Authors: Hideaki Sena
Parasite Eve (44 page)
Asakura closed the journal.
Why did the mitochondrial
child have to melt into Toshiaki until it died? This was also a big riddle. But
Asakura thought she had an intuitive understanding where this tragic end was
concerned. After all, Toshiaki and the mitochondrial offspring were father and
child...
“Hey, Asakura, what are you
doing all alone up here?” came an unexpected voice. She turned around to see
the familiar face of a fellow student, one year behind her, who had also been
under Toshiaki’s guidance.
He removed some Eppendorf
tubes from the thermal cycler, solving the mystery of who had left the machines
running.
“Everyone’s been looking for
you. I wish you had told someone you were coming here.”
“Sorry about that. I just
wanted to take one last look around before I left.”
Asakura returned the issue of
Nature
to its shelf and smiled to cover the fact she had been crying.
The student placed his tubes
into a refrigerator and was about to close the door when he remembered
something.
“Oh, by the way, I found some
of Doctor Nagashima’s cells in deep freeze, but wasn’t sure what to do with
them. Would you mind taking a look?”
“Cancer cells?”
“No, I’m not sure what they
are.”
She followed him into the
equipment room. As he opened the large freezer door, a white mist billowed into
her face. The student pulled out a rack and looked inside.
“Here they are.”
He showed her a number of
blood serum vials.
The labels were frosted over.
She rubbed them With her fingertip.
Toshiaki’s handwriting.
She held her breath.
They were dated August of the
year before and marked “Eve 1.”
Her heart gave a thump.
“...Asakura?”
She forced a smile.
“Something wrong? You look
like you’ve seen a ghost.”
“It’s nothing. Is this all
you found?”
“These, too,” he said, and
showed her a bag filled with several dozen vials. Some were labeled simply
“Eve,” but there were also others numbered as “Eve 2” and “Eve 3.”
She was speechless.
These cells were being
preserved in preparation for primary culture. Though frozen now, if they
returned to room temperature, they would begin propagating all over again.
A cold shiver ran along her
spine.
“What are these? I’ll take
care of them if you want.”
“No, it’s okay. Let’s just
throw them out. Thanks for finding them for me. I’ll go put them in the
autoclave.”
“I can do it for you.”
“That’s okay. Just leave it
to me.”
Asakura gathered the vials
into the bag and tied it securely. She went to the Cultivation Room, her feet
picking up speed along the way.
None of these could be left
behind. She had to destroy them immediately.
She ran into the Cultivation
Room and opened the lid to the autoclave.
She threw the bag into it and
closed the lid tightly.
If she killed these, all that
would never happen again.
She was sure of it.
Just then, the back of her
neck tingled sharply.
She froze. It was that
sensation.
Asakura felt just a little
anxious.
There was still one thing she
could not explain. Why had Kiyomi’s mitochondria rebelled? Why not Asakura’s,
or Toshiaki’s? Why
Kiyomi
?
Was it simply a question of
polymorphism?
[40]
Everyone carried slightly
different genes. Had Kiyomi’s simply been different in such a way as to allow
mitochondrial hyperactivity?
If that were so, what Asakura
was about to do did not guarantee that mitochondria would never rise again. As
long as people could be born with genetic mutations like Kiyomi’s, there was a
possibility that mitochondria could evolve in them. If that was so, was it not
useless to hinder their evolution?
Asakura had no answers. Maybe
so, maybe not.
All she could do with any
assurance was to kill these cells.
“The party is winding down
now. They’re all asking for you,” said the young man from beyond the door.
Asakura smiled, then switched
on the autoclave.
Used in genetic engineering to
cut strands of DNA. EcoR I and BamH I specifically digest (or recognize) the
DNA motifs GAATTC and GAGCTC.
A workstation enclosed in glass
into which one places only the hands for sterilized handling of materials.
Purified air passes into the clean bench via a filtering system.
An immortal cell line cultured
from the epithelial (i.e. fetal) linings of lab mice. Normal rodent cells do not
divide more than ten times in a cultivation environment. Cancerous cells, on
the other hand, divide indefinitely. NIH3T3 cells are known for their ability
to propagate like cancerous cells while exhibiting traits of their healthy
counterparts. Their name pays homage to the American National Institutes of
Health (NIH), where they were first isolated.
Proteins that bind to a chemical
compound (retinoid) similar to Vitamin A
A series, or chain, of enzymes
that draws out energy by decomposing fatty acids. This response can be
observed, for example, in respiratory activity, in which β-oxidation
enzymes utilize oxygen to consume fatty acids, β-oxidation enzymes exist
in mitochondria and even in peroxisomes (one of four organelles in a cell).
Cells used to artificially fuse
cancer cells and lymphocytes. They are particularly useful for cellular
research, as they preserve the nature of lymph cells while multiplying
indefinitely.
Putting color into cultivation
liquid is standard practice to determine its acidity or alkaline level (pH).
Yellow=Acidic, Red=Neutral, and Purple=Alkaline. The condition of the cells is
clearly elucidated from its color.
A process by which cells are
extracted from internal organs (human or rodent) and then cultivated. When
pre-gathered cells such as NIH3T3 are cultivated, the initial stages are not
technically deemed a primary culture.
Whenever toxins such like
radiation or carcinogens give rise to genetic mutations, cell division is
affected, ultimately causing cancer. There are currently over 100 types of
cancerous genes known, with new mutations always being discovered.
These drugs suppress the body’s
natural refusal of foreign matter (in this case, a donated organ). At the same
time, however, this makes a recipient more easily prone to bacterial infection,
which can sometimes mean the difference between life and death.
A reagent used to prevent changes
in a given solution’s pH level. HEPES is virtually nontoxic and is ideal for
maintaining a chemically neutral environment.
Any group of proteolytic enzymes
that decomposes collagen and gelatin (i.e. cellular proteins).
A machine by which diluted cells
are collected through the use of centrifugal force. 50 G’s is the usual amount
of force applied by the machine, which spins at 700 rpm, creating an artificial
gravity 50 times that of the earth’s surface. In this context, being gentle
means to separate the cells carefully without damaging them.
Plastic receptacles that can hold
up to 2 ml. Their resilience makes them ideal for use in centrifuges and are
used often in genetic engineering. Costing only pennies each, they can be
disposed of freely after use. Though originally a product of its namesake
company in Germany, they are now manufactured by various other suppliers.
A capsule-shaped mixing tool,
consisting of a magnet covered in teflon. The stirrer is placed into beaker,
into which the solution to be mixed is poured. The beaker is then placed onto a
special machine. Another magnet inside the motor spins around, causing the
stirrer to spin inside the beaker.
Clear fluid above sediment or
precipitate in a test tube.
A device used to extract an exact
amount of a given solution anywhere from 0.2 to 1000 micro liters. In genetic
engineering, the usual amount used is between 10 and 100 μL. One μL
is equal to one cubic millimeter in volume.
Cells can be preserved by
freezing them while still alive. This requires a slow cool down in a special
preservation liquid, dropping the temperature by one degree per minute. In this
way, the cells suffer minimal damage.
Kiyomi’s
liver cells were glowing
Cells treated with collagenase
appear as glowing globules when viewed under a phase contrast microscope. Dead
or dying cells are opaque and a cell’s condition can be judged according to its
luminosity. If left for a number of hours, cells aggregate to the bottom of the
flask and lose their brightness.
In addition to the nucleus and
mitochondria, cytosol is another important cellular component. Mitochondria are
actually stuck to a mesh structure called tubulin, so they are unable to move
around freely. In longer cells such as nerve cells, they unite with these
“motor proteins” to achieve movement. Free-swimming mitochondria are thus rare.
The name Kiyomi is comprised of
two characters, the first meaning “holy” and the second “beauty”. When the
first character is used in conjunction with that for “night”, the resulting
compound means “Christmas Eve”.
There are various sizes of plates
which have small depressions (wells). The number of available wells ranges from
6 to 96. In a 6-well plate, 2 mL can be put into each 3.5-cm diameter well.
Genes coding for a large portion
of mitochondrial proteins can be found in the nucleus: the nuclear gene products
generated as precursor proteins must be imported into mitochondria. MOM19, a
protein in the mitochondrial membrane, is essential for this importation.
In a first generation
cultivation, the qualities of each cell differ slightly, because the inherent
nature of each cell changes during the culturing process. In order to acquire
uniform cell groups, a succession of cells is replicated from a single cell.
This is called cell cloning. There are innumerable methods for cell cloning,
but the so-called “critical dilution” method is the most widely used of all. In
this method, one dilutes a cellular solution and cultivates no more than one
cell per plate well. Inside each well, the cells that multiply are virtually
identical to the cell from which they propagate. Eve 1 and Eve 2 propagated in
separate wells. Therefore, each is a unique clone group. This is different from
genetic cloning.
A way of detecting and
quantifying a specific RNA. RNA can be separated into the following
sub-classifications: ribosome RNA (rRNA), transfer RNA (tRNA), and messenger
RNA (mRNA), among others. The person who devised the DNA detection method was
named Southern, so his method came to be known as the Southern blot. RNA is,
appropriately enough, “Northern”. A Western blot detects proteins. There are
“Eastern” and “Southwestern” methods as well. The amount of β-oxidation
enzyme produced is largely determined by the amount of mRNA coding the protein
in question.