TY - JOUR
T1 - To B or not to B a flower
T2 - The role of DEFICIENS and GLOBOSA orthologs in the evolution of the angiosperms
AU - Zahn, Laura M.
AU - Leebens-Mack, J.
AU - DePamphilis, C. W.
AU - Ma, H.
AU - Theissen, G.
N1 - Funding Information:
The authors thank Shozo Yokoyama for the opportunity to present this review in conjunction with the overview of the Genomes and Evolution meeting at Pennsylvania State University, June 2004. We thank Sangtae Kim for providing a preprint of his B-function phylogeny paper; Robert Schmidt for providing a preprint of his maize B-class function paper; Hongzhi Kong and Yi Hu for allowing us to cite their expression work on Nuphar; Sangtae Kim, Douglas Soltis, and Pamela Soltis for allowing us to cite their work on Amborella, Nuphar, and Illicium; and Victor Albert, Pamela Soltis, and PSU members of the Floral Genome Project for constructive comments and discussion of the manuscript. This work was funded by a National Science Foundation Plant Genome Grant for the Floral Genome Project DBI-0115684. This paper is based on a presentation given at the symposium entitled ‘‘Genomes and Evolution 2004,’’ cosponsored by the American Genetic Association and the International Society of Molecular Biology and Evolution, at the Pennsylvania State University, State College, PA, USA, June 17–20, 2004.
PY - 2005/5
Y1 - 2005/5
N2 - DEFICIENS (DEF) and GLOBOSA (GLO) function in petal and stamen organ identity in Antirrhinum and are orthologs of APETALA3 and PISTILLATA in Arabidopsis. These genes are known as B-function genes for their role in the ABC genetic model of floral organ identity. Phylogenetic analyses show that DEF and GLO are closely related paralogs, having originated from a gene duplication event after the separation of the lineages leading to the extant gymnosperms and the extant angiosperms. Several additional gene duplications followed, providing multiple potential opportunities for functional divergence. In most angiosperms studied to date, genes in the DEF/GLO MADS-box subfamily are expressed in the petals and stamens during flower development. However, in some angiosperms, the expression of DEF and GLO orthologs are occasionally observed in the first and fourth whorls of flowers or in nonfloral organs, where their function is unknown. In this article we review what is known about function, phylogeny, and expression in the DEF/GLO subfamily to examine their evolution in the angiosperms. Our analyses demonstrate that although the primary role of the DEF/GLO subfamily appears to be in specifying the stamens and inner perianth, several examples of potential sub- and neofunctionalization are observed.
AB - DEFICIENS (DEF) and GLOBOSA (GLO) function in petal and stamen organ identity in Antirrhinum and are orthologs of APETALA3 and PISTILLATA in Arabidopsis. These genes are known as B-function genes for their role in the ABC genetic model of floral organ identity. Phylogenetic analyses show that DEF and GLO are closely related paralogs, having originated from a gene duplication event after the separation of the lineages leading to the extant gymnosperms and the extant angiosperms. Several additional gene duplications followed, providing multiple potential opportunities for functional divergence. In most angiosperms studied to date, genes in the DEF/GLO MADS-box subfamily are expressed in the petals and stamens during flower development. However, in some angiosperms, the expression of DEF and GLO orthologs are occasionally observed in the first and fourth whorls of flowers or in nonfloral organs, where their function is unknown. In this article we review what is known about function, phylogeny, and expression in the DEF/GLO subfamily to examine their evolution in the angiosperms. Our analyses demonstrate that although the primary role of the DEF/GLO subfamily appears to be in specifying the stamens and inner perianth, several examples of potential sub- and neofunctionalization are observed.
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U2 - 10.1093/jhered/esi033
DO - 10.1093/jhered/esi033
M3 - Article
C2 - 15695551
AN - SCOPUS:15944363823
SN - 0022-1503
VL - 96
SP - 225
EP - 240
JO - Journal of Heredity
JF - Journal of Heredity
IS - 3
ER -