Most plants are hermaphrodites and have both male and female reproductive parts. Oaks, some orchids, potted spider plants in your office – they can all be recreated without another sex member nearby.
“If you're an organism that you can't run around and find a companion, that makes sense,” says Deborah Charlesworth, a population geneticist at the University of Edinburgh, who has been studying plant reproductive strategies for decades. I said.
However, some plants take a different approach. They have evolved sex chromosomes, bits of DNA that make individual plants either male or female. In the club, the females produce stinky fruits are creatures like raw bingo that men smell. Or think of asparagus, where women produce redder fruits and thinner stems than men.
Some of these species are still unknown. Their sex chromosomes are strangely abnormal. For example, small white campion plants pack Y chromosomes larger than the entire genome of a fig fish or the entire fruit fry genome. In Thursday's journal Science, collaborative researchers, including Dr. Charlesworth, will be releasing the complete sequence of White Campion's somatic Y chromosomes, giving you a closer look at its contents and evolutionary history.
DNA sequencing has become common these days. However, in the 1990s, when high-speed sequencing technology was new and promoted a revolution in biology, scientists were unable to effectively use Y chromosomes in plants, and a biologist at the University of Claude Bernard Dorillon in France. said Gabriel Murray, a senior author biologist. New paper.
This tends to repeat many of the same sequences, as the techniques used for the remaining sequencing of the genome do not work well on the Y chromosome. Slicing Y chromosomes, sequence fragments, and trying to piece them together like a puzzle – works very well with other genomes – brings so many identical pieces, so assembling a large image It is impossible.
However, over the past decade, the arrival of a different form of sequence has made it possible to retry.
No slices or obstacles are required. It allows you to decipher long, intact stretches of chromosomes. In a new paper, Dr. Murray and his colleagues used the technique with a white campion Y. They then sequenced sex chromosomes in male plants, which were found to show genes identified as mutations that play different roles in making them male. Some genes suppressed female traits. Others encouraged males, affecting processes such as flower development and pollen production.
The findings may explain why the Y chromosome of white campions is so mammoth. Conserving these genes and maintaining other genes like them may have been prioritized over keeping chromosomes compact, Dr. Charlesworth said. Much of the Y bulk is an endless copy-and-paste fest, consisting of fragments of DNA that tend to replicate themselves.
In many organisms, the X and Y chromosomes may abandon the extra material during the DNA swapping session. However, Campion thus lost much of its ability to clean up most of its sex chromosomes. This is probably because it could put the integrity of these genes at risk. Over time, the idea will accumulate more and more material, leading to an unusually large chromosomal reservoir.
Understanding that plants that develop two genders determine which plants become male or female has an impact beyond scientific curiosity. Many crop plants, including figs, papayas, grapes, and more, fall into that category. Cannabis has a particularly ancient system for determining gender, Dr. Charlesworth pointed out by Charlesworth, two to three times older than White Campion.
Strangely enough, researchers could speculate that there has been some growth in the presence of chromosomes over the past 11 million years. What drove those bursts is still a mystery. They hope that future work and identifying more genes that promote sex differences will light up more about how this Y chromosome has become huge.
