Journal article

Publication year: 2002

Pages: 942-950

Journal: Molecular Genetics and Genomics

Volume number: 266

Issue number: 6

ISSN: 1617-4615

eISSN: 1617-4623

DOI Link: https://doi.org/10.1007/s00438-001-0615-8

Publisher: Springer

Abstract: 
Class B floral homeotic genes specify the identity of petals and stamens
during the development of angiosperm flowers. Recently, putative
orthologs of these genes have been identified in different gymnosperms.
Together, these genes constitute a clade, termed B genes. Here we report
that diverse seed plants also contain members of a hitherto unknown
sister clade of the B genes, termed B_sister (B_s) genes. We have isolated members of the B_s clade from the gymnosperm Gnetum gnemon, the monocotyledonous angiosperm Zea mays and the eudicots Arabidopsis thaliana and Antirrhinum majus. In addition, MADS-box genes from the basal angiosperm Asarum europaeum and the eudicot Petunia hybrida were identified as B_s genes. Comprehensive expression studies revealed that B_s
genes are mainly transcribed in female reproductive organs (ovules and
carpel walls). This is in clear contrast to the B genes, which are
predominantly expressed in male reproductive organs (and in angiosperm
petals). Our data suggest that the B_s genes played an
important role during the evolution of the reproductive structures in
seed plants. The establishment of distinct B and B_s gene
lineages after duplication of an ancestral gene may have accompanied the
evolution of male microsporophylls and female megasporophylls 400–300
million years ago. During flower evolution, expression of B_s
genes diversified, but the focus of expression remained in female
reproductive organs. Our findings imply that a clade of highly conserved
close relatives of class B floral homeotic genes has been completely
overlooked until recently and awaits further evaluation of its
developmental and evolutionary importance.

Harvard Citation style: Becker, A., Kaufmann, K., Freialdenhoven, A., Vincent, C., Li, M., Saedler, H., et al. (2002) A novel MADS-box gene subfamily with a sister-group relationship to class B floral homeotic genes, Molecular Genetics and Genomics, 266(6), pp. 942-950. https://doi.org/10.1007/s00438-001-0615-8

APA Citation style: Becker, A., Kaufmann, K., Freialdenhoven, A., Vincent, C., Li, M., Saedler, H., & Theißen, G. (2002). A novel MADS-box gene subfamily with a sister-group relationship to class B floral homeotic genes. Molecular Genetics and Genomics. 266(6), 942-950. https://doi.org/10.1007/s00438-001-0615-8