Alexandra (Alex) Z. Worden (born 1970) is a microbial ecologist and genome scientist known for her expertise in the ecology and evolution of ocean microbes and their influence on global biogeochemical cycles.
Her early exposure to engineering came through computer programming at BBN Technologies before attending university and with the Massachusetts Institute of Technology solar electric car project. At the time, the award winning MIT Solar Electric Vehicle Team[3] included several individuals who then became leading innovators in the tech world, including Gill Pratt[4] and Megan Smith, and the team was founded by Worden's brother, James Worden.[5][6][7]
Worden's early awards came from NASA Earth Systems Science Graduate Fellowship and University of Georgia Regents Award as a graduate student. In 2000 she received a US National Science Foundation Microbial Biology Postdoctoral Fellowship in support of her groundbreaking research on picoeukaryotes. Upon founding her lab in 2004 she was awarded a Young Investigator Award.[9]
Worden is a proponent of STEM education and innovation and has highlighted the need for relevant "...role models to inspire greater diversity and creativity" in science.[17]
Research
Worden's research focuses on the physiology and ecology of eukaryotic phytoplankton and their roles in the carbon cycle.[18][19] She initiated this research through an NSF Postdoctoral Fellowship in Microbial Biology and expanded it thereafter by adapting multiple molecular and omic methods to characterize the evolution and ecological contributions of these photosynthetic plankton, which are now known to be major ocean primary producers.[20][21] At Scripps Institution of Oceanography, a different research pursuit on microbial interactions, while in the laboratory of Farooq Azam, led to her work that overturned the idea that Vibrio cholerae existed primarily attached to copepods in aquatic systems.[22] This was considered important for understanding the ecology of this human pathogen and vectors for transmission of infective cells. During this period she and Azam introduced the concept of Ecosystems Biology (also spelled Eco-systems Biology, EcoSystems Biology or (Eco)-systems Biology), coining the term in a 2004 perspective.[23] The concept was embraced by the scientific community in several later perspectives,[24][25] and is being pursued by human microbiome-biologist Jeroen Raes and microbial oceanographer Edward DeLong. A Jacques Monod conference on Marine Eco-Systems Biology was initiated in 2015.[26]
Worden helped pioneer "targeted metagenomics"[27][28][29] wherein cells of particular interest are separated from the masses using flow cytometry (on a ship) and genomes are then sequenced from only the cells of greatest interest. Using this approach Worden and collaborators at the DOEJoint Genome Institute sequenced partial genomes from a key group of uncultured eukaryotic algae whilst showing the distribution of these photosynthetic protists in the ocean. Most recently, her lab adapted these approaches to study uncultured unicellular predators in the ocean, and discovered giant viruses that infect Choanoflagellates, a widespread predator group related to animals. Remarkably, the viruses bring to the non-photosynthetic, predatory host complete bacteriorhodopsin-like photosystems that pump protons. The authors also highlighted the importance of understanding the cell biological role of the viral rhodopsin photosystem in infected hosts[30]
Her laboratory also investigates ancestral components of land plants,[31] evolutionary biology and distributions of uncultured taxa[32][33] and interactions between viruses and phytoplankton host cells. In 2015, she and co-authors called for a "rethinking of the marine carbon cycle".[34] Worden publishes in the fields of environmental microbiology, evolutionary biology, genome science and oceanography.
^Cuvelier, Marie L.; Allen, Andrew E.; Monier, Adam; McCrow, John P.; Messié, Monique; Tringe, Susannah G.; Woyke, Tanja; Welsh, Rory M.; Ishoey, Thomas; Lee, Jae-Hyeok; Binder, Brian J.; DuPont, Chris L.; Latasa, Mikel; Guigand, Cédric; Buck, Kurt R.; Hilton, Jason; Thiagarajan, Mathangi; Caler, Elisabet; Read, Betsy; Lasken, Roger S.; Chavez, Francisco P.; Worden, Alexandra Z. (August 17, 2010). "Targeted metagenomics and ecology of globally important uncultured eukaryotic phytoplankton". Proceedings of the National Academy of Sciences of the United States of America. 107 (33): 14679–14684. Bibcode:2010PNAS..10714679C. doi:10.1073/pnas.1001665107. PMC2930470. PMID20668244.
^Needham, David M.; Yoshizawa, Susumu; Hosaka, Toshiaki; Poirier, Camille; Choi, Chang Jae; Hehenberger, Elisabeth; Irwin, Nicholas A. T.; Wilken, Susanne; Yung, Cheuk-Man; Bachy, Charles; Kurihara, Rika; Nakajima, Yu; Kojima, Keiichi; Kimura-Someya, Tomomi; Leonard, Guy; Malmstrom, Rex R.; Mende, Daniel R.; Olson, Daniel K.; Sudo, Yuki; Sudek, Sebastian; Richards, Thomas A.; Delong, Edward F.; Keeling, Patrick J.; Santoro, Alyson E.; Shirouzu, Mikako; Iwasaki, Wataru; Worden, Alexandra Z. (October 8, 2019). "A distinct lineage of giant viruses brings a rhodopsin photosystem to unicellular marine predators". Proceedings of the National Academy of Sciences. 116 (41): 20574–20583. Bibcode:2019PNAS..11620574N. doi:10.1073/pnas.1907517116. PMC6789865. PMID31548428.