Mendel, Austrian botanist and monk, proposes basic laws
of heredity, based on crossbreeding experiments with
pea plants. However this great discovery was ignored
for more than 30 years.
embryologist Walther Fleming spots tiny threads within
the cells' nuclei that appear to be dividing, while
examining a salamander larvae under a microscope. The
threads later turn out to be chromosomes.
Biologist Thomas Hunt Morgan reveals that some genetically
determined traits are sex linked by experiments with
fruit flies. His work also confirms that the genes determining
these traits reside on chromosomes.
Muller, an American biologist discovers that X rays
can cause genetic mutations in fruit flies.
Avery and Maclyn McCarty prove that DNA, not protein,
is the hereditary material in most living organisms
by experiments using pneumococcus bacteria.
biochemist James Watson and British biophysicist Francis
Crick propose the discovery of the double-helix structure
of DNA, the molecule that carries the genetic code.
geneticist Charles Yanofsky and his colleagues prove
that the sequence of nucleotides in DNA corresponds
exactly to the sequence of amino acid s in proteins.
of University of Wisconsin synthesize the first gene
biochemists Stanley Cohen and Herbert Boyer insert a
gene from an African clawed toad into bacterial DNA,
in which its functions appeared. This was the beginning
of genetic engineering.
an international meeting in Asilomar, California, scientists
call for guidelines for recombinant-DNA research.
first genetic engineering company, Genetech, is founded
in South San Francisco.
from Genetech and a medical center of Duarte, California,
successfully clone the gene for human insulin.
introduce a human gene that codes for the protein interferon,
into a bacterium.
Cline and his coworkers create a transgenic mouse, transferring
the functional genes of an animal to another.
U.S. Food and Drug Administration approves the first
genetically engineered drug, a form of human insulin
produced by bacteria.
locate a genetic marker for Huntington's disease on
chromosome 4. Their achievement leads to a screening
test, but the disorder remains incurable. The gene itself
is found 10 years later.
Mullis, a biochemist at Cetus Corp., conceives of
the so-called polymerase cahin reaction, or PCR, a
technique that will enable scientists to rapidly reproduce
tiny snippets of DNA while driving along a California
Jeffreys of Britain's University of Leicester, develops
"genetic fingerprinting," a technique used to identify
individuals from one's unique sequences of DNA.
use of genetic fingerprinting in a criminal investigation.
FDA approves the first genetically engineered vaccine
for humans, hepatitis B.
University receives the first patent for a genetically
altered animal, a mouse highly susceptible to breast
National Center for Human Genome Research is founded,
headed by James Watson. It presently oversees the $3
billion U.S. effort to map and sequence all human DNA
by 2005 (the Human Genome Project).
launch of the International Human Genome Project.
French Anderson, an American geneticist performs the
first gene therapy to a four year old girl with an immune-system
disorder called ADA deficiency.
King of the University of California, Berkeley, finds
evidence that a gene on chromosome 17 causes the inherited
form of breast cancer and also increases the risk of
ovarian cancer, by analyzing chromosomes from women
in cancer-prone families.
U.S. Army begins collecting blood and tissue samples
from all new recruits as part of a "genetic dog tag"
program, aimed for better identification of soldiers
killed in combat.
and British scientists unveil a technique for testing
embryos in vitro for genetic disorders such as cystic
fibrosis and hemophilia.
at the U.S. National Cancer Institute report that at
least one gene related to homosexuality resides on the
X chromosome, which is inherited from the mother, by
analyzing the family trees of gay men and the DNA of
pairs of homosexual brothers.
Washington University researchers clone human embryos
and nurture them in Petri dish for several days. The
project provokes protests from ethical politicians and
critics of genetic engineering.
international research team of the Center for the Study
of Human Polymorphisms in Paris, led by Daniel Cohen,
produces a rough map of all 23 pairs of human chromosomes.
at Duke University Medical Center in Durham, North Carolina
report that they have transplanted hearts from genetically
altered pigs into baboons. All three transgenic hearts
survived at least a few hours, proving cross-species
operations to be possible.
at Scotland's Roslin Institute, led by embryologist
Ian Wilmut, report that they have cloned a sheep named
Dolly from the cell of an adult ewe.
of the University of Hawaii, clone a mouse using a variation
of Wilmut's technique, creating not only dozens of copies
but three generations of cloned clones.
research teams succeed in growing embryonic stem cells.
at Japan's Kinki University clone eight identical
calves using cells taken from a single adult cow.