Y Chromosome

Context: Many animal species have a genuine fear of losing the Y chromosome in the distant future. This has happened in some species that have naturally lost this chromosome. About Chromosome:
  • It is a part of a cell in living things that decides the sex, character, shape, etc. that a person, an animal or a plant will have.
Sex Chromosome:
  • In humans, in addition to the 22 pairs of chromosomes in each, we have a pair of sex chromosomes called X and Y.
  • Sex as a specification is determined by these sex chromosomes. They carry sex­-determining genes.
  • All biological males have X and Y chromosomes and all biological females have two X chromosomes.
    • The ‘sex­-determining region Y’ on the Y chromosome determines the biological male sex.
Y Chromosome:
  • It is estimated to have emerged around 200­-300 million years ago in a common ancestor of all mammals.
  • The Y chromosome, is often referred to as the master of maleness.
  • Scientists published the complete genetic sequence of the Y chromosome in 2003. 
  • This sequence provided an outline of 23 million bases of the 60 million or so bases that together make up the Y chromosome.
  • In total, the chromosome encoded for only 55 genes and accounted for around 2% of the genetic material inside a cell.
Loss of the Y Chromosome in Humans: 
  • Men lose the Y chromosome (LoY) with age and this is associated with a higher frequency of cancers, Alzheimer’s disease, and a shorter lifespan. This has been corroborated by studies on mice models.
  • The human Y chromosome is about one-­third as big as the X chromosome. So, many animal species, including humans, have a genuine fear of losing the Y chromosome in the distant future.
  • Species such as rodents have naturally lost their Y chromosome.
Additional Information: Juvenile Delinquent: Many researchers jokingly refer to the Y chromosome as the juvenile delinquent among chromosomes due to
  • Its abundance of repetitive sequences
  • Poor functional utility (with a small number of genes)
  • Reluctance to socialise (i.e. recombine with other chromosomes)
  • A high proclivity to degenerate over the course of evolution.
 News Source: The Hindu

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