Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Vlad, Daniela [1], Kierzkowski, Daniel [2], Rast, Madlen I. [2], Vuolo, Francesco [2], Ioio, Raffaele Dello [2], Galinha, Carla [3], Gan, Xiangchao [2], Hajheidari, Mohsen [2], Hay, Angela [2], Smith, Richard [2], Huijser, Peter [2], Bailey, C. Donovan [4], Tsiantis, Miltos [2].

Gene family evolution among Brassicaceae HD-ZIP I genes and the origin of REDUCED COMPLEXITY (RCO).

The REDUCED COMPLEXITY gene (RCO) is a recently described member of the HD-ZIP I gene family that is sufficient to explain macromorphological leaf shape variation in members of the Brassicaceae.  Specifically, RCO expression and function (repression of growth) in leaf margins leads to increased dissection of leaves in Cardamine hirsuta, while the simple entire leaves of Arabidopsis thaliana develop in a genomic context that lacks RCO.  Here we investigate patterns of gene family evolution in the relevant HD-ZIP I family members, LMI1 and RCO, to better understand the evolution these genes and the origin of the associated phenotypes.  Using phylogenetic analysis of cDNA and gDNA sequences, we illustrate that RCO is derived from an LMI1 duplication that likely occurred between the divergence of Aeithonema from all other Brassicaceae and the divergence of the lineages leading to Arabidopsis and Brassica.  RCO further duplicated along the stem lineage leading to Lineage I Brassiceae (Cardamine, Capsella, Arabidopsis and relatives) with just one of the two copies of RCO apparently retaining function.  Of the Brassicaceae lineages investigated to date, those containing and expressing a copy of RCO show increased leaf shape complexity, while A. thaliana, which has secondarily lost RCO, has simple entire leaves.  Thus the complex pattern of gene family evolution observed here, including duplication, divergence in pattern of expression, and secondary loss, is a critical element of species-specific leaf shape variation among Brassicaceae.

1 - University of Oxford, Department of Plant Sciences, Oxford, OX4 3RB, UK
2 - Max Planck Institute For Plant Breeding Research, Department of Comparative and Developmental Genomics, Carl-von-Linne-Weg 10, 50829, Germany
3 - University of Oxford, Department of Plant Sciences, Oxford, OX1 3RB, UK
4 - New Mexico State University, PO Box 30001 MSC 3AF, Las Cruces, NM, 88003, USA

Keywords:
RCO.

Presentation Type: Oral Paper:Papers for Topics
Session: 46
Location: Payette/Boise Centre
Date: Wednesday, July 30th, 2014
Time: 4:00 PM
Number: 46002
Abstract ID:786
Candidate for Awards:None