Maliha Tanjum Chowdhury
Junior
School of Life Sciences
Independent University, Bangladesh
Junior
School of Life Sciences
Independent University, Bangladesh
“I am terrified by this dark thing
That sleeps in me;
All day I feel its soft, feathery turnings, its malignity.”
Like the poetess Sylvia Plath who wrote these lines, men of
wisdom have always recited one thing time and time again: that there are
monsters living inside us. I, for one, am sure that I am haunted. Every cell in
me, in fact, is haunted… But before I go any further, I must ask – how many of
you here believe in things such as monsters, ghosts or demons? Can you please
raise your hand? Hmm, not many I see. But that’s alright, because in the span of the next three minutes, I am sure I will have made believers out of all of you. And
so begins my story.
Let me take you back to a time around 500 million years ago. Down
below in earth’s seven seas, life is flourishing without bounds. Several types
of complex, multicellular animals have already evolved. But, while the realm of
the living thrives, an enemy lurks in every corner of this vast kingdom. A
creature that stands as an exclusion to life itself, as it does not eat,
digest, or excrete like any of the living creatures. It is a tiny vessel of
protein holding in its genetic material with just one purpose – to invade and
multiply. These tiny yet monstrous entities are called viruses.
Endogenous retroviruses in sharks, the oldest surviving jawed vertebrates, and other existing organisms helped determine the time of origin of retroviruses
Now, around the
time of our story, a special new kind of virus came into being. In their war
against animal cells, viruses typically employ an explosive battle strategy
where they invade and pillage the cells, and then leave it to die. But these new viruses, called retroviruses, refrained from taking such a crude approach. Retroviruses, which still persist, incorporate their genetic material right into the host DNA, hiding in
plain sight. The cell is now "possessed" by this monster, which slowly but often surely consumes its host instead of killing it right away. The most-well known
retrovirus, HIV, does this to our immune cells, rendering them non-functional,
and giving people AIDS.
Things look bleak for the poor besieged cell, but it is
about to get much worse. Retroviruses which get woven into the DNA of germline
cells, which include sperm and egg cells, gain the ability to be transferred
into the animal’s babies as well – and thus, family curses are born. Animals do
not sit idle, and have evolved to harbor defenses to deactivate these
retroviruses, but remnants of the viral genetic material linger on in the host.
Millions of years down the line, these invading genes are just specters. But
specters need not remain silent. The descendants of the ancient infected hosts
have unwittingly crafted quite the revenge. In a human cell, the pieces of DNA
that were once invaders now assist the cell in obliterating other viruses that
try to infect us.
The story of the ancient battle between the living realm and
the unliving viruses will never truly reach an end But these ghosts from the past have helped us
get where we stand today. Embrace your inner monster, because in the
end, it has only made you stronger.
Sources to explore more:
Maliha is a weirdo who somehow
believes she's from a different planet. But she likes Earth just fine, and is
fascinated by the science and beauty of life and has made it her purpose to
explore it. Besides this, her most burning desires include becoming a synthetic
biologist/ genetic engineer and running away with a heavy metal band.
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