in the chloroplast genome and encodes a protein that is a subunit of the sulfate import ABC transporter complex (cysAWTP). Since their endosymbiotic origin, chloroplast genomes have undergone dramatic reductions. Although the size of the genome is relatively stable among land plants, further gene losses are reported from various embryophytes. CysA is lacking in most land plants except the liverwort Marchantia polymorpha. We surveyed representatives of the five major clades of liverworts to assess the phylogenetic significance of the cysA loss from the chloroplast genome during the diversification of these lineages. Our current results indicate that this gene is present with an open reading frame in all sampled members of the complex thalloid liverworts (Marchantiopsida) and that multiple independent losses have occurred in the leafy liverworts and simple thalloid liverworts (Jungermanniopsida). Losses are characterized by large deletions that lead the complete loss of the gene or an extremely truncated reading frame. Whether the gene is completely lacking from the chloroplast genome, relocated within this genome or transferred to the nucleus is currently being tested.
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1 - University of Connecticut, Ecology & Evolutionary Biology, 75 North Eagleville Road, U-3043, Storrs, Connecticut, 062693043, USA
Presentation Type: Oral Paper:Papers for Sections
Location: Boulevard C/Hilton
Date: Wednesday, July 11th, 2007
Time: 8:00 AM