Page 11 - Dad's St Jude Projecy

Early days (1963-1968)

By David Kingsbury

I knew about Allan Granoff long before I ever hoped to meet him. He
was a legend at Yale Medical School when I was a student there in
the late 1950's. He was one of the pioneers of animal virus genetics,
applying the quantitative approaches that had brought such power
to the work of the bacteriophage group, inspired by the great Max

Delbriick. Working at the Public Health Research Institute of New
York with George Hirst, Allan's quantitative approach had
uncovered a great mystery. Genetic recombination ( the
reassortment of genes of two parents among the offspring) occurs

at a high rate in people, animals, and plants, and the phage group
had demonstrated frequent genetic recombination in their bacterial
viruses. Moreover, in the early 1950's, Macfarlane Burnet had
observed many recombinants in crosses between different strains of
influenza viruses. So, it was natural to assume that the mechanisms

of genetic recombination (whatever they might be), would be
universal among all organisms.

Unfortunately, influenza virus didn't lend itself to the quantitative
analyses that Allan had to perform, so he began studying a related

virus, Newcastle disease virus (NDV, a pathogen of fowl that's
related to mumps and measles viruses.) However, the experiments
didn't work with NDV. No matter how closely he looked, Allan didn't
find any genetic recombination. But he had to be believed, because

he had done everything so thoughtfully and thoroughly. Allan made
his scientific mark with this discovery. In due course, answers to the
mystery were discovered through molecular biology, as I and others
found that all of the genes ofNDV are linked together in a single
strand of nucleic acid - a single chromosome.

Then Marcel Pons and others showed that the genes of influenza
viruses are unlinked, residing mainly in separate chromosomes, so
when a cell is infected by two strains of influenza virus, the
chromosomes of each virus mingle freely, and are randomly
withdrawn into progeny viruses. As the chromosomes reassort, so