Transcript: Solving the Genetic Puzzle 2 | May 31, 1990

A young man in a tuxedo juggles a few pins as he walks past a shop that reads “The Science Cafe” on the window. Another man hops up the stairs and waves his magic wand as he produces a bunch of flowers in his left hand.
The door opens. The man turns and hands the flowers to a woman dressed in white as she leaves the cafe.
A few people drink coffee at the counter. A server puts a menu on the counter and smiles.
A white slate with a black polka dotted diamond in the center appears. It reads “The Science Cafe” in light blue and pink.
The menu of the cafe appears. It reads “appetizers; Tidbits of discovery, simmering with excitement; slices of knowledge seasoned with perception; Tangy delights of wisdom and intelligence. Entrées; Chunks of scholarship laced with enchantment; nourishing morsels of science facts and breakthroughs; Sustaining portions of education and information; Fascinating helpings of philosophy and Learning.

The Science cafe proudly offers food for thought; Fragile Nature Forum, Solving the genetic puzzle, Part two; Cystic Fibrosis. Producer and director Michael Kushner, Researcher Nadine Galszcchy.”

Cathleen appears on screen. She has short wavy blond hair and wears a green jacket and a pink and light blue silk neck scarf. A caption below her reads “Cathleen Morrison, Executive Director Canadian Cystic Fibrosis Foundation.”

She says CYSTIC FIBROSIS AFFECTS A
GREAT MANY ORGANS IN THE BODY,
PRINCIPALLY THE EXOCRINE
GLANDS, BUT THE LUNGS ARE
INVOLVED, THE PANCREAS,
THE DIGESTIVE SYSTEM,
THE SWEAT GLANDS, THE
REPRODUCTIVE SYSTEM.
AND THERE IS A WHOLE ISSUE
OF BACTERIAL INVOLVEMENT
AND VIRAL INVOLVEMENT
IN THE LUNGS.

A clip shows a woman pressing down on a little girl’s chest and helping her to breathe in on a hospital bed.

She explains THERE'S TOO MUCH
MUCOUS IN THE BODY.
THERE IS A PROBLEM WITH THE
WAY CERTAIN SALTS, SUCH AS
CHLORIDE, PASS ACROSS THE
MEMBRANES OF CELLS, WHICH ARE
AFFECTED IN THE DISEASE.

The little girl breathes heavily and coughs up some mucus into a container.

Cathleen continues AND ALL OF THESE AREAS COMMAND
SCIENTIFIC INTEREST AND
ATTENTION AND ARE THE FOCUS
OF STUDY TOWARDS THE GOAL
OF BETTER TREATMENT.

A caption below Cathleen reads “The C.C.F.F funds research with community, private and corporate donations.”

A female narrator says CYSTIC FIBROSIS IS THE MOST
COMMON GENETIC DISORDER AMONG
CAUCASIANS IN NORTH AMERICA.

A clip shows people walking down a busy street.

She continues IN 1964, FEW OF THOSE AFFECTED
LIVED PAST THE AGE OF FOUR.

A caption on screen reads “Primary symptoms, Constant productive cough. Appetite but weight loss. Frequent, large, foul bowel movements. Salty-tasting skin. Repeated or prolonged pneumonia.”

She continues TODAY, LIFE EXPECTANCY HAS
INCREASED TO 25 YEARS AND
BEYOND, WITH IMPROVED
MANAGEMENT AND TREATMENT
OF THE SYMPTOMS.
THIS IS AMONG THE HIGHEST
RATES IN THE WORLD.
THE DETECTIVE WORK THAT WENT
INTO FINDING THE ELUSIVE
CF GENE IS A STORY OF DOGGED
PERSEVERANCE AND MARVELLOUS
ACHIEVEMENT BY A TEAM OF
DEDICATED RESEARCHERS,
DOCTORS, AND SCIENTISTS.

A slate appears. It reads “The discovery resulted from combined team work. Principal contributors, among many; Doctor Francis Collins and team; University of Michigan.
Doctor Jack Riordan and team, Biochemistry.
Doctor Manual Buchwald and team, Genetics.
Doctor Lap-Chee Tsui and team, Genetics, The hospital for sick children.”

She narrates CYSTIC FIBROSIS IS A
RECESSIVE GENETIC DISEASE.

Bat-Sheva appears on screen. She’s in her thirties; has short brown hair and wears a white t-shirt. She sits in a lab. A caption below her reads “Bat-Sheva Kerem, HSC genetics laboratory.”

She says RECESSIVE GENETIC DISEASE
MEANS THAT YOU NEED TWO COPIES
OF THE DEFECTIVE GENE IN
ORDER TO EXPRESS THE DISEASE.

A graph appears on screen. It shows two columns above representing the parents genetic pattern and reads “Carrier” below each column. Below the 2 columns four more appear. The first one is labelled “C.F” the second and third are labelled “carrier” and the fourth is labelled “normal.”

She continues YOU CAN GET THE DISEASE ONLY
IF BOTH OF YOUR PARENTS
ARE CARRIERS.
THE CHANCE IS ONE IN TWENTY
THAT BOTH CARRIERS WILL
BE CARRIERS.

The words “carrier” turn red and flash.

She continues AND THEN IT IS ONLY 25 PERCENT
FOR EACH CHILD TO GET THOSE
CHROMOSOMES AND
HAVE THE DISEASE.

The word “CF” then turns red and flashes.

She says IF YOU DO HAVE ONLY ONE GENE
WHICH HAS THE DEFECT, AND THE
OTHER GENE IS NORMALLY, YOU
WON'T HAVE THE DISEASE.
YOU'LL BE A CARRIER.
THIS IS THE SITUATION
WITH ALL THE PARENTS.
WE THINK THAT THE GENE IN THE
HUMAN BEING IS SO LARGE,
70 PERCENT OF PATIENTS HAVE ONE
SUBTLE MUTATION, WE PREDICT FROM
THIS, ALL OTHER MUTATIONS
WILL BE VERY SUBTLE, AND IF
YOU HAVE A MAJOR MUTATION,
YOU WON'T SURVIVE.
YOU CAN KNOCK OUT JUST A BIT
OF THE FUNCTION OF THE BODY,
BUT NOT MORE THAN THAT.

Fast clips show a doctor opening a refrigerator and pulling out some samples.

The narrator says THE MICHIGAN AND TORONTO TEAMS
WERE PURSUING THE INTANGIBLE.
SOME BASIC FACTS
WERE CLEAR THOUGH.
DNA CONTAINS SPECIFIC MARKERS
WHICH ACT AS SIGN POSTS THAT
COULD POINT TOWARD
THE ELUSIVE GENE.

A computer image shows a DNA line with markers on the lower end that read “917” “met” “J3.11 (D758)” the last two markers are joined by brackets and labelled 1 to 5 mb.
The other side of the DNA line has a series of numbers in a column next to it and a fraction “P over q”
She continues TO PLOT THE CHROMOSOME, THE
SCIENTISTS EXPLOITED THE
COMPLEMENTARY CHARACTERISTICS
OF SINGLE-STRAND DNA.

An animation shows blocks labelled with letters “C, A, T, G” on the left of the screen. Some other blocks labelled “T” “C” “A” move from right to left and adhere to the previous blocks.

She continues PROBES OF KNOWN GENETIC
MATERIAL BIND WITH THEIR
COUNTERPARTS IN CELL SAMPLES.
FAIRLY QUICKLY, RESEARCHERS
FOUND MARKERS FLANKING THE
CYSTIC FIBROSIS GENE, LOCATED
SOMEWHERE ON THE LONG ARM
OF CHROMOSOME 7.

A clip shows a microscopic view of chromosomes moving like strands of hair from the centre to the sides.

Lap-Chee appears. He’s in his late thirties; he has straight brown hair and wears glasses, a light blue shirt and khaki trousers.
A caption below him reads “Doctor Lap-Chee Tsui, H.S.C Genetics Laboratory.”
He sits at his desk in front of a computer screen and says
IN FACT, A STUDY WE'VE DONE
IS TO FOLLOW THESE SO-CALLED
SIGN POSTS OR MARKERS FROM
ONE GENERATION TO ANOTHER.
IF TWO GENES ARE CLOSELY
TOGETHER IN THE GENOME, OR ON
ONE CHROMOSOME, THEN THE TWO
GENETIC TRAITS, OR THE MARKERS
WILL BE INHERITED TOGETHER.

A black slate appears. It reads “Conserved region of DNA, indicates possibility of gene” as a title. And shows a yellow horizontal line with labels on some vertical lines on it that read “EccoRI” “Accl” and so on.

He continues AND THAT'S THE WAY WE FOUND
WHERE THE CF GENE IS,
BY FINDING ITS NEIGHBOUR.

The narrator says IN SHORT ORDER, THE QUEST
WAS NARROWED FROM 3 BILLION
NUCLEOTIDE BASE
PAIRS TO 250 thousand.
STILL A FORMIDABLE NUMBER.
THE SEARCH CONTINUED USING
CELL CULTURES OBTAINED FROM
HEALTHY DONORS, AND FROM CF
PATIENTS AND THEIR FAMILIES.
THESE SAMPLES WERE OBTAINED
IN 1982 AND ARE PERMANENTLY
STORED IN THE LAB.

A doctor sucks up liquid from sample jars lined up in front of her.

The narrator explains NEW CELLS CAN BE CULTURED
INDEFINITELY FROM THESE
LIVING ORIGINAL ONES.
A KIND OF CLINICAL
IMMORTALITY.
THIS CONSTANT SOURCE OF
IDENTICAL DNA MATERIAL ENSURES
THAT MOST OF THE VARIABLES
HAVE BEEN REMOVED FROM THE
MAPPING PROCESS.

A clip shows a doctor pouring some blood into a test tube.
It then shows the doctor putting the samples into a container and testing it. She later pulls it out and shows the test tube with pink liquid and white sediment at the base.
A caption below the image reads “White blood cells.”
Lap-Chee says WE ACTUALLY COLLECTED BLOOD
FROM PATIENTS, AND THEIR
PARENTS, AND THEIR
BROTHERS AND SISTERS.
WE EXTRACTED DNA FROM THESE
CELLS TO DO THE STUDY, AND
ALSO WE HAVE ESTABLISHED CELL
LINES FROM THESE INDIVIDUALS.
AND BY GROWING THEIR CELLS UP,
WE HAVE UNLIMITED SUPPLY OF
THEIR DNA, AND FROM THAT,
WE'RE ABLE TO DO A LOT OF
DIFFERENT STUDIES.

The narrator continues TO TACKLE THIS IMMENSE
MAPPING PROCESS, WALKING AND
JUMPING PRACTICES WERE USED.
BOTH METHODS UTILIZED PROBES
OF DIFFERENT RESOLUTIONS.
GENE JUMPING SPANS HUNDREDS
OF THOUSANDS OF NUCLEOTIDE
BASES AT ONCE.

A blue slate shows the processes utilized. A series of arrows and arcs appear parallel to the DNA strand image. A caption on the slate reads “Arcs show jumps; Arrows show walks.”
Below the image a caption reads “Jumping skips repeating DNA and seeks gene sites quickly.”

She continues THIS SKIPS REPEATED SEQUENCES
OF UNCLONABLE DNA CODE,
IN AN EFFORT TO QUICKLY
FIND MORE PROMISING AREAS.
WALKING TECHNIQUES TAKE A
MUCH CLOSER LOOK AT THE DNA,
AND PROVIDE A MORE
DETAILED BLUEPRINT.

The caption changes to “Walking maps DNA in detail. It reveals the blueprint of life.”

She says OVERLAPPING PROBES ENSURE THAT
CONTINUOUS SECTIONS OF THE
CHROMOSOME ARE CHARTED.

Johanna appears on screen. She sits in her lab wearing a light green t-shirt. She’s in her thirties; has wavy blond hair in a bob and wears glasses. A caption below her reads “Johanna Rommens, H.S.C Genetics laboratory.”

She says FOR MUCH OF OUR WORK, IT
WAS CLEAR WE HAD TO LOOK
EVERYWHERE FOR THE GENE.
WE THOUGHT WE WERE THAT CLOSE.
WE HAD TO JUMP, BUT WE ALSO HAD
TO COMPLEMENT IT WITH A WALK.
WE COULDN'T LEAVE ANY PORTION
OF THE CHROMOSOME ALONG
WHICH WE WERE WALKING AND
JUMPING LEFT WITHOUT LOOKING
AT IT FOR GENES.

A clip shows a machine stirring several bottles with amber liquid inside.

The narrator says THE WALKING OR MARKER
PROBES ARE PROPAGATED IN
E. COLI BACTERIA, THE SAME
KIND FOUND IN OUR INTESTINES.
THIS BACTERIA PRODUCES DNA
MARKERS FOR COMPARISON
WITH PATIENT SAMPLES.
IT WORKS QUITE WELL BECAUSE,
IN ESSENCE, ALL ORGANISMS
SHARE THE SAME KIND OF DNA.
TO SEPARATE THE LARGER AND
SMALLER PROBES, A GEL IS
PREPARED INTO WHICH
THE DNA IS PLACED.

A clip shows Johanna sucking up liquid with a test tube and placing it in a blue gel.

The narrator says A DYE IS ADDED WHICH STAINS
THE GENETIC MATERIAL.
AN ELECTRICAL
CURRENT IS APPLIED.

A clip shows Johanna plugging in a machine. A caption below the image reads “Pulsed field gel electrophoresis.”

She explains THIS ROUTINE PROCESS IS
CALLED PULSED FIELD GEL
ELECTROPHORESIS.
BECAUSE DNA IS A CHARGED
MOLECULE, IT WILL SLOWLY
GRAVITATE THROUGH THE GEL.
SIZE AFFECTS MOBILITY.
SMALLER PIECES WILL MOVE
FASTER THAN LARGER ONES.
EXPERIENCE DETERMINES WHICH
MARKERS WILL BE USED FOR A
GIVEN TEST.
THE DIFFERENT SIZES ARE
CLEARLY VISIBLE UNDER
ULTRAVIOLET LIGHT.

Two parallel amber lines appear; the light is switched to ultraviolet and the lines turn red.

The narrator continues SPECIAL RESTRICTION ENZYMES
ACCURATELY CUT THE DNA IN
PRECISE LOCATIONS TO PRODUCE
THE CORRECTLY SIZED PROBE
REQUIRED FOR MAPPING.

A clip shows Johanna sucking up material in a test tube and performing the actions described by the narrator.

She explains THE GEL BACKGROUND IS
SEPARATED FROM THE DNA IN
A TEST TUBE, WHERE IT IS
PURIFIED THROUGH PRECIPITATION
WITH THE ADDITION OF
SALTS AND ETHANOL.
IT IS SEPARATED FROM THE
BACTERIAL BASE IN WHICH IT
GREW, AND FROM THE PROTEIN
ENZYMES USED TO CUT IT.
THE MARKERS ARE TAGGED WITH
A RADIOACTIVE SULPHUR
S 35 ISOTOPE.
THEY WILL ONLY BOND WITH THE
COMPLEMENTARY STRANDS IN THE
PATIENT SAMPLES IN AN ATTEMPT
TO RECREATE THE DOUBLE HELIX.

A clip shows a man in his thirties sitting over a screen and analyzing the DNA strands under a microscope.

She continues THE DNA IS AFFIXED TO A
POLYCHROMIDE GEL MATRIX
WHICH DIVIDES THE CHEMICAL
CONSTITUENTS INTO
DISCRETE LANES.
THE DETAIL IS EXTREMELY GOOD.
THE RESULT OF THIS BONDING OR
HYBRIDIZATION CAN BE SEEN
ON THE AUTORADIOGRAM.
THE PRESENCE OF PARTICULAR
CHEMICALS IN THE DNA MOLECULE
SHOWS UP AS BLACK
BANDS ON THE X-RAY.

The man sits in front of vertical lines with smaller black bands and counts them using a pencil.

The narrator says THIS UNIQUE GENETIC PRINTOUT
IS PAINSTAKINGLY TRANSFERRED
BY HAND.

The man then writes down some letters on a paper next to him. He jots down G.T.A.A.A, etcetera.

The narrator continues IF FLUORESCENT TAGS ARE
USED, THE SEQUENCES CAN BE
AUTOMATICALLY
COMPILED BY MACHINE.

Rick stands in front of a large gray machine that reads “Genesis 2 thousand; DNA analysis system. He’s in his thirties; has short brown hair and wears a moustache.
A caption below him reads “Rick Rozmahel, H.S.C genetics laboratory.”

She continues IT WAS THIS RESEARCHER, USING
THIS COMPUTER, WHO CAUGHT THE
MINUTE DIFFERENCE BETWEEN
THE GENETIC MATERIAL OF
UNAFFECTED INDIVIDUALS AND
THOSE WITH CYSTIC FIBROSIS.
THIS IS A NORMAL CF GENE.

A clip shows a two lines with black bands across them at different heights.

She says THIS ONE IS DEFECTIVE.

A caption appears overwritten on the image. It says “Normal” on the left strand and “defective” on the right strand.
Below it reads “Small portion of gene only.

She continues OUT OF 6 thousand 500 BASE PAIRS IN
THE CF GENE, ONE TRIPLET OF
LETTERING IS MISSING, CTT.

A red circle highlights three bands on the left strand. It reads “CTT.”

She continues WHEN THE CELL ATTEMPTS TO
BUILD THIS SPECIFIC PROTEIN
SEQUENCE THAT IS CODED AGAINST
THIS DNA TEMPLATE, A VERY
SUBTLE MISTAKE IS MADE.

The word “phenylalanine” appears on screen.

She says THE AMINO ACID, PHENYLALANINE,
IS EXCLUDED FROM THE PROTEIN.
THE RESULT IS A DEFECT WHICH
PLAYS HAVOC WITH AT LEAST
70 PERCENT OF THE AFFLICTED
CYSTIC FIBROSIS POPULATION.

Lap-Chee says PREVIOUSLY PEOPLE THOUGHT
THIS KIND OF STUDY WOULD NOT
BE POSSIBLE.
I THINK WE DEMONSTRATE THAT
THIS KIND OF SO-CALLED REVERSE
GENETICS APPROACH IS ACTUALLY
POSSIBLE FOR A GENETIC
DISEASE LIKE CYSTIC FIBROSIS.

Cathleen says THE GENE IS A MARVELLOUS
DISCOVERY, BUT IT ISN'T THE
FINAL ANSWER IN
CYSTIC FIBROSIS.
WHAT THE DISCOVERY OF THE GENE
FOR CF MEANS IS FOR THE VERY
FIRST TIME, SCIENTISTS WILL
BE ABLE TO PURSUE DIRECTLY
THE GOAL OF A CURE
CONTROL FOR CF.

Lap-Chee says I THINK PEOPLE SHOULD
BE GENERALLY OPTIMISTIC.
I THINK THERE WILL BE A BETTER
TREATMENT FOR CYSTIC FIBROSIS
IN THE VERY NEAR FUTURE.

An image of a little girl appears on a black slate. A caption below reads “Computer animation-Animations Drouin Inc. From Senior Biology; Protein Synthesis. The Science Cafe, Written by Mike Kushner.”

The caption changes to “For more information, write to The Hospital for Sick Children 555 University Avenue, Toronto, Ontario M5G 1XS.”

The caption changes to “For more information write to, Canadian Cystic Fibrosis Foundation, 2221 Yonge Street, Suite 601 Toronto, Ontario M4S 2B4.”

A logo appears. It reads “A production of TVO Ontario.”

“Watch part 3; Science and the Spirit.” Appears overwritten below.

Watch: Solving the Genetic Puzzle 2