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Mariana Wolfner

Mariana Wolfner

Stephen H. Weiss Presidential Fellow

423 Biotechnology
(607) 254-4801

Mariana Federica Wolfner is the Goldwin Smith Professor of Molecular Biology and Genetics, and a Stephen H. Weiss fellow. Her research focuses on understanding, at the molecular/gene level, the important reproductive processes that occur around the time when a sperm fertilizes an egg. Using the Drosophila model, the Wolfner laboratory studies the molecular signals that "activate" an oocyte to begin embryo development and also studies how seminal proteins modulate the reproductive physiology and behavior of female insects. Mariana’s primary teaching areas are in Development & Evolution, and Developmental Genetics. Mariana has a B.A. in Biology and Chemistry from Cornell, a Ph.D. in Biochemistry from Stanford, and she did postdoctoral work at UC San Diego. She is a Fellow of the American Association for the Advancement of Science, and has received awards and recognition for her research, teaching and advising. She serves on several Editorial and Biology-organizations’ Boards, and on various Study Sections and grants panels. For further information about the Wolfner lab’s research, please see:

Research Focus

Our lab uses molecular biology and genetics to dissect the important reproductive processes that occur around the time when a sperm fertilizes an egg. We use the fruit fly, Drosophila melanogaster, for most of our work. Drosophila reproduction and development can be readily studied with molecular biology, genetic and genomic techniques. Furthermore, Drosophila serves as a model for other animal systems. Many of the genes and reproductive/developmental phenomena in flies have counterparts or analogues in other animals, including humans and insect vectors of disease.
In one project we focus on the actions of seminal proteins that female flies receive from the males with which they mate. These proteins modify the behavior and reproductive physiology of the mated female. For example, they increase the female’s egg-production, make the female less likely to mate again, affect her feeding and sleep behaviors and her longevity, and cause her to store and maintain sperm that she received in the mating. We aim to understand at the molecular level how these male proteins cause changes in females. We know the suite of ~200 seminal proteins and have identified ones that induce specific post-mating responses. We study how they act through neurological or molecular pathways, or by binding to female or sperm proteins. In collaboration with our colleague Andy Clark we examine the regulators of sperm competition, a process related to the action of seminal proteins. We also aim to apply our research on Drosophila seminal proteins to the understanding of reproduction of insect vectors of disease. We are doing this by studying Aedes mosquitoes, in collaboration with our colleague Laura Harrington.

We also wish to discover the molecular signals that “activate” an oocyte to initiate embryo development. An activated egg completes meiosis, fuses its genetic material with that of the sperm, and begins the mitotic (cleavage) divisions. Although in many organisms the trigger for egg activation is fertilization, in insects egg activation is triggered by passage through the female’s reproductive tract. With T. Aigaki (Tokyo Metro U.) we showed that calcium enters the egg during this process, and a wave of increased calcium then traverses the activating egg. Using genetics and proteomics we are identifying conserved proteins that are essential for the transition from egg-to-embryo, including several that modulate transcriptome dynamics during this process.

For details about the lab and our research please visit:

Outreach and Extension Focus

Although I have no formal extension responsibilities, I carry out extension activities, including presentations to teachers, K-12 students, and other members of the lay public, providing Drosophila strains to local teachers and photographs of Drosophila reproductive structures to a museum, etc.

Teaching Focus

I consider teaching and mentoring – in classes, in the research lab, and through informal interactions – to be a very important way in which I can also contribute professionally (and, I love it!). My goal is to transmit to students the latest exciting findings in biology, the ability to read and critique the scientific literature, and the joy in uncovering and interrelating biological concepts. I strive to interact with each students as an individual, whether in the classroom, lab, or in informal interactions.

Classroom teaching:
I currently teach:
Development and Evolution (BioMG4610)
Developmental Genetics (BioMG6780)

I also participate in, and sometimes co-organize, several team-taught courses in Genetics, Genomics & Development or in Biochemistry, Molecular and Cell Biology, and guest-lecture in several other courses each year.
Because I enjoy thinking, learning and teaching about approaches and findings at the intersection between fields, I’ve co-taught interdisciplinary courses like genomics of non-model organisms, sperm storage patterns, evo-devo, molecular neurobiology. I played a central role in the redesign of Cornell’s biology major curriculum, and developed and taught several previous courses including: Advanced Developmental Biology, Fertilization and the Early Embryo, and special-topics courses in genetics, developmental, or molecular biology.

One-on-one, in-laboratory research-mentoring:
I consider individualized one-on-one teaching/mentoring in the laboratory to be as important as my classroom teaching. My lab includes undergraduate and graduate students, postdoctoral fellows, and staff; ~10-15 researchers in total. As their mentor I work to be a supportive, informed, and enthusiastic guide and collaborator, as we together come up with interesting questions and craft ways to address those, critique results, and work on skills like scientific presentations, etc.

Informal interactions:
I love to chat about any aspect of biology, and biology careers, at programs in the residence halls, with students before/after class, at Biology open-houses, or during chance encounters on campus or at meetings.

Awards and Honors

  • Goldwin Smith Professor of Molecular Biology & Genetics (2013) Cornell University
  • elected Vice-Chair (2015), then Chair (2017) GRC on Fertilization & Activation of Devt. (2017) Gordon Research Conferences
  • Distinguished Lecture (2012) Huck Institute, Penn State Univ.
  • Kendall S. Carpenter Memorial Award for Distinguished Advising (2012) Cornell University
  • Lady Davis Fellow (2010) Hebrew University of Jerusalem, Israel