Junk DNA, the precursor of modern mammalian pregnancy
THE mystery of what separated mammals that nurture their young ones for nine months from the marsupials and egg layers has finally been uncovered.
A study has found that many of the genes behind the development of modern mammalian pregnancy are controlled by genetic elements called transposons, long referred to as “junk DNA.” The research team from university of Yale in the US looked at the DNA of uterine cells from the possum, a marsupial that gives birth two weeks after conception and shelters its developing young in a pouch, and compared them with cells from armadillos and humans, which both carry their children to term in a womb. The uterine cells of armadillos and humans shared more than 1,500 genes that possums lacked.
The team also found about 13 per cent of these genes were near to a particular kind of transposon specific to placental mammals. These transposons made uterine cells sensitive to the hormone progesterone, encouraged cells’ development into the placenta and influenced a variety of other changes central to modern placental pregnancy. The paper was published in Nature Genetics on September 25.
We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.
Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.