Back to top

Mariana Wolfner

Mariana Wolfner

Stephen H. Weiss Presidential Fellow

423 Biotechnology
(607) 254-4801

Mariana Federica Wolfner is the Distinguished Professor of Arts and Sciences in Molecular Biology & Genetics, a Stephen H. Weiss Presidential Fellow, and currently an Associate Department Chair. 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 in Advanced 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. Mariana has been honored to receive awards and recognition for her research from the Genetics Society of America, the Entomological Society of America, the International Congress of Entomology Council, and awards from Cornell for her teaching and advising/mentoring. Mariana is member of the National Academy of Sciences and a Fellow of the American Association for the Advancement of Science. She serves on several Editorial and Biology-organizations’ Boards, and on various 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

Members of my lab and I enjoy participating in outreach to K-12 students, and their parents/guardians and teachers, including in annual "Expanding Your Horizons" workshops.

Teaching Focus

I love to work with students in the classroom or lab, together discussing the latest exciting findings, reading and critiquing the scientific literature, and uncovering and interrelating biological concepts.

My main classroom teaching is:
Development and Evolution (BioMG4610)
Genetic Analysis of Biological Pathways (BioMG6870; co-taught with M. Goldberg)

I also participate in, and sometimes co-organize, team-taught courses in Genetics, Genomics & Development or in Biochemistry, Molecular and Cell Biology, and guest-lecture in several other courses each year. I enjoy co-teaching in courses at the intersection between fields, and playing a central role in the redesign of Cornell's biology major curriculum.

In one-on-one teaching/mentoring of undergraduate and graduate students and postdocs in my lab, I try to be a supportive, informed, and enthusiastic guide and collaborator. Together we aim to come up with interesting questions and ways to address them critically, and to hone professional skills like scientific presentation.

I am always happy to chat with students informally about biology and biology careers at programs before/after class, or during get-togethers or chance-encounters on campus.

Awards and Honors

  • 2018 GSA Medal (2018) Genetics Society of America
  • 2017 Recognition Award in Physiology, Biochemistry and Toxicology (2017) Entomological Society of America
  • Al Downe Lecturer (2016) Queen’s University, Kinston, Canada
  • Goldwin Smith Professor of Molecular Biology & Genetics (2013) Cornell University
  • Kendall S. Carpenter Memorial Award for Distinguished Advising (2012) Cornell University