Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Zhang, Jingbo [1], Zhang, Wenheng [2].

Gene duplication and divergent spatial expression of CYCLOIDEA2-like paralogs in Solanaceae.

The Solanaceae family exhibits a wide range of floral symmetry, with floral actinomorphy dominating derived lineages such as Solanum and strong floral zygomorphy found in basal clades such as Schizanthus. The basal grade of the family possesses different degrees of floral zygomorphy. CYCLOIDEA2 (CYC2)-like genes have been independently recruited to control the development of floral zygomorphy in core eudicots. Here, we investigate the evolution and expression of CYC2-like genes in Solanaceae. We have cloned CYC2-like genes from all major lineages of Solanaceae and found two major copies, called CYC2-I and CYC2-II. The gene genealogy indicates that gene duplication gave rise to CYC2-I and CYC2-II preceding the diversification of the family. The expression of the CYC2 paralogs was examined in tomato (Solanum lycopersicum) and Schizanthus grahamii. The results indicate that CYC2-I is expressed mainly in the axillary branches of tomato and at barely detectable levels in developing flowers. The expression of CYC2-II is continuous throughout the floral development in tomato and S. grahamii. Our preliminary expression data indicates that the functions of the two paralogs are greatly divergent, with CYC2-II evidently involved in floral development. Ongoing in situ and virally induced gene silencing experiments will further characterize the spatial patterns and functions of the CYC2-I and -II genes in Solanaceae.

1 - Chinese Academy of Sciences, Institute of Botany, Xiangshan, Beijing, 100093, China
2 - Virginia Commonwealth University, Department of Biology, 1000 West Cary Street, Life Science Building, Richmond, VA, 23284-2012, USA

Keywords:
cycloidea
floral development
floral symmetry
floral evolution
Phylogeny
functional divergence of gene duplicates
Solanaceae.

Presentation Type: Oral Paper:Papers for Topics
Session: 46
Location: Payette/Boise Centre
Date: Wednesday, July 30th, 2014
Time: 4:45 PM
Number: 46005
Abstract ID:526
Candidate for Awards:Katherine Esau Award