Alanna Cohen successfully defended her PhD thesis “Genomic resources for the study of Anisogramma anomala and the Eastern Filbert Blight pathosystem” on 16 December 2024. Members of her committee were: Brad Hillman (advisor), Don Kobayashi, Ning Zhang and Tom Molnar. Brad Hillman was the Waksman Honorary Lecturer at the Theobald Smith Society 2016 Spring Symposium. He retired in June 2024 and Alanna was his final PhD student. Alanna was an invited speaker at our 2023 Spring Symposium.
Alanna has been an outstanding student and an active bioscience researcher since her undergraduate days at The College of New Jersey. She was on the Dean’s List for seven of her eight undergrad semesters and a member of the Beta Beta Beta Biological Honors Society for all four undergrad years. She won a summer scholarship to Cornell’s Microbial Friends & Foes Research Experience for non-Cornell Undergraduates in 2014 where she became interested in plant pathology. There she worked with Professor Barbara Gillian Turgeon studying virulence factors and loss of function mutations in Northern Corn Leaf Blight (Setosphaeria turcicum) and Southern Corn Leaf Blight (Cochliobolus heterostrophus). All four years at TCNJ she worked in Professor Wendy Clement’s lab studying the phylogenetics of Ficus and Viburnum evolution, culminating in her first peer reviewed publication (1).
Alanna quickly established herself in the Microbial Biology Graduate Program by winning the School of Environmental & Biological Sciences Excellence Fellowship in her first year and the Hachnasarian Award in her second year for top academic performance based on her Comprehensive Exam score, course grades, and lab rotation performance.
She chose an especially challenging pathogen to study for her doctoral work. The ascomycete fungus Anisogramma anomala causes Eastern Filbert Blight on hazelnut trees. The pathogen basically only grows on living host tissue; it cannot be readily cultured. While its ascospores germinate in complex media, only very small colonies result after months of growth yielding very little biomass for nucleic acid extraction. So, studying A. anomala is to say the least, challenging. Despite this formidable obstacle, Alanna was able to tediously grow enough biomass to extract enough DNA to sequence, assemble, annotate and characterize two high quality genome assemblies of two strains of A. anomala. She used the data to propose mechanisms which the fungus adapts to overcome resistance through compatible resistance gene mechanisms (2). Professor Dana Price, the 2023 Theobald Smith Young Investigator Awardee, was instrumental in showing Alanna the bioinformatics ropes. He trained her so well; she now teaches a grad level bioinformatics course.
For population studies, culturing the A. anomala was out of the question. Alanna developed a protocol to extract DNA directly from perithecia (spore-bearing structures) embedded in the hazelnut tissue. This allowed her to genetically fingerprint over 300 isolates to complete statistical analysis to demonstrate the genetic shift in populations of A. anomala that result in differential resistance gene interactions with hazelnut (A.B. Cohen, B.I. Hillman, T.J. Molnar, unpublished manuscript)
Residency in Brad Hillman’s lab would not be complete without a solid background in mycoviruses (3‑5). Brad has studied the viruses due to the ability of some to reduce the virulence of their host and thus act as potential biocontrol against Cryphonectria parasitica (chestnut blight) which virtually wiped out the American chestnut population. Alanna mentored several undergraduate students in Brad’s lab characterizing mycovirus isolates from C. parasitica as well as virus discovery as a means for biological control in dollarspot (Clarireedia spp.), the fungal turfgrass pathogen.
Alanna has always had a strong desire to teach. She honed her teaching skills (in tandem with her laboratory research skills) as a Teaching Assistant for Microbiology for the Health Sciences. After two years, she became the Head Teaching Assistant for the course and in 2022, she ended up teaching the entire course as an Adjunct Assistant Professor. With the departure of Professor Yana Bromberg to Emory University in 2023, Alanna stepped in as an Adjunct Assistant Professor to teach Bromberg’s graduate level Bioinformatics course (Dept. of Plant Biology). She will continue to teach the course this semester.
Dr Cohen is now working in Anat Kreimer’s Lab at Rutgers Center for Advanced Biotechnology and Medicine.
1. Clement, WL, Bruun-Lund, S, Cohen, A, Kjellberg, F, Weiblen, GD, Rønsted, N. 2020. Evolution and classification of figs Ficus, Moraceae) and their close relatives (Castilleae) united by involucral bracts. Botanical Journal of the Linnaen Society 193:316–339. https://doi.org/10.1093/botlinnean/boaa022
2. Cohen, AB, Cai, G, Price, DC, Molnar, TJ, Zhang, N, Hillman, BI. 2024. The massive 340 megabase genome of Anisogramma anomala, a biotrophic ascomycete that causes eastern filbert blight of hazelnut. BMC Genomics 25:347. https://pubmed.ncbi.nlm.nih.gov/38580927
3. Hillman, BI, Cohen, AB. 2021. Mitoviruses (Mitoviridae), p. 601–606. In Bamford, DH, Zuckerman, M (ed), Encyclodepia of Virology, 4th ed. Elsevier Ltd., Amsterdam. https://www.sciencedirect.com/science/article/abs/pii/B9780128096338213241
4. Hillman, BI, Cohen, AB. 2021. Mycoreoviruses (Reoviridae), p. 607–614. In Bamford, DH, Zuckerman, M (ed), Encyclodepia of Virology, Elsevier Ltd., Amsterdam. https://www.sciencedirect.com/science/article/abs/pii/B9780128096338213265
5. Hillman, BI, Cohen, AB. 2021. Totiviruses (Totiviridae), p. 648–657. In Bamford, DH, Zuckerman, M (ed), Encyclodepia of Virology, 4th ed. Elsevier Ltd., Amsterdam. https://www.sciencedirect.com/science/article/abs/pii/B9780128096338213472
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