Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Sengupta, Aniket [1], Hileman, Lena [2].

Of central importance: control of carpel zygomorphy in tribe Antirrhineae by CYCLOIDEA-RADIALIS interaction.

Zygomorphic perianths are an evolutionary novelty that have evolved numerous times among angiosperms. The genetic basis of perianth zygomorphy is best understood in Antirrhinum majus (Antirrhineae, Lamilaes) where the perianth is zygomorphic along the dorso-ventral axis. The dorsal side is defined by the interaction of three genes: CYCLOIDEA, DICHOTOMA, and RADIALIS, wherein RADIALIS is upregulated by the first two. RADIALIS can affect phenotype both cell-autonomously and non-autonomously. Antirrhinum carpels and fruits are also zygomorphic with two morphologically divergent locules on the dorso-ventral axis. However, the locules of a close relative, Linaria vulgaris, are identical in morphology (non-zygomorphic) though its perianth is zygomorphic. We report that in the mutants cycloidea, cycloidea:dichotoma, and radialis in Antirrhinum, the dorsal locule is ventralized, suggesting a conservation of CYCLOIDEA-RADIALIS interaction in defining carpel zygomorphy. Previously published in situ assays and our quantitative polymerase chain reactions could not detect significant levels of CYCLOIDEA or DICHOTOMA mRNA in Antirrhinum carpels or fruits, suggesting that CYCLOIDEA controls early carpel development non-cell autonomously through RADIALIS. We find abundant RADIALIS mRNA in mid-carpels and in fruits, suggesting a cell-autonomous control by RADIALIS in those stages. To further test the role of RADIALIS orthologs in origin of carpel zygomorphy, we will perform comparative analysis of carpel development between Antirrhinum and Linaria. We will first test for expression of RADIALIS orthologs in Linaria carpels, and then by microscopy, determine whether the absence of zygomorphy in Linaria carpel is ab initio, or involves a compensatory cell division/expansion later in development.

1 - University Of Kansas, Ecology And Evolutionary Biology, 8009 Haworth Hall, 1200 Sunnyside Avenue, Lawrence, KS, 66045, United States
2 - University Of Kansas, Ecology And Evolutionary Biology, 1200 Sunnyside Avenue, Lawrence, KS, 66045, United States

Keywords:
fruit symmetry
CYCLOIDEA
RADIALIS
Antirrhinum.

Presentation Type: Oral Paper
Session: 20, Evolutionary Developmental Biology (Evo-Devo) I
Location: 113/Mayo Civic Center
Date: Tuesday, July 24th, 2018
Time: 8:00 AM
Number: 20001
Abstract ID:94
Candidate for Awards:Katherine Esau Award