![]() ![]() This time, however hundreds of other investigators were also racing to publishĭetailed descriptions of every new disease gene found. Collins wasn't the only researcher actively "gene hunting" at TheĪccomplishments were a result of both cutting-edge cloning techniques like Himself by discovering the location of three important disease genes-those responsibleįor cystic fibrosis, Duchenne muscular dystrophy, and Huntington's disease. Indeed, with the advent of Maxam-Gilbert DNA sequencing in the mid-1970s (Maxam & Gilbert, 1977), it actually became possible to read the entire sequence of a cloned gene, perhaps 1,000 to 30,000 base pairs long, with relative ease.Īdvances, mapping of important disease genes was all the rage by the 1980s, andįrancis Collins was one of the masters of this process. With these tools in place, the recombinant DNA age was about to allow scientists to start cloning genes en masse for the first time. Then, during the late 1960s and early 1970s, the combined work of several groups of researchers culminated in the isolation of proteins from prokaryotes using DNA cut at specific sites and spliced with DNA from other species (Meselson & Yuan, 1968 Jackson et al., 1972 Cohen et al., 1973). Nonetheless, although it was well established by this time that DNA was the heredity material and that each nucleus must contain the complete DNA required to instruct the chemical processes of an organism, the details of reading individual gene sequences, let alone whole genomes, were out of the technical grasp of scientists.Ī large part of the reason for this inability to read gene sequences was the fact that there were simply very few sequences available to read furthermore, the tools required to identify, isolate, and manipulate desired stretches of DNA were just evolving. Next, the 1961 discovery of mRNA (Jacob & Monod, 1964) and the 1966 cracking of the genetic code (Figure 1 Nirenberg et al., 1966) made it possible to predict protein sequences based on DNA sequence alone. By 1959, Jerome Lejeune had demonstrated that Down syndrome was linked to chromosomal abnormalities (Lejeune et al., 1959). In 1952, Alfred Hershey and Martha Chase proved that DNA was the molecule of heredity, and shortly thereafter, Watson, Crick, Franklin, and Wilkins solved the three-dimensional structure of DNA. ![]() ![]() However, this began to change during the 1950s with the birth of modern molecular genetics. Before the middle of the twentieth century, the gene was an abstract concept thought to physically resemble a "bead on a string," and within the scientific community, it was accepted that each gene was associated with a single protein, enzyme, or metabolic disorder. ![]()
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