VOICE ONE:
This week —— news about a genetic map (遗传学图) that is being called a powerful new tool for medical research …… Then, a report on an ancient Christian (基督教的) church found under an Israeli prison ……And Angola says a recent outbreak (爆发) of Marburg virus is over.
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VOICE ONE:
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 (单模标本).
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 (deoxyribonucleic acid 脱氧核糖核酸) differences before they finish.
VOICE TWO:
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 (治疗). People could also learn if they have an increased risk (风险) of a disease because of their genes.
In some cases, such knowledge might lead to preventive (预防性的) 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 (阿兹海默症), 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. The work involves researchers from Britain, Canada, China, Japan, Nigeria (尼日利亚) and the United States.
VOICE ONE:
The new map is based on DNA from two hundred sixty-nine people. They represent four ethnic groups: European, Japanese, Chinese and Yoruba ((非洲)约鲁巴).
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 (马萨诸塞州). Another project director, Peter Donnelly, is from Oxford University (牛津大学) 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 (基因) 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 (癌).
VOICE TWO:
The HapMap Project developed from information provided by the Human Genome Project. That project was completed in two thousand three. It identified (鉴别) all the chemical pieces in DNA, the genetic material in cells.
DNA has more than three thousand million building blocks. A series of (一系列) 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 (单核苷酸多态性) can happen. The HapMap Project is identifying common places where they are found.
VOICE ONE:
Studying haplotype blocks will make it easier to find the genes suspected of (怀疑) causing a disease. The researchers may be able to investigate (调查) which blocks of DNA are common among people with the same disease. The process would be much faster than examining every piece of DNA.
Stacey Gabriel of the Broad Institute says mapping just one SNP used to cost almost a dollar per patient (患者). Today, she says, it often costs less than one cent. In the past, it was possible to test only one hundred genotypes (基因型) 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 (效力) of this method. But several studies already have been published using the new information.
For example, scientists at Yale University in New Haven, Connecticut (康涅狄格), used the HapMap to connect a gene to macular degeneration (恶化). That is a leading cause of blindness in older people.
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VOICE TWO:
Palestinians in a prison in Israel have found the ruins of an ancient Christian place of worship. Some archaeologists (考古学家) 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 suggested.
The prison is in Megiddo. Israeli officials had ordered a dig to search for ancient objects before a planned addition to the prison