Kari Lenhart, PhD

Kari Lenhart, PhD

Assistant Professor
Co-Director, Graduate Biology Program
Department of Biology
Office: PISB 420
kari.f.lenhart@drexel.edu
Phone: 215.895.6772

Additional Sites:

lenhartlab.com


Education:

  • Post-Doc, University of Pennsylvania
  • PhD, Princeton University
  • BS, Ursinus College

Research Interests:

Stem cells are critical for maintenance of adult tissues, with defects in stem cell behavior leading to cancer and tissue degeneration. Yet many aspects of stem cell regulation are still poorly understood. In particular, how the stem cell specialized environment, or niche, is capable of controlling and coordinating multiple different types of stem cells within the same tissue remains largely unknown. In my lab, we study the simplified, easily accessible stem cell system of the Drosophila fruit fly testis to better understand niche-stem cell and stem cell-stem cell interactions. The fly testis, just like the mammalian testis, contains two different cell types- germ cells that will eventually become sperm and somatic cells that support the germline within the niche and as germ cell differentiate. Our lab has identified critical roles for these somatic cells in controlling multiple aspects of germline cell biology. Not only is the soma required during homeostasis to promote proper functioning of the tissue, but it is also essential to control tissue regeneration during stress and disease.

The lab uses genetics and long-term live imaging to address:

  1. How do somatic stem cells control germline stem cell (GSC) biology?
  2. How do somatic cells regulate restoration of GSCs following stress?
  3. How are soma-germline interactions disrupted during tumorigenesis? During aging?
  4. How do somatic cells differ between the testis and ovary? How are these differences maintained over time? What impact do these differences have on the associated germline?

Studying each of these questions will provide critical insight into how the niche controls stem cell behavior which may have important implications for stem cell therapies, cancer treatments and ameliorating the effects of aging.

Selected Publications:

  • Roach TV, Harsh S, Sainath R, Bach EA, and Lenhart KF. Conversion of somatic sex identity in the testis induces female-specific cellular behaviors in the soma and early oocyte specification in the germline. bioRxiv. 2024.
  • Roach TV and Lenhart KF. Mating-induced Ecdysone in the testis disrupts soma-germline contacts and stem cell cytokinesis. Development. 2024.
  • Lenhart KF, Capozzoli B and DiNardo S. Failure of stem cell cytokinesis with age due to diminished JAK/Stat activity. Current Biology. 2019.
  • Lenhart KF and DiNardo S. Somatic cell encystment promotes abscission in germline stem cells following a regulated block in cytokinesis. Developmental Cell. 2015.