Compiled ｜ Wang Fang
According to a study published in Communications Biology on January 11th, scientists have found some of the earliest known cases of sex chromosome disorders in five ancient humans."It's fascinating to think that these people existed throughout human history and were part of society," said Kyriaki Anastasiadou, the lead author of the study and a researcher at the Francis Crick Institute in the UK.Individuals with extra or missing chromosomes often have differences in appearance and behavior compared to others. By identifying these individuals with genetic syndromes, researchers can shed light on how past societies viewed and treated people with differences.Using ancient DNA sequencing, researchers had previously identified two individuals from ancient times with abnormal chromosome numbers, including an infant with Down syndrome. He lived approximately 5,000 years ago, and this syndrome is caused by an extra copy of chromosome 21.Now, Anastasiadou and her colleagues have discovered the first known prehistoric human with Turner syndrome. This person lived in Somerset County, England, during the Iron Age about 2,500 years ago. Turner syndrome occurs in females and is characterized by having only one complete copy of the X chromosome instead of the usual two found in females. Individuals with Turner syndrome often have short stature and infertility issues.The other individuals identified with sex chromosome disorders were all males. This includes the earliest known case of a person with an extra Y chromosome, known as Jacob syndrome, which is associated with above-average height. This man lived in the early Middle Ages approximately 1,100 years ago.The research team also found three ancient males from different time periods who had an extra X chromosome in addition to the X and Y chromosomes. This condition is known as Klinefelter syndrome and is associated with above-average height, wider hips, and larger breasts.The researchers analyzed DNA samples extracted from teeth, skulls, jaws, and ear bones. For each individual, they used a computational tool to calculate the number of DNA fragments from the X and Y chromosomes and compared it to the number of fragments from non-sex chromosomes. Based on this, they inferred the presence and ratio of X and Y chromosomes for each person. The team has made this tool available online."There is no evidence that these people were treated differently from ordinary individuals. At first glance, their cause of death and burial practices seem to be no different," said Anastasiadou."This is a major breakthrough that provides a window into how ancient societies viewed and dealt with people who had differences," said Bettina Arnold, an anthropologist at the University of Wisconsin-Milwaukee in the United States. She believes that this approach can reveal the meaning of being human."The more research we do like this, the more we can explore how past societies perceived and understood sex and gender, as well as how people in the past interpreted disabilities caused by certain genetic syndromes," said Ulla Moilanen, an archaeologist at the University of Turku in Finland.Related paper information:
https://doi.org/10.1038/s42003-023-05642-z
China Science News (2024-01-17, Second Edition, International, originally titled "Ancient DNA reveals earliest cases of sex chromosome disorders")Editor | Ji HongmeiType Setting | Guo GangPlease scan the QR code below for recognition in 3 seconds
