Chapter 1 Why Gene Cloning and DNA Analysis are Important 1.1 The early development of genetics 1.2 The advent of gene cloning and the polymerase chain reaction 1.3 What is gene cloning? 1.4 What is PCR? 1.5 Why gene cloning and PCR are so important 1.5.1 Obtaining a pure sample of a gene by cloning 1.5.2 PCR can also be used to purify a gene 1.6 How to find your way through this book
1.1 The early development of genetics Genes reside on chromosome was proposed by W. Sutton in 1903. T.H. Morgan developed gene mapping in 1922. Analysis of the relative positions of 2000 genes on the 4 chromosomes of Drosophila melanogaster. Walter Stanborough Sutton (April 5, 1877 - November 10, 1916) was an American geneticist and physician whose most significant contribution to present-day biology was his theory that the Mendelian laws of inheritance could be applied to chromosomes at the cellular level of living organisms. This is now known as the Boveri-Sutton chromosome theory. Thomas Hunt Morgan (September 25, 1866 – December 4, 1945) was an American evolutionary biologist, geneticist and embryologist and science author who won the Nobel Prize in Physiology or Medicine in 1933 for discoveries relating the role the chromosome plays in heredity.
Deoxyribonucleic acid (DNA) is the genetic material (1944-1952). In 1927 Nikolai Koltsov proposed that inherited traits would be inherited via a "giant hereditary molecule" made up of "two mirror strands that would replicate in a semi-conservative fashion using each strand as a template". In 1928, Frederick Griffith 格里夫茲 discovered that traits of the "smooth" form of Pneumococcus could be transferred to the "rough" form of the same bacteria by mixing killed "smooth" bacteria with the live "rough" form. This system provided the first clear suggestion that DNA carries genetic information—the Avery–MacLeod–McCarty experiment—when Oswald Avery, along with coworkers Colin MacLeod and Maclyn McCarty, identified DNA as the transforming principle in 1943. DNA's role in heredity was confirmed in 1952, when Alfred Hershey and Martha Chase in the Hershey–Chase experiment showed that DNA is the genetic material of the T2 phage. Streptococcus pneumoniae 肺炎鏈球菌 type II-R (rough) type III-S (smooth) Frederick Griffith
In 1953, James D. Watson and Francis Crick suggested what is now accepted as the first correct double-helix model of DNA structure. Genetic code, transcription, translation.
1.2 The advent of gene cloning and the polymerase chain reaction Recombinant DNA technology, genetic engineering, gene cloning.
Figure 1.1 The basic steps in gene cloning. 1.3 What is gene cloning?
Figure 1.2 The basic steps in the polymerase chain reaction (PCR). 1.4 What is PCR? Kary Mullis invented polymerase chain reaction (PCR) in 1985.
Figure 1.3 Cloning allows individual fragments of DNA to be purified. 1.5 Why gene cloning and PCR are so important 1.5.1 Obtaining a pure sample of a gene by cloning 1.5.2 PCR can also be used to purify a gene
Two limitations of PCR! The sequences of the annealing sites must be known. The length of DNA sequence.