Modification of the ABC Program and the Evolution of Floral Novelty

Harvard University, Cambridge MA

Investigators

Abstract

The variety of life-from apples to zebras-is beautiful, engaging and excites the imagination. The question of how different forms arise is one of the most fascinating and important in all of biology. The flowering plants offer a wonderful opportunity to investigate the genetic basis evolutionary novelty, especially in the context of unique forms of floral organs. Most flowers display a standard set of organs-sepals, petals, stamens, and carpels-but some have evolved fifth organ types. This project uses the new model system Aquilegia (columbine) to understand the genetic basis of novel floral organ identity and elaboration. In columbines, standard floral organs may develop fantastic new features, such as petal nectar spurs that vary in length from a few mm to over 12 cm. The project builds on previous studies to understand i) how gene duplication has contributed to the evolution of a fifth, distinct form of floral organ, the staminodium; ii) what other genetic changes contributed to the evolution of the staminodium; and iii) how development of Aquilegia's petal nectar spurs is controlled from a hormonal and genetic standpoint. Training our next generation of scientists requires getting students excited about the scientific process and familiarizing them with the real day to day practice of science. Genetic annotation of the recently sequenced Aquilegia genome will be used as the basis for a lecture/lab module in the Crimson Summer Academy, a summer program at Harvard for academically talented high school students from financially disadvantaged backgrounds. This program will engage students with a wide range of topics including gene and genome organization, gene evolution and the process of writing a publishable scientific article.