A scientist from our Department of Biosciences along with colleagues in Stockholm University, Uppsala University, University of Grenada and University of Seville, have solved the mystery of the supergene that causes efficient cross-pollination in flowers.
Their study results show that sequence length variation at the DNA level is important for the evolution of two forms of flowers that differ in the length of their sexual organs.
Analysing the supergene
The researchers studied a Linum flaxseed species, first described by Darwin, where two forms of flowers differ reciprocally in the length of their male and female sexual organs.
They used modern DNA sequencing methods to identify the supergene.
Surprisingly, they found that the supergene responsible for differing lengths of male and female sexual organs varied in length itself.
Specifically, the dominant form of the supergene contained about 260,000 base pairs of DNA that were missing from the recessive form. The 260,000 base pair stretch of DNA harboured several genes likely to cause length variation in sexual organs.
Interestingly, the same solution of supergene sequence length differences had recently been found in an independently evolved cross-pollination system in primroses.
New insights
The research findings shed new lights into the exceptional power of evolution to find convergent solutions to widespread adaptive challenges such as the need for flowering plants to be cross-pollinated.
The project has been funded by European Research Council (ERC) under the European Union's Horizon 2020 research and innovation programme.
