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Guest post by Nina Wolff pays tribute to long-standing GSA member Margaret Lieb.

Margaret (Peggy) Lieb died on March 8, 2018 in South Pasadena, California at the age of 94. After attending schools in New Rochelle, NY, she graduated magna cum laude from Smith College, and subsequently studied with  H.J. Muller at Indiana University and with Francis Ryan at Columbia University, where she received her PhD degree. Following postdoctoral studies at Caltech in the laboratory of Max Delbruck, and in Paris at the Pasteur and Radium Institutes, Lieb taught at Brandeis University and then moved to the Medical School of the University of Southern California where she continued her research and teaching for 45 years. After her retirement, she continued to be active as an Emerita member of the faculty, and as a garden docent at the Huntington Museum and Botanical Garden.

While at Caltech, Lieb published one of the first studies of phage lambda, and subsequently isolated and characterized a large number of mutations in the repressor gene of the phage. Her studies of lysogenization indicated that the active repressor was a dimer, a conclusion later confirmed by biochemical studies in other laboratories. While mapping mutations in the lambda repressor gene, she observed that excess recombination (negative interference) was associated with mutations arising from the deamination of 5-methylcytosine. This led to the identification of a novel mismatch repair gene (vsr) in E. coli – a gene that is adjacent to the gene for cytosine methylase. The Vsr function reduces the probability of mutations that occur due to spontaneous deamination of 5meC. Although genes related to vsr appear to be limited to bacteria, the search for genes like vsr in eukaryotes, where 5-methycytosine has important regulatory functions, has led others to the discovery of additional specific repair activities in higher organisms.

In 1972-1973, Lieb served as Program Directory of the Genetic Biology program of the National Science Foundation. She was elected Chairman of the Virology Division of the ASM in 1975, and served on the editorial boards of Journal of Virology and GENE. She was a Fellow of the American Association for the Advancement of Science (AAAS).

Peggy Lieb maintained an active interest in the research of her colleagues, and will also be missed by the students and post-doctoral fellows who spent time in her lab. Her high standards of performance in the classroom and in the lab were challenging and also appreciated by those who knew her.

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