Download DQ_SIN_11_14_2005

New Genetic Map Called a Powerful Tool for Medical Science
Written by Jerilyn Watson and Caty Weaver
14 November 2005
This is SCIENCE IN THE NEWS in VOA Special English.
I'm Bob Doughty.
And I'm Pat Bodnar. This week -- news about a genetic map that is being called a
powerful new tool for medical research ...
Then, a report on an ancient Christian church found under an Israeli prison ...
And Angola says a recent outbreak of Marburg virus is over.
Small genetic differences make one person different from another. Now medical
researchers have a new map to help them find these differences. More than two
hundred scientists from six nations developed the HapMap. The name comes from the
word haplotype.
A haplotype is a group of differences that are likely to collect close together, in a block.
These blocks appear to pass from parent to child. The HapMap scientists hope to
identify up to six million DNA differences before they finish.
The scientists say the findings may lead to identifying genes that cause common
diseases like diabetes and heart disease. Linking diseases to genes could lead to new
treatments. People could also learn if they have an increased risk of a disease because
of their genes.
In some cases, such knowledge might lead to preventive action. For example, people
whose genes show a possibility of developing diabetes could take steps like trying to
control their weight. But for a condition like Alzheimer’s disease, nothing known
today could prevent it.
The scientists have published their work in Nature magazine and on the Internet at
hapmap dot o-r-g (hapmap.org).
An organization called the International HapMap Consortium organized the study.
1
The work involves researchers from Britain, Canada, China, Japan, Nigeria and the
United States.
The new map is based on DNA from two hundred sixty-nine people. They represent
four ethnic groups: European, Japanese, Chinese and Yoruba.
Project leader David Altshuler works at Massachusetts General Hospital and Harvard
Medical School. He also directs medical and population genetics at the Broad Institute
in Massachusetts. Another project director, Peter Donnelly, is from Oxford University
in England.
Doctor Altshuler calls the HapMap a powerful new tool to explore the root causes of
common diseases. It is more difficult for scientists to find genes linked to common
diseases than to rare ones.
For example, one single gene may be responsible for a rare genetic disease within the
same family over the years. But several genes may cause a person to be more likely
than others to get some kinds of cancer.
The HapMap Project developed from information provided by the Human Genome
Project. That project was completed in two thousand three. It identified all the
chemical pieces in DNA, the genetic material in cells.
DNA has more than three thousand million building blocks. A series of these building
blocks forms a gene. For any two people, the building blocks are almost all the same.
But extremely small differences can mean that one person has a higher risk of disease.
One kind of difference is called a SNP [pronounced snip]. There are millions of places
where SNPs can happen. The HapMap Project is identifying common places where
they are found.
Studying haplotype blocks will make it easier to find the genes suspected of causing a
disease. The researchers may be able to investigate which blocks of DNA are common
among people with the same disease. The process would be much faster than
examining every piece of DNA.
2
Stacey Gabriel of the Broad Institute says mapping just one SNP used to cost almost a
dollar per patient. Today, she says, it often costs less than one cent. In the past, it
was possible to test only one hundred genotypes in a day. But now, she says, it is
possible to perform millions of tests in a day.
In the past, some scientists have questioned whether using haplotypes is the best way to
find genetic information. Some still express concerns about the effectiveness of this
method. But several studies already have been published using the new information.
For example, scientists at Yale University in New Haven, Connecticut, used the
HapMap to connect a gene to macular degeneration. That is a leading cause of
blindness in older people.
You are listening to SCIENCE IN THE NEWS in VOA Special English, from
Washington.
***************************** (7’20” mark)
Palestinians in a prison in Israel have found the ruins of an ancient (1) Christian place of
worship. Some archaeologists say it could be the oldest church ever found in the
homeland of Jesus. But other experts say it is unlikely the church is as old as (2)
suggested. (7’45” mark)
The prison is in Megiddo. Israeli officials had ordered a (3) dig to search for ancient
objects before (4) a planned addition to the prison. The government often orders such
digs before building in historically important areas. Megiddo is where the battle of
Armageddon takes place in the Bible.
The Israeli Antiquities Authority began the dig months ago with about sixty prisoners
for labor. On October thirtieth, one of them discovered the floor of the ancient
building. Archeologist Yotam Tepper, the leader of the dig, called it (5) "the find of a
lifetime."
The floor is about (6) six meters by nine meters. It is formed by two mosaics made
from stones of different colors and shapes. One of the mosaics represents a traditional
Christian symbol, a fish.
3
The mosaic also includes several messages. The Israeli Antiquities Authority says one
appears to be from a Roman soldier. The message says he paid for the mosaic to (7)
seek honor. It also names the maker of the mosaic. Researchers say another message
lists the names of four women as a remembrance.
Archeologists say they also found what may have served as a base for a structure from
which (8) to lead religious services. Nearby is a third message, believed to say: "The
God-loving Aketous has offered this table to the God Jesus Christ, as a memorial.”
Pieces of cooking tools and containers for wine were also found on the floor of the
structure. Mister Tepper says (9) the pottery dates to the third century. He says the
kind of Greek writing used in the messages also represents (10) that time period.
And Mister Tepper says the design of the structure is simpler than those of churches that
came after the third century.
Experts in the history of Christianity generally believe that churches did not exist until
the fourth century. Christianity was banned until Emperor Constantine of Rome made
the religion legal in the year three-thirteen. Experts argue that it was too dangerous
before then for Christians to worship in public, so they did so in secret.
As a result, one expert questions if a Roman soldier in the third century would have
taken the risk to place a message on a mosaic in a church. He says such a violation of
law, if discovered, would have meant the end of the man’s service. (11) It might have
meant the end of the soldier, too.
One theory is that the church may have been established later than (12) the Roman
building that housed it.
The mystery of the ancient church should be settled in time. Archeologists say only
about ten percent of the area has been uncovered so far. Israeli officials now have to
decide how to deal with a valuable archeological site on the grounds of a prison.
***************************** (12’ mark)
4
Comprehension Questions
1. Explain in your own words.
2. Who suggested what?
3. Another word for this?
4. What does this mean?
5. What does this mean, literally and otherwise?
6. What are these numbers?
7. To do what? Why did the Roman soldier do it?
8. “To lead religious services” means?
9.
10.
11.
12.
Dates () to the third century: Fill in the blank on the left.
When?
What might have happened to the soldier?
What is the relation between the Roman building and the church?
Discussion Questions
1. Do you think historical objects and relics should be preserved at the expense of
development? If you have to choose between preservation and development, which
would be your choice?
2. Do you think endangered species should be saved at the expense of development?
What if the problem of endangerment has no ties with environmental deterioration?
3. Do you think minority languages should be preserved at a financial cost?
4. Some say it is best if one language conquers the world as it facilitates ready
communication and removes one potential cause of a conflict. Do you agree or
disagree? Give concrete reasons for your opinion. Note that we are talking in
general terms and are not necessarily assuming that that one language is English.
5. What do you think is the root cause of Japanese students’ extremely poor
proficiency in English?
Google の mailing list を教材配信に利用する事にしました。名前と所属と電話と
email を書いた email を僕に送って下さい。[email protected] です。既に Google
の会員の人も、上記が無いと mailing list (= Google group)に入れません。
5
The government of Angola says the recent outbreak of Marburg fever there has ended.
Health Minister Sebastao Veloso said last week that there have been no recorded cases
of the disease since July.
The Marburg virus is spread through contact with bodily fluids. It can cause high body
temperature, organ failure and severe bleeding. There is no cure.
The outbreak in Angola began last year in the northern province of Uige. The health
minister says there were two hundred fifty-two cases. He says only twenty-five people,
or ten percent, survived.
The World Health Organization had earlier estimates of more than three hundred deaths.
Still, this was the worst outbreak recorded since laboratories first identified the Marburg
virus in nineteen sixty-seven.
SCIENCE IN THE NEWS was written by Jerilyn Watson and Caty Weaver. Cynthia
Kirk was our producer. I'm Bob Doughty.
And I'm Pat Bodnar.
Internet users can read and listen to our programs at
voaspecialenglish.com. Join us next week for more news about science in Special
English on the Voice of America.
6