What's Hiding in This Flower's Giant Y Chromosome

A recent article by Veronique Greenwood in The New York Times discusses how scientists have finally sequenced the Y chromosome of the white campion, a flower with a massive Y chromosome, even bigger than the entire genome of some organisms like puffer fish and fruit flies. Unlike most plants, which are hermaphrodites, white campion, on the other hand, has distinctive male and female sexes, thanks to sex chromosomes. Researchers have found that the Y chromosome is packed with genes controlling male traits and a lot of repetitive DNA that has been copying itself for millions of years. Scientists also discovered that, unlike in many other organisms where X and Y chromosomes swap DNA to remove excess material, the white campion lost this ability long ago, perhaps because swapping could have endangered the integrity of these genes, leading to its unusually massive Y chromosome.

         

            This discovery isn't just about curiosity, but understanding how sex chromosomes evolve could have a real-world impact, as many crops, like papaya and cannabis, rely on a similar system, so this research could help with breeding and agriculture. It could also help in understanding how sex-determining genes remain stable, or why some Y chromosomes remain stable, while some like this keep expanding.