Abstract Detail

Evolutionary Developmental Biology (Evo-Devo)

Kramer, Elena [1], Min, Ya [2], Edwards, Molly [3], Meaders, Claire [4], Ballerini, Evangelline [5], Hodges, Scott [5].

Exploring the genetic basis of floral novelty in Aquilegia.

The lower eudicot model system Aquilegia possesses several novel morphological features that have the potential to shed light on the evolution of novelty, particularly in the context of complex organ form. We have been studying two key features of the Aquilegia flower: the three-dimensional petal nectar spur and a fifth floral organ type, the staminodium. In the case of the petal spur, we have found that Aquilegia petal spurs initiate due to a localized region of cell division in which cell wall formation is radially organized around the presumptive nectary. This lays the ground pattern of the spur, which is then realized through rapid, anisotropic cell elongation that is the major determinant of spur length and curvature. Diversification of spur morphology has involved multiple factors, including heterochronic shifts that generate much longer, narrower cells; differences in cell numbers around the radial axis of the spur; and independent control of cell elongation on different surfaces of the spur, which generates curvature. We are now combining transcriptomics, candidate gene approaches, and QTL mapping to explore the genetic architecture of spur development and understand its evolution. In the case of the staminodium, we have previously discovered that this novel organ identity is determined via the combinatorial activity of paralogs of the genes that normally confer stamen identity, such that the stamens and staminodia now have distinct genetic codes via sub- and neofunctionalization. We are further exploring the developmental and morphological oddities of the staminodia, what their ecological function may be, and how their developmental program diverges from that of stamens.

1 - Harvard Univ., OEB, 16 Divinity Avenue, Cambridge, MA, 02138, United States
2 - Kramer Lab Biolabs Room 1119, 16 Divinity Ave., Cambridge, MA, 02138, United States
3 - Harvard University, Biolabs Room 1119, 16 Divinity Ave, Cambridge, MA, 02138, United States
4 - Havard University, Organismic and Evolutionary Biology, 16 Divinity Ave., Cambridge, MA, 02138, USA
5 - University of CA, Santa Barbara, Ecology, Evolution and Marine Biology, Santa Barbara, CA, USA

Keywords:
floral evodevo
Aquilegia
nectar spur
staminode.

Presentation Type: Oral Paper
Session: 20, Evolutionary Developmental Biology (Evo-Devo) I
Location: 113/Mayo Civic Center
Date: Tuesday, July 24th, 2018
Time: 9:30 AM
Number: 20007
Abstract ID:223
Candidate for Awards:None