UCSB researches gene critical to floral nectar spurs
Biologists discovered a new gene that will lead them to new insights on evolution.
This specific discovery deals with evolution in plants: floral nectar spurs. These small tubes increase the distance between the floral reward and the reproductive parts of the flower, leading to greater biodiversity.
Biologists believe this is a “key innovation” in causing a greater number of species to evolve.
Using a combination of genetic mapping, gene expression analyses and functional assays, UCSB professor Scott Hodges and his research associate, Evangeline Ballerini, along with their co-authors, identified a gene critical to the development of these nectar spurs.
This is among the first key innovations for which a critical development gene has been identified, something that will help scientists understand how organisms achieve different shapes and how those shapes evolve.
“We really want to understand how form is controlled and how that’s achieved,” Dr. Hodges told the News-Press. “This is one example of a really striking change in shape, so understanding how that gene works will tell us a lot about how morphology is achieved in general.”
Dr. Hodges’s areas of research include botany, ecology, evolution, evolutionary ecology, evolutionary genetics, macroevolution and organismal biology. The goal of his research is to explain the genetic basis of adaptation and speciation.
“There are a number of morphological traits in particular that scientists have associated with increases in biodiversity,” he said. “What we wanted to know was more about how they evolved. How do you go from not having that key innovation to having it? What kinds of things are involved?”
The researchers named the gene POPOVICH, after Gregg Popovich, the head coach of the San Antonio Spurs basketball team.
“Before, we had no idea about this kind of developmental process. Once we have one gene, that gene is a master regulator. It’s a gene that controls whether other genes are turned on or off,” Dr. Hodges said. “Gregg Popovich oversees the team, and that’s kind of what this gene does. It controls what a whole bunch of different players are doing in the genome.”
He compared the nectar spurs to wings, in that each group of animals that evolved them has spun off into many different species. However, he said wings are too challenging to study because of how old they are.
“Wings evolved so long ago that it’s hard to find specific genes that were critical for evolution,” Dr. Hodges said.
However, nectar spurs are a defining feature of the columbine genus Aquilegia, and that lineage has experienced a “relatively recent and rapid radiation” of five to seven million years. Dr. Hodges said this means scientists can do a lot of genetics on them.
“What we’d really like to know is how plants achieve making different shapes,” Dr. Hodges said. “We may want to breed plants that do a certain thing or make a certain shape. It’s basic science. We want to know how the world works.”
Dr. Hodges and his team’s study can be found in the Proceedings of the National Academy of Sciences, which was first published Aug. 26.