WASHINGTON, Aug. 23 (Reuters) – Scientists have taken an important step in understanding our genetic blueprint, the human genome, by deciphering the enigmatic Y chromosome present in males. . The findings may guide research on male infertility.
Researchers Wednesday revealed the first complete sequence of the human Y chromosome. The Y chromosome is one of the two sex chromosomes, the other being the X chromosome, and is normally passed from male parents to male offspring. This is the last of the 24 chromosomes (thread-like structures that carry genetic information from cell to cell) in the human genome to be sequenced.
Humans have a pair of sex chromosomes in each cell. With some exceptions, males have one Y and one X chromosome, while females have two X chromosomes.
Genes on the Y chromosome help control important reproductive functions, including sperm production, formally called spermatogenesis, and are also involved in cancer risk and severity. However, this chromosome has a very complicated structure, so it was known to be difficult to decipher.
“I think this is due to new sequencing technologies and computational methods,” said Alan Lee, a staff scientist at the National Human Genome Institute and lead author of the study detailing the findings in the journal. Ta. Nature.
“This finally provides the first complete picture of the Y-chromosome code, a chromosome that was previously missing from the genome map,” said a professor of biomolecular engineering at the University of California, Santa Cruz (UCSC) and a research collaborator. revealed a length of more than 50% of the Author Karen Miga is co-leader of the Telomere vs. Telomere Consortium supporting this research.
The complete X chromosome sequence was announced in 2020. However, until now, her Y-chromosome portion of the human genome contained large gaps.
“This is particularly important because the Y chromosome has traditionally been excluded from many studies of human disease,” said UCSC genomicist and study co-author Monika Cechova.
“The Y chromosome is the smallest, fastest-evolving chromosome in the human genome, and also the most repetitive, meaning that its DNA contains stretches of DNA that repeat over and over again,” Chekhova said. added.
The study characterizes a medically relevant region of the Y chromosome that contains a string of DNA (molecules that carry genetic information for the development and function of the organism) that contain several genes involved in sperm production. Became. The researchers say the new understanding of the genes on the Y chromosome could lead to practical applications such as fertility-related research.
“Many of these genes are important for fertility and reproduction, especially spermatogenesis, so we catalog not only normal variations, but also situations when, for example, azoospermia (absence of sperm in semen) occurs. If we can convert it, it could be useful for in vitro fertilization.
In addition to identifying several Y-chromosome genes, the researchers found that some DNA from that chromosome had been mistaken in previous studies as being bacterial in nature.
Scientists continue to expand our understanding of human genetics. His first description of the human genome was published in 2003. The first complete human genome was published last year, albeit containing a partial portion of the Y chromosome. In May, researchers released a new version of the genome that improved on the previous genome by incorporating rich diversity to better reflect the world’s population of 8 billion people.
Complete sequencing of the Y chromosome adds to this.
“We now have a recipe for how to fully assemble the Y chromosome, which is expensive at the moment, but could potentially be applied to personalized genomics in the future,” said Chekhova. Ta.
Reporting by Will Dunham, Editing by Rosalba O’Brien
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