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An anonymous reader quotes a report from The Conversation: The Y chromosome is a never-ending source of fascination (particularly to men) because it bears genes that determine maleness and make sperm. It’s also small and seriously weird; it carries few genes and is full of junk DNA that makes it horrendous to sequence. However, new “long-read” sequencing techniques have finally provided a reliable sequence from one end of the Y to the other. The paper describing this Herculean effort has been published in Nature. The findings provide a solid base to explore how genes for sex and sperm work, how the Y chromosome evolved, and whether — as predicted — it will disappear in a few million years. […]
Spoiler alert — the Y turns out to be just as weird as we expected from decades of gene mapping and the previous sequencing. A few new genes have been discovered, but these are extra copies of genes that were already known to exist in multiple copies. The border of the pseudoautosomal region (which is shared with the X) has been pushed a bit further toward the tip of the Y chromosome. We now know the structure of the centromere (a region of the chromosome that pulls copies apart when the cell divides), and have a complete readout of the complex mixture of repetitive sequences in the fluorescent end of the Y.
But perhaps the most important outcome is how useful the findings will be for scientists all over the world. Some groups will now examine the details of Y genes. They will look for sequences that might control how SRY and the sperm genes are expressed, and to see whether genes that have X partners have retained the same functions or evolved new ones. Others will closely examine the repeated sequences to determine where and how they originated, and why they were amplified. Many groups will also analyze the Y chromosomes of men from different corners of the world to detect signs of degeneration, or recent evolution of function. It’s a new era for the poor old Y.
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