The asymmetric shape of the Antirrhinum corolla is determined by genes acting differentially along the dorsoventral axis of the flower. Genes so far identified determine asymmetry by acting in dorsal regions. We describe a gene, divaricata, which in contrast to previously identified genes acts in ventral regions of the flower. We show by the analysis of mutant combinations that the divaricata gene is negatively regulated by the dorsal genes cycloidea and dichotoma. In addition, we show by the analysis of chromosomal duplications that the divaricata gene acts in a dosage-dependent manner, suggesting that the level of its product is critical for determining ventral identities.

Almeida
J.
,
Carpenter
R.
,
Robbins
T. P.
,
Martin
C.
,
Coen
E. S.
(
1989
)
Genetic interactions underlying flower color patterns in Antirrhinum majus.
Genes Dev
3
,
1758
1767
Carpenter
R.
,
Coen
E. S.
(
1990
)
Floral homeotic mutations produced by transposon-mutagenesis in Antirrhinum majus.
Genes Dev
4
,
1483
1493
Carpenter
R.
,
Martin
C.
,
Coen
E. S.
(
1987
)
Comparison of genetic behaviour of the transposable elemnt Tam3 at two unlinked pigment loci in Antirrhinum majus.
Mol. Gen. Genet
207
,
82
89
Coen
E. S.
,
Carpenter
R.
,
Martin
C.
(
1986
)
Transposable elements generate novel spatial patterns of gene expression in Antirrhinum majus.
Cell
47
,
285
296
Coen
E. S.
,
Meyerowitz
E. M.
(
1991
)
The war of the whorls: genetic interactions controlling flower development.
Nature
353
,
31
36
Coen
E. S.
,
Romero
J. M.
,
Doyle
S.
,
Elliot
R.
,
Murphy
G.
,
Carpenter
R.
(
1990
)
floricaula: a homeotic gene required for flower development in Antirrhinum majus.
Cell
63
,
1331
1322
Driever
W.
,
Nusslein-Volhard
C.
(
1988
)
The bicoid protein determines position in the embryo in a concentration-dependent manner.
Cell
54
,
95
104
Luo
D.
,
Carpenter
R.
,
Vincent
C.
,
Copsey
L.
,
Coen
E. S.
(
1996
)
Origin of floral asymmetry in Antirrhinum.
Nature
383
,
794
799
Martin
C.
,
Carpenter
R.
,
Sommer
H.
,
Saedler
H.
,
Coen
E. S.
(
1985
)
Molecular analysis of instability in flower pigmentation of Antirrhinum majus, following isolation of the pallida locus by transposon tagging.
EMBO J
4
,
1625
1630
Nusslein-Volhard
C.
,
Wieschaus
E.
(
1980
)
Mutations affecting segment number and polarity in Drosophila.
Nature
287
,
795
801
Robbins
T. P.
,
Carpenter
R.
,
Coen
E. S.
(
1989
)
A chromosome rearrangement suggests that donnor and recipient sites are associated during Tam3 transposition in Antirrhinum majus.
EMBO J
8
,
5
13
Schwarz-Sommer
Z.
,
Huijser
P.
,
Nacken
W.
,
Saedler
H.
,
Sommer
H.
(
1990
)
Genetic control of flower development by homeotic genes in Antirrhinum majus.
Science
250
,
931
936
This content is only available via PDF.