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Hibernation
Trigger

  

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Volume IV, No. 1
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ODYSSEY is a magazine published
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Kentucky Research Foundation under
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Unlvenlcy Archives
Margaret l. King Library - North
University of Kentudcy
Lexington, Kentucky 40506

The Hibernation Trigger

Acres of Soybeans in a Test Tube

Earthworms in Jeopardy
The Lowiy But Critical Plowers of the Earth

Safer Mines
Research Summer Helps Decide Career

How Can This Marriage Be Saved?

A Talking History of Medicine in Fayette
County

Detecting Cancers Sooner

Black Poetry to the Neighborhoods

A Pathway to Understanding Cell Growth
and Cancer

Bach to Basics with Computers
Silicon Solar Cells

Directory of UK Researchers

University Archives
Margaret l. King Library - Nora!
University of Kentucky
Lexlnston, Kentucky 40506

 

  

The Hibernation Trigger

Something pulled the trigger. The
small, furry body slumped forward
and rolled into a tightly curled ball.
The woodchuck’s respiration, heart
rate and body temperature dropped
dramatically. Although there were no
visible signs of life, the woodchuck
was indeed alive. It had entered an
artificially-induced state in order to
survive the scarcity of food in winter.

Dr. Peter Oeltgen was hooked.
Only moments before, the woodchuck
had been squirming furiously as it was
injected with plasma from a
hibernating ground squirrel.
Something very powerful and very
miniscule in the blood was responsible
for the change in the animal's
condition and Oeltgen was going to
identify it. He named the unknown
substance the Hibernation Induction
Trigger (HIT).

Oeltgen, UK associate professor of
pathology and toxicology and head of
the chemistry section in Pathology
Services at the Veterans
Administration Hospital, became
involved in hibernation research in the
1970s after being invited by Loyola
University physiologist Wilma
Spurrier and U. S. Navy physiologist
Albert Dawe to join their research
team.

By Tawny R. Acker

 

Scientists used to consider hibernation
nothing more than a reaction to the cold
and a throwback to cold—blooded
ancestory. There was even debate as to
which animals were true hibernators.

Spurrier and Dawe had begun their
research in the late 1960s. Prior to
their work, hibernation was basically
a phenomenon for descriptive
speculation. Some scientists
considered it nothing more than a
reaction to the cold and a throwback
to cold-blooded ancestry. There was
even debate as to which animals were
true hibernators.

Now a generally accepted scientific

2

definition of hibernation is that it is a
unique phenomenon in which the
entire animal participates. This means
that each organ at tissue level may be
capable of entering the hibernating
state in which energy expenditure and
food consumption are minimal.
Ground squirrels, woodchucks,
brown bats and European hedgehogs
are the four major groups of animals

which are considered true hibernators.

That is, the animals' core temperature
drops approximately 30 degrees until
body temperature is only one or two
degrees above that of their
environment. Their heart rate slows
from as much as 100 to 150 beats a
minute to one or two beats a minute.
For instance, bats whose summer
active heart rate while in flight is over
1,000 beats per minute, slows in
hibernation to less than 10 beats per
minute. Respiration also slows and
oxygen consumption decreases.
Hedgehogs, for example, can continue
to live without taking a breath for 150
minutes. During hibernation the
animals have no urine formation and
no protein catabolism.

As the animals enter hibernation,
they experience something called
shivering thermogenesis. That is, as
the core body temperature drops, it

 

 er

ue
50

drops from the body’s trunk outward
to the limbs. This phenomenon is very
similar to the way a human's body
reacts as part of the symptoms of
hypothermia, the often deadly
condition which occurs as the body's
core temperature drops and the heart
fibrilates. However, in animals
experiencing thermogenesis, the heart
does not fibrilate.

them. In fact, they are actively
working toward their realization. A
Stanford University neurophysiologist
is studying the connections between
sleep, warm-bloodedness, and
hibernation. A physiologist from
University of California at Davis is
interested in applying the information
from hibernation research in
controlling weight.

I} humans were able to achieve the state of
hibernation, it could mean an immediate
cure for sleep disorders. It would also
provide a natural anesthetic and increase the
possibilities of successful match-ups for

organ transplants.

It is a crucial distinction in the way
the bodies of hibernators and non-
hibernators respond to the same
internal conditions. Whatever
chemical or hormonal substance that
allows hibernators to exist in the
neutral state between life and death
also gives their bodies resistance to
tumor formation and provides a
natural anesthetic which deadens their
reaction to pain. During hibernation,
the animals can sustain twice as much
exposure to radiation without harm
and organs removed from the animals
can exist for transplanting purposes
nearly twice as long as those taken
from the animals during an active
period.

In these terms, hibernation does
seem to possess the mythical qualities
attributed to it in Rip Van Winkle and
Sleeping Beauty—prolonged sleep,
without any disturbing side effects,
except the loss of time. And the
implications for humans are
staggering.

If humans were able to achieve the
state of hibernation, it could mean an
immediate cure for sleep disorders. It
would also provide a natural
anesthetic and increase the possibilities
of successful match-ups for organ
transplants. Exposure to higher doses
of radiation without side effects could
have positive effects for cancer
victims. And certainly weight loss and
gain could be more easily controlled.

Although these are only
speculations based on current
research, scientists are not ignoring

Peter Oeltgen

 

Oeltgen says it is now a matter of
identifying what triggers hibernation
in these animals and how the
substance can be transferred, refined
or recreated in other animals before
the speculations can become reality.

He is perhaps the researcher closest
to identifying HIT. The odyssey began
nearly two decades ago with the work
of Dawe and Spurrier and the addition
of Oeltgen and Dr. Robert Meyer,
now a professor at the University of
North Carolina.

In 1968 Dawe and Spurrier decided
to search the blood of hibernators for
an agent that might be responsible for
the regimented periods of activity and
sleep which characterize hibernations.

They carefully extracted blood from
a hibernating ground squirrel as it
slept in a hibernaculum—a cold
laboratory constructed to resemble a

continued on page 4

 

  

The Hibernation Trigger
continued

natural environment. The extracted
blood was then injected into two
summer-active ground squirrels,
which were also placed in the
hibernaculum. Within 48 hours, the
active squirrels were hibernating.
The following summer, Dawes and
Spurrier continued their research using
more animals. This time, 23 active
squirrels were injected with blood
drawn the winter before from
hibernating squirrels. Three squirrels
were also injected with blood from
hibernating woodchucks. Within 52

into fractions and testing each fraction
for HIT activity. He is particularly
interested in analyzing the specific
amino-acid sequence of HIT. His
research toward that end is being
financed by a genetic-engineering

firm.

“We are trying to make headway in
fully identifying the molecules in
HIT,” Oeltgen said. “When we do this
the clinical applications will follow.”

Perhaps the most dramatic
experiment in HIT research recently
occurred when Oeltgen, Dawes, and
Meyers injected the albumin-bound
HIT into a rhesus monkey.

“The change from testing rodents to

 

temperature and the monkey’s did
not," Oeltgen said. “But it would have
been interesting to see what would
happen if we could have given
repeated tests.”

An important observation the
researchers gleaned from this experi-
ment was that the HIT effect on the
monkey resembled the human
response to an opiate or an opium-
based drug such as morphine.

Repeating the experiment with
several monkeys, the researchers
observed the same results. Following ..
this clue to the identity of HIT,
Oeltgen dosed some of the primates
with naloxone, an opiate blocker that

The scientists had demonstrated that something in the animal ’5
blood was clearly responsible for triggering the chemical reaction
which caused hibernation.

days, the squirrels injected with
woodchuck blood and 20 out of 2.3
squirrels injected with squirrel blood
were hibernating.

The scientists had demonstrated
that something in the animal’s blood
was clearly responsible for triggering
the chemical reaction which caused
hibernation. Oeltgen then dubbed the
substance HIT and delved further into
the identification process.

From earlier experiments, Oeltgen
knew the substance was in the plasma
of the animals. He began to
methodically test the small molecules
from the plasma of hibernating
animals. Active animals injected with
the plasma containing the smaller
molecules did not hibernate. This
indicated that HIT was somehow a
part of a larger molecule.

Further experiments showed that
HIT was indeed a part of a larger
molecule and somehow bonded to the
blood protein albumin. Oeltgen’s
current research is aimed at isolating
HIT from albumin on a molecular
level. This requires separating albumin

primates might seem like a large jump,
but Meyers had the monkeys and I
had the molecules, and it seemed like
a good opportunity to observe the
reaction on an animal closely related
to man,” Oeltgen said.

The researchers injected a blood
protein from a hibernating woodchuck
into the ventricular space near the
monkey's hypothalamus which
controls body temperature and heart
rate.

Within 15 minutes, the monkey
began responding. Suddenly it
shunned food and began to yawn. Its
eyelids became heavy and it began to
gag. And it fell into what appeared to
be a deep sleep. But it was no
ordinary sleep. The monkey’s body
temperature dropped several degrees,
and its heart rate decreased by half.

Although the researchers will not
say that the monkey hibernated, they
agree that these changes are those
usually experienced only by
hibernators. “By definition a true
hibernator's heart rate decreases to
almost nothing, and the core
temperature drops to an ambient

halts the brain's receptors to the
opiate. The injected monkeys
abandoned their hibernation-like sleep
almost immediately.

Oeltgen says the implication is that
the trigger somehow activates the
brain’s opiate receptors directly or
indirectly. And he speculates that HIT
is an opiate-like molecule or a
neurophomone that causes the brain
to manufacture opiates. However, this
is a only a theory, but one Oeltgen
hopes to test.

More importantly, these
experiments removed the research
from the realm of strictly hibernating
animals and their habits. ”For the first
time our research demonstrated that
the HIT molecule can exert a profound
effect on a non—hibernating model, the
primate, without any life-threatening
effect,” Oeltgen said.

”Whether or not the benefits we
observe in the hibernators will prove
useful to man still remains to be seen,"
Oeltgen said. “But the indications are
positive and the implications
profound.”

 VB

it

Acres of Soybeans in a Test Tube

—
Genetic Engineering of o Cinderella Crop

A first glance into the lab reveals
neat stacks of Petri dishes, hundreds
of them. On closer inspection, those
smooth rounds of plastic display small
cream-colored blobs, some sprouting
tiny green ”mouse ears." On nearby
shelves, small vials hold bright green
leafy spindles a few inches long.

The globs actually are masses of
plant cells, the tiny ears, embryos.
The spindles are the more advanced
shoots.

These are soybean test tube babies.
They, along with some distant cousins
growing in the greenhouse, are
making agronomic history.

They don’t look different than other
soybean plants. What sets them apart
is their conception: not from a
fertilized zygote — sexual
reproduction —but from single
vegetative or “somatic” cells, perhaps
from a leaf, stem, flower, or seed.
With careful nurturing, the single
somatic cells were grown into whole
plants.

The leader of this lab and discoverer
of the soybean cell-to-plant
regeneration system is Dr. Glenn
Collins, cellular geneticist
extraordinaire in the University of
Kentucky College of Agriculture.

The mature, thriving soybean plants
grown from single microscopic cells
embody one of his research goals.
They also represent the path to
another — improving soybeans
through genetic engineering.

Developing a soybean cellular
system is a natural step in Collins' on-
going work. After joining the UK
faculty in 1966 as a tobacco breeder
and geneticist, he established a firm
reputation in traditional breeding
programs. In the early 705 Collins
became more and more interested in
nonconventional approaches to plant
genetics. A sabbatical leave in 1973 to
the John Innes Institute in Norwich,
England, helped build his interest in
cellular genetics.

Cellular genetics is part of a larger
field referred to broadly as

By Moira Skinner

biotechnology, or more specifically as
genetic engineering, explained Collins.
That means using cells instead of
whole plants, and includes molecular
biology, such as recombinant DNA,
gene splicing, cloning and similar
techniques.

“The theme of our laboratory,” said
Collins, “is to genetically alter plants
in a positive direction, either for
production purposes, so that they’re
easier to grow, or for utilization
purposes, for better food for people
and feed for animals."

Cellular and molecular genetics fills
the same purpose as traditional plant
breeding, he noted, and supplements
traditional methods. “It's just a

various manipulations. Culture allows
easy application of a selective agent,
like an herbicide, and identification of
the resistant cells. When the question
is disease resistance, it’s difficult and
risky to expose large numbers of
plants in the field to a disease
organism, but safe and simple to do so
in culture.

In the lab, the researcher also can
control environmental conditions such
as temperature or moisture, and keep
them from interfering with the
expression of plant or cell response,
Collins said.

As his cellular work with tobacco
progressed, Collins became interested
in applying the same techniques to

In two ounces of liquid in a culture flask,
Collins can grow 50 million cells. With
hundreds of flasks in the lab, at 50 million
cells each, he has available billions of cells
and innumerable difierent genotypes.

shortcut, a more efficient and
sophisticated approach at changing
the genetic composition of the cell —
the basic unit of a plant or animal.”

Working with masses of cells
instead of acres of whole plants offers
several advantages. Growing and
testing in the field is an effective
process in changing traits, but it is
slow and time consuming. Growing
enough plants for optimum genetic
variability is impossible or
impractical.

But in two ounces of liquid in a
culture flask, Collins easily can grow
50 million cells. With hundreds of
flasks in the lab, at 50 million cells
each, he has available billions of cells
and innumerable different genotypes.

That enables the geneticist to select
naturally occurring mutations or to
induce mutations and to perform

other field crops. When the College of
Agriculture decided to move deeper
into cellular genetics, and in 1978
created a full-time faculty position for
somatic cell research, Collins applied
and secured it. He soon took to the
lab with red clover and soybeans.

”We’ve also done some work in
corn and fescue," he said, “as we are
basically concentrating on the crops
that are most important to Kentucky.”

Indeed, the importance of soybeans
extends far beyond the
Commonwealth. The legume is an
extremely important oil and protein
source worldwide and is a major food
crop for humans and animals. It has
far more potential as a human food
than it now enjoys, especially if

continued on page 6

5

 

  

Acres of Soybeans in a Test
Tube continued

researchers succeed in changing the
distinctive flavor that has limited its
use.

”The soybean is a Cinderella crop
because it has such outstanding

characteristics as high protein content,

and good food and feed value, and it
is just ready to be utilized," Collins
said. “Interest has been strong, the
markets strong, and it has replaced
other crops in the production cycle,
especially in the Midwest.

”It’s changed agriculture. Even

Kentucky produces a lot of soybeans,
usually doublecropped with wheat so
producers can grow two crops a
year.”

There's a tremendous amount of
work to be done to make soybeans an
even stronger crop. Besides the
standard traits to improve in a crop
plant, such as disease resistance, insect
resistance, uniformity and tolerance to
herbicides, heat and drought,
geneticists also can strive to improve
the quality of the major product —
the seed — and the oil and protein it
contains.

So to Collins and others studying
legumes, the incentive was great to

The Stages of Plant Regeneration from Soybean Cell

Cultures-

 

Immature soybean embryos.

 

The first appearance of somatic embryos on callus
produced from an immature soybean embryo.

6

improve soybeans and to use cellular
and molecular techniques to do so.
But before applying genetic
engineering approaches to soybeans,
Collins faced a major hurdle. There
was no cellular system developed for
soybeans; that is, no one knew yet
how to reduce soybeans down to the
single cell level and then regenerate an
entire plant.

“For some reason,” Collins said,
“the large seeded legumes like
soybeans, peas and beans are difficult
to manipulate, while the small seeded
legumes like alfalfa, red clover, and
birdsfoot trefoil, are relatively easy.”

He and a former graduate student,
Greg Phillips, had developed a cellular
system for red clover, and laid the
groundwork for soybeans. They
published a journal article in 1981
showing how they derived tissue
cultures and pushed regeneration to
the point of obtaining embryonic
plants for soybeans. But the tiny
plants failed to mature. There was
more work to be done.

The prospect of a generous grant
from a seed company, Agrigenetics
Corporation, provided more incentive
for Collins to carry on the soybean
regeneration work. The company’s
representatives had approached
Collins first in 1981 with the intention
of supporting soybean research.

“At that time,” said Collins, “I told
them we just weren't far enough
along. We didn’t have the personnel,
we were short on lab facilities."

Fortunately, that situation changed.
By mid-1983, Collins had more
resources at his fingertips. The UK
College of Agriculture began showing
strong support of cellular and
molecular genetics research, not only
in agronomy, but throughout the
College. More labs were made
available and older labs renovated.
New researchers were recruited in
several departments.

“The strength in this kind of work is
numbers of people in different
specialties,” Collins said. ”We draw
upon people in plant pathology,
biochemistry, horticulture, any area,
if we have a need for a technique or
piece of equipment.”

The arrival of Dr. David
Hildebrand in 1982 boosted the
soybean research. Well-versed in plant
genetics, chemistry, and agronomy,
and fresh from a postdoctoral

fellowship studying biochemical
genetics in Japan, Hildebrand

 

 lr

ve

)n

id

:is

mt

 

Plon’rlei derived from d “germinated” soybeon embryo.

represented the molecular side of the
genetic engineering team.

“I was hired to be sort of a bridge
between plant breeding — traditional
plant improvement — and molecular
biology.” Hildebrand said. "My
obligation is to take the latest in
molecular genetics techniques and
improve plants, ultimately moving the
work to levels the breeders can
capitalize on.

”I found it was just what I was
looking for,” he added.

With Hildebrand on board, Collins
was ready to tackle the commitment
of the soybean regeneration work.

Agrigenetics accepted their proposal
and funded the work for a two-year
period beginning in December 1983.

”I think Agrigenetics was interested
in us for two major reasons," Collins
said. “One, our experience and
involvement with legumes, and
second, our track record. Without
sounding too boastful, we’re the most
advanced lab in the country for
tobacco, and I think also the top lab
for legumes.

”We have a large laboratory and a
productive record, and they knew that
we knew what they wanted us to do."

What Agrigenetics wants Collins

and Hildebrand and their colleagues,
including Dr. Paul Lazzeri, to do is
remove a bottleneck. The seed
company wants to put specific genes
into soybeans, to impart new
resistances to crop stresses or pests
such as plant diseases, insects, and
nematodes, and to improve drought
and temperature tolerance.

But until there's an effective cell-to-
whole plant system for a particular
plant, there's no way to transfer
genes.

"That’s why we have placed
research programs for regeneration
with people we believe to be
outstanding researchers throughout
the world," said Dr. Dale Hansen,
president of Agrigenetics Research
Corporation, the seed company's
research arm. “We have done that for
each of the major crops that we sell.

“That's why we're working with
Glenn Collins. He’s considered one of
the leading people on the forefront of
plant regeneration for soybeans.”

Agrigenetics has had its contract
with Collins for only a little more than
a year, but, Hansen commented, “he
has done very well during that short
period of time. This type of research
takes a long time to accomplish so we
don't expect miraculous results in a
year."

Yet Collins and his crew are within
months of perfecting the soybean cell—
to-plant regeneration system. They
have regenerated plants growing in the
greenhouse, some of them as far along
as flowering and producing seed.

A two-pronged strategy helped push
the work along at a rapid pace. First,
Collins and his associates, including
soybean breeder Dr. Todd Pfeiffer,
undertook a massive study of soybean
genotypes to find the most promising
for tissue culture. They looked at
more than 800 different genotypes to
pick out 20 or so with the best
response, instead of randomly taking
a few and hoping they could get
conditions right to make those few
respond.

The experimentation on
responsiveness yielded about 25
different genotypes, including some
wild genotypes that will hybridize
with cultivated soybean varieties.

“That’s been very good for us,”
Collins said, ”because in just the first
year we’ve regenerated plants from
cell cultures of two of the wild species,

continued on page 8

7

 

  

 

Acres of Soybeans in 0 Test
Tube continued

and we also have plants regenerated
from different cultivated soybean
genotypes, too.”

Another approach w the second
prong of their strategy — was finding
the best source of plant tissue to
introduce into culture. That piece of
tissue, called the explant, can come
from any part of the plant — flower,
stem, leaf, root or seed — and from
either mature or embryonic sources.

The UK researchers found exactly
what they predicted, that the most
responsive explant sources are
embryonic. They decided to
concentrate on immature flower buds
and embryos.

As Collins explains, ”The basis for
the response, we think, is that
embryonic tissues are still at a cell-
division, growing, active stage. They
are much more easily induced in
culture to continue division and to
differentiate back into plants.”

Taking plants down to the single
cell level and back up into new plants
is a complex, painstaking process of
nurturing. First, the researcher isolates
a complex tissue, say a piece of young
flower bud, surface sterilizes it, and
puts it in culture in a Petri dish. There
it is nourished by a medium composed
of sugar as the energy source,
chemicals, and hormones, and
exposed to optimal light and
temperature conditions.

The first response is that on the
explants cut surface, cells proliferate
in a tumorous mass, called a callus
(the cream-colored blob in the Petri
dish). After a few weeks on a solid
medium in the Petri dish, the callus
typically is transferred to a flask of
liquid medium and put on a shaker.
As the liquid is agitated, gases are
exchanged, and the mass of dividing
cells is broken into a finely divided
suspension culture, resembling chicken
broth afloat with little particles.

The cell division is so rapid that it’s
necessary to pour out half the
suspension culture weekly and add
more liquid to dilute it, or it would
become packed solidly with cells.

When the researchers decide it's
time to select cells, they pour the
suspension culture back onto a solid
medium and apply a selective agent,
perhaps an antibiotic that kills all but
resistant cells. These hardy survivors

8

 

Regenero’red plontlet potted
in soil.

form colonies, and after a few weeks
are placed on a medium especially
composed to stimulate plant
regeneration.

Once a plant emerges, it lives in the
lab until it reaches two to four inches,

then moves to a pot in the greenhouse.

The entire nurturing process, from
single somatic cell to entire plant, can
take as little as two months or as long
as two years. It all depends on the
manipulations — genetic engineering
or mutant selection, for example —~
performed on the suspension culture.

Collins is matter-of—fact as he
explains the complex, miraculous
procedure. But this established
researcher has sustained an
enthusiasm that breaks through in his
conversation.

”What really excites me is not

 

reducing a plant down to a single
cell," he said, ”but the fact that the
single vegetative cell is able to
regenerate the whole plant.

“It fascinates me that you can take a
single cell from a leaf of a plant,
isolate it, make a genetic change in it,
then put it under the right conditions
and tell it ~— a somatic single cell, not
a fertilized zygote — to regenerate
into an entire plant, and it does it.

”And it's generally a normal plant,”
Collins said, as if not quite believing
it. ”It is able to flower, produce seeds,
and pass the new trait on to its
progeny.”

The cell-to-plant regeneration
process, fascinating in itself, sets the
stage for the equally astounding
techniques of genetic engineering.
Close to unlocking the mystery of the
soybean cellular system, the UK team
is pushing hard now on the molecular
work.

The first goal is to alter the soybean
fatty acid composition. It seems
soybeans contain much more than
enough of a fatty acid called linolenic
acid, which results in an off-flavor.
Collins and Hildebrand hope to reduce
the level of linolenic acid in
commercial soybeans from the present
six to eight percent to one percent or
less. That would solve a problem for
the processing industry and remove an
obstacle to using soybeans for human
consumption.

Hildebrand has identified mutants
with very low levels of linolenic acid.
His plan is to isolate the gene which
triggers low linolenic content and to
transfer that gene to the familiar,
commercial soybean varieties. To do
so, he’ll use such molecular techniques
as gene cloning and splicing, and a
way of inserting new genes into plant
cells using the Ti plasmid.

“The Ti plasmid has been called
nature's genetic engineer," Hildebrand
said. ”It’s far and above the best
system for putting genes into plants
because bacteria does most of it for
you naturally.”

Here/s how the system works. The
scientist identifies the desired gene in a
plant cell, isolates the gene using
special chemical separations, and
clones the gene to increase its number.
Then the researcher puts the copies
into transfer vectors or carriers, and
that's where the bacteria come in.

The vector commonly used is a
bacterium that causes crown gall
disease, which is widespread in soil,

 

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and which infects tissues of plants like
tobacco, tomatoes, clover and
soybeans. The bacterium actually
enters the plant and splices in some of
its own genetic material, including the
new gene put in by the scientist. The
cells of the recipient plant incorporate
the foreign genetic material into their
genetic apparatus, and become
transformed.

Collins and Hildebrand are working
now on isolating genes involved in
lipid biosynthesis. They are also
perfecting soybean transformation
systems using the Ti plasmid such that
soybeans could be transformed with
lipid biosynthesis and other genes.
Once they develop the way to insert
genes into soybeans, the possibilities
for future improvements to the plants

“
fi .It's actually sort of overwhelming, when

you realize you can take a single cell from
an organism, manipulate it and change its
genetics, and then get a whole new
organism. It's a powerful capability. "

Professor Glenn Collins

”It's actually sort of overwhelming,
when you realize you can take a single
cell from an organism, manipulate it
and change its genetics, and then get a
whole new organism. It’s a powerful
capability."

The Ti plasmid system isn't fully
understood, said Hildebrand. ”As is
often the case in plant improvement,
we know how to use it long before we
understand the whole process."

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are many. Another tactic they may
take, for example, is to change the
amino acid composition of soybeans
to elevate the methionine level.
Although the plants have a high
protein content, they are known to be
low in that particular amino acid. it
turns out that methionine contains
sulphur, in which plant protein is
generally deficient. Increasing
methionine in soybeans would

Shown in the Culture Laboratory, the “nursery” for the soybean genetic
research, are Professor Collins and Postdoctoral Student Paul A. Lazzeri from
England. Dr, Lazzeri, under a fellowship from Agrigenetics, plays an integral
role in the research program.

therefore make their protein more
balanced and valuable for the human
diet.

After Collins and Hildebrand
succeed in changing traits in soybeans
and regenerating the desired plants,
their work will not be over. Many
evaluations will follow, to see what
will be transmitted to the progeny,