VERBOOM, G. ANTHONY*, SIMON T. MALCOMBER, ANDREW N. DOUST, and ELIZABETH A. KELLOGG. Department of Biology, University of Missouri, 8001 Natural Bridge Road, Saint Louis, MO 63121, U.S.A.. - Sequence variation in the KNOTTED1 gene family across the grass family (Poaceae): implications for protein primary and secondary structure.
KNOTTED-like homeobox genes are thought to be critical in plant
morphogenesis, apparently being involved in meristem initiation and/
or maintenance. Sequence variation in this potentially important gene
family is, however, poorly documented. In grasses, for example,
published knowledge of sequence variation among Kn1 homologues
is based on data from as few as three species (barley, maize and
rice). In order to gain a broader understanding of variation among
Kn1 homologues in grasses, we designed primers to amplify an
800bp portion of this gene family across a phylogenetically-diverse
array of grasses. This sequence excludes the homeodomain and spans two
introns that have a total length of about 300bp. In this paper we
compare levels of sequence variation between coding and non-coding
regions and evaluate how changes in the former influence protein
primary and secondary structure. Finally, using the GPWG phylogeny of
the grass family as a baseline, we use character optimization methods
to identify in which lineages major levels of change have taken
place.
Key words: homeobox genes, KNOTTED, Poaceae