Two related flower-expressed gene copies
belonging to the SF21 (sunflower-21) gene family have
been isolated from Senecio squalidus (Oxford Ragwort,
Asteraceae). These gene copies are differentially expressed
in pollen and pistil tissues; ORSF21B (Oxford Ragwort
SF21B) is expressed exclusively in mature pollen, whereas
ORSF21A (Oxford Ragwort SF21A) is expressed in the
transmitting tissue of the style, where it is developmentally
regulated. Despite differences in expression, the coding
regions of ORSF21A and ORSF21B are highly similar.
Amino acid sequence alignments of SF21 genes from a
number of angiosperm species indicate that this gene
family is conserved in flowering plants and may play an
important role in reproductive processes in a wide range of
taxa. Phylogenetic analysis of SF21 nucleotide sequence
alignments supports this theory, and indicates a complicated
history of evolution of this gene family in
Communicated by Hugh Dickinson.
Electronic supplementary material The online version of this
article (doi:10.1007/s00497-010-0137-9) contains supplementary
material, which is available to authorized users.
A. M. Allen S. J. Hiscock (&)
School of Biological Sciences, University of Bristol,
Woodland Road, Bristol BS8 1UG, UK
e-mail: simon.hiscock@bristol.ac.uk
C. Lexer
Royal Botanic Gardens, Kew, Richmond,
Surrey TW9 3DS, UK
Present Address:
C. Lexer
Department of Biology, Unit of Ecology and Evolution,
University of Fribourg, Chemin du Muse
´
e 10,
1700 Fribourg, Switzerland
angiosperms. The putative roles of SF21 genes in reproduction
and pollen–pistil interactions are discussed.