Draft:Carolyn Napoli

• Comment: See WP:MOS. Ratnahastin (talk) 05:08, 20 May 2024 (UTC)

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Carolyn Napoli is an Emerita Research Professor, University of Arizona. Over the span of her forty-plus year career, she made contributions in the disciplines of plant molecular biology, plant genomics, bioinformatics, and most notably, in the field of epigenetics. In 1990 she co-discovered the mechanism of co-suppression., gene silencing which, like transposon silencing, was first discovered in plants.

Early Life and education

Napoli was born Carolyn Ann Cole in Harlingen, Texas on April 29,1946. At age 19, she married, had a daughter, divorced, then as a single mother, completed her Associate of Arts degree at a local community college, after which she transferred to the University of Florida. There, she received a scholarship which enabled her to pursue a Bachelors of Sciences degree in microbiology which she obtained with honors in 1972. While still an undergraduate, she secured a position in David H. Hubbell’s laboratory in the Soil Sciences Department.

Research and career

Continuing in the Hubbell lab, Napoli pursued her PhD research investigating the process of infection of Trifolium (clover) roots by the soil bacterium, Rhizobium trifolii. Using electron microscopy, she demonstrated, for the first time, the development of infection threads within root hairs. She also showed that root exudates can promote a more rapid formation of infection threads in root hairs, implying the existence of a signal that stimulates the Rhizobium-root hair interaction. As root hairs are the specific site of rhizobial infection, her analysis of carbohydrate profiles from root hairs and epidermal cells revealed differences in cell wall composition and led to insight as to why root hairs were the infection target.

Supported by an National Science Foundation (NSF) postdoctoral fellowship, Napoli continued her Rhizobium research in the laboratory of Peter Albersheim at the University of Colorado Boulder later joining the lab of Larry Gold in the Department of Molecular, Cellular and Developmental Biology. Inspired by the 1961 experiment that led to the iconic “The General Nature of the Genetic Code for Proteins” publication, Napoli embarked on a set of experiments exploring how RNA synthesis is reinitiated in bacteriophage T4. She tested this hypothesis by way of DNA sequencing and poly-acrylamide gel electrophoresis of truncated proteins and confirmed translational reinitiation occurred at specific sites.

Transitioning from academia, Napoli tested the waters of the rapidly expanding biotechnology industry, accepting a position at the International Plant Research Institute (IPRI) in San Carlos, California, where she met Brian Staskawicz. When Staskawicz subsequently took on a faculty position at the University of California, Berkeley, he offered Napoli a position in his new lab, working on plant avirulence genes

At this juncture, she met and later married Richard A. Jorgensen, who was working in Oakland at the agricultural biotechnology company Advanced Genetic Sciences, Inc. (AGS) which was acquired later by DNA Plant Technology Corporation. Together at AGS, they established a program to engineer floriculture crops. Their primary focus was on engineering flower petal pigmentation in high-value crops such as carnation, chrysanthemum and rose. For proof of principle, they chose petunia as a model system, because a plant transformation method existed for petunia and because the anthocyanin pathway responsible for flower color was well characterized in petunia. With a goal of increasing flower pigmentation by overexpressing the gene encoding the Chalcone Synthase (CHS) they deployed a vector for high-level translation designed by their AGS colleague Jonathan Jones. Although their hypothesis was that the sense CHS over-expression construct would intensify flower color, they were surprised to see that the flowers were completely white in some transformants and produced developmentally controlled white-on-purple patterns in others. The antisense CHS construct created a completely different effect with irregular, lighter petal pigmentation. Beyond the novel pigmentation patterns, including one dubbed “Cossack Dancer,” the distinctive image of which was featured in The Plant Cell 30-year retrospective, "Refections on Plant Cell Classics," and inspired the creation a the petunia-themed earrings. Napoli and Jorgensen had identified a mechanism they coined “co-suppression.”. This identification of post transcriptional gene silencing predated the discovery of RNA interference (RNAi) and contributed to the current understanding of the commonality of RNA-mediated gene silencing in eukaryotes.

From DNAP, Napoli accepted a faculty position in the Department of Environmental Horticulture at the University of California, Davis (UCD) and Jorgensen joined her Environmental Horticulture Department. Upon her arrival at UCD, she begin pursuing ethyl methanesulfonate (EMS) to produce mutations in both petunia and Arabidopsis seeds. By screening over 1,200 mutants in petunia she identified a certain bushy phenotype that she termed decreased apical dominance (dad) mutants and subsequently published her analysis in the journal Plant Physiology of the reversal of this phenomenon by grafting. In a subsequent collaboration with Loverine Taylor, Napoli identified a phenotype that could be used as a selectable marker for plant breeding research.

Napoli and Jorgensen then transferred their research grants to the Department of Plant Sciences at the University of Arizona (UA). At UA Napoli focused on designing and distributing resources to the Arabidopsis and maize research communities under the auspices of an NSF Plant Genome Research Program grant led by Jorgensen and Vicki Chandler.

In addition, during her time at UA, Napoli became the primary driver in launching the NSF-funded ChromDB (Chromatin Database), a platform for displaying chromatin-associated proteins, including RNAi-associated proteins, for a range of organisms. ChromDB provided high school teachers with hands-on bioinformatics and functional genomics experiences, filling a gap for those seeking Science, technology, engineering and math (STEM) careers, particularly those students traditionally underrepresented in the biotechnology workforce.

Personal Life

Napoli is married to co-suppression co-inventor Richard A. Jorgensen. In retirement, they moved to Guanajuato, Mexico. Her daughter, Anne-Marie Napoli, is co-owner (with partner Ethan Summers) and managing director at Almost Human Media in Santa Cruz, Calif. They have a son Zeke, Carolyn Napoli’s grandson.

Awards and honors

In 2023 Napoli was recognized as a Pioneer Member of the American Society of Plant Biologists.