Researchers have solved the century-old mystery of a supergene that causes efficient cross-pollination in flowers. The results reveal 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.

Since the 1500s, botanists and gardeners have known that some plant species have two forms of flowers that differ reciprocally in the length of their male and female sexual organs. Charles Darwin first proposed that such distylous flowers promoted efficient cross-pollination by insect pollinators. Early geneticists showed that the two forms of flowers were controlled by a single chromosomal region that likely harbored a cluster of genes, a supergene. Until recently, however, this supergene had never been sequenced. [1]

Figure 1. Scientists Solve Century-Old Supergene Mystery

Figure 1 shows the researchers were surprised to find that the length of the supergene that was responsible for the differences in the length of male and female sexual organs fluctuated itself. To be more specific, the recessive form of the supergene lacked approximately 260,000 base pairs of DNA whereas the dominant form of the supergene had these base pairs. The stretch of DNA with 260,000 base pairs contained numerous genes, some of which were likely responsible for length variation in sexual organs. [2]

Surprisingly, the researchers found that the supergene answerable for differing lengths of female and male sexual organs itself assorted in size. Particularly, the dominant type of the supergene contained about 260,000 base pairs of DNA that had been lacking from the recessive type. [3]

”These results were really surprising to us, because a similar genetic makeup of the supergene that governs distyly has previously been identified in another system, primroses, where it evolved completely independently,” said Tanja Slotte, senior author of the study and Professor in Ecological Genomics at Stockholm University.

These discoveries provide new insights into the remarkable power of evolution to find convergent solutions to widespread adaptive challenges such as the need for flowering plants to be cross-pollinated. [4]

References:

1. https://news.knowledia.com/ZA/en/articles/scientists-solve-century-old-supergene-mystery-02791c238644cb4d24a257565c7eb19ae870d56b
2. https://neutrino-science.com/a-century-old-supergene-mystery-is-solved-by-scientists/
3. https://lightaholictech.blogspot.com/2022/09/scientists-solve-century-old-supergene.html
4. https://scitechdaily.com/scientists-solve-century-old-supergene-mystery/

Cite this article:

Thanusri swetha J (2022), Scientists Solve Century-Old Supergene Mystery, AnaTechMaz, pp.108