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Table 1.

MODEL ORGANISMS SEQUENCED

Date sequenced9

Species

Total bases"

7/28/1995

Haemophilis influenzae (bacterium)

1,830,138

10/30/1995

Mycoplasma genitalium (bacterium)

580,073

5/29/1997

Saccharomyces cerevisiae (yeast)

12,069,247

9/5/1997

Escherichia coli (bacterium)

4,639,221

11/20/1997

Bacillus subtillis (bacterium)

4,214,814

12/31/1998

Caenorhabditis elegans (round worm)

97,283,371 99,167,964c

3/24/2000

Drosophila melanogaster (fruit fly)

~137,000,000

12/14/2000

Arabidopsis thaliana (mustard plant)

~115,400,000

1/26/2001

Oryza sativa (rice)

~430,000,000

2/15/2001

Homo sapiens (human)

~3,200,000,000

aFirst publication date.

bData excludes organelles or plasmids. These numbers should not be taken as absolute. Scientists are confirming the sequences; several laboratories were involved in the sequencing of a particular organism and have slightly different numbers; and there are some strain variations. Data were obtained from the (NCBI) Web site. cThe first number was originally published, and the second is a correction as of June 2000.

to study its structure and function. In 1977 Drs. Walter Gilbert and Fred Sanger independently developed methods for the sequencing of DNA, for which they received the 1980 Nobel Prize along with Berg. Sanger's group in England was the first to completely sequence a genome, identifying all 5,386 bases of the bacterial virus <px174.

Another technological breakthrough occurred in 1985, when the polymerase chain reaction method was developed by Dr. Kary Mullis and colleagues at Cetus Corp. This team devised a method whereby minute samples of DNA can be multiplied a billion-fold for analysis. This technique, which has many applications in diverse fields of biology, is one of the most important scientific breakthroughs in gene analysis. Mullis received the Nobel Prize for this work in 1993.

At this time, however, DNA sequencing was still done by hand. At best, a researcher could manually sequence only a few hundred bases per day. To be able to sequence the human genome, machines would be needed that could sequence a million or more bases per day. In 1986 Leroy Hood developed the first generation of automated DNA sequencers, thereby dramatically increasing the speed with which bases could be sequenced. Thus, by the mid-1980s the stage was set.

With these new techniques, molecular biologists now felt that it might be feasible to sequence the entire human genome. The first serious discussions came in June 1985, when Robert Sinsheimer, chancellor of the University of California at Santa Cruz, called a meeting of leading scientists to discuss the possibility of sequencing the human genome. Sin-sheimer was inspired by the success of the Manhattan Project, which was the concerted effort of many physicists to develop atomic weapons during World War II. That project led to rapid development and a massive influx of funding for physicists. Sinsheimer wanted a "Manhattan Project" for molecular biology, to enhance and expand human genome research.

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