A photo of Tony De Falco.

Tony J. De Falco, PhD

  • Co-Director, Reproductive Sciences Center
  • Associate Professor, UC Department of Pediatrics
I investigate the role of blood vessels and the immune system in both gonad formation and organ homeostasis.
Tony J. De Falco, PhD



My research focuses on how the fetal gonad develops into a testis or ovary during the process of organogenesis. I investigate the role of blood vessels and the immune system in both gonad formation and organ homeostasis.

I first became interested in this research during my postdoctoral work in Blanche Capel’s laboratory at Duke University. We made several exciting discoveries implicating blood vessels and immune cells as major players in gonad organogenesis and reproductive health. Our lab’s work branches off those initial findings, delving deeper into how organ formation occurs and how any deviations from normal development cause various birth defects and fertility problems.

My team’s ultimate goals are to improve our understanding of how disorders or differences in sexual development arise in utero. Also, we seek to better understand how the vascular and immune systems influence gamete development and quality. So far, our findings have implications for the further study of organ formation in general, including how developmental processes are disrupted by cancer and other pathologies.

Since opening our lab in 2012, my team has learned more about the critical role of blood vessels in gonad development, including how they maintain certain stem cells. These stem cells eventually give rise to testosterone-producing Leydig cells in the fetal testis and help form the tubule structures required for proper testicular function. We have recently expanded our research to address the role of vasculature in the developing ovary, which is an under-appreciated aspect of female reproductive biology.

Additionally, we’ve learned that a specific immune system cell, the macrophage, is essential for the formation of the fetal testis. Macrophages also help regulate the differentiation of sperm stem and progenitor cells in the adult testis, as well as promoting sex steroid hormone production. We are currently studying a wide range of instructive roles for immune cells during sexually dimorphic development of the gonad.

Our initial research received a Basil O’Connor Starter Scholar Award from the March of Dimes. Since joining the Cincinnati Children’s Research Foundation community, we’ve had five published articles featured on the covers of prominent scientific journals, such as Cell Reports (three times), Biology of Reproduction, and Arteriosclerosis, Thrombosis, and Vascular Biology.

Thanks to our efforts, our lab received two major National Institutes of Health (NIH) grants from the National Institute of General Medical Sciences (NIGMS) and the National Institute of Child Health and Human Development (NICHD). We have also received foundation grants from CancerFree KIDS, Scientific Advisory Board of Vivere, and the Lalor Foundation that promotes reproductive health through research and innovation.

Since 2014, I have worked on the editorial board of Biology of Reproduction and was awarded a top Reviewing Editor Award in 2018. I also have served as a grant reviewer six times for five different National Institutes of Health study sections and for international grant agencies, including the German Research Foundation, French National Research Agency, and the European Research Council.

BA: University of Virginia, Charlottesville, VA.

PhD: Johns Hopkins University, Baltimore, MD.

Postdoc: Duke University Medical Center, Durham, NC.

Postdoc: National Institute of Genetics, Mishima, Japan.

Research Areas

Reproductive Sciences, Developmental Biology



Perivascular cells support folliculogenesis in the developing ovary. Li, S; Bhandary, B; Gu, X; DeFalco, T. Proceedings of the National Academy of Sciences of USA. 2022; 119:e2213026119.


Cdc42 activity in Sertoli cells is essential for maintenance of spermatogenesis. Heinrich, A; Bhandary, B; Potter, SJ; Ratner, N; DeFalco, T. Cell Reports. 2021; 37:109885.


Loss of Mafb and Maf distorts myeloid cell ratios and disrupts fetal mouse testis vascularization and organogenesis†. Li, S; Gu, X; Heinrich, A; Hurley, EG; Capel, B; DeFalco, T. Biology of Reproduction. 2021; 105:958-975.


A perivascular niche for multipotent progenitors in the fetal testis. Kumar, DL; DeFalco, T. Nature Communications. 2018; 9:4519.


Numb regulates somatic cell lineage commitment during early gonadogenesis in mice. Lin, Y; Barske, L; DeFalco, T; Capel, B. Development (Cambridge). 2017; 144:1607-1618.


Macrophages Contribute to the Spermatogonial Niche in the Adult Testis. DeFalco, T; Potter, SJ; Williams, AV; Waller, B; Kan, MJ; Capel, B. Cell Reports. 2015; 12:1107-1119.


Yolk-sac-derived macrophages regulate fetal testis vascularization and morphogenesis. DeFalco, T; Bhattacharya, I; Williams, AV; Sams, DM; Capel, B. Proceedings of the National Academy of Sciences of USA. 2014; 111:E2384-E2393.


Testosterone levels influence mouse fetal Leydig cell progenitors through notch signaling. DeFalco, T; Saraswathula, A; Briot, A; Iruela-Arispe, ML; Capel, B. Biology of Reproduction. 2013; 88:91.


Two distinct origins for Leydig cell progenitors in the fetal testis. DeFalco, T; Takahashi, S; Capel, B. Developmental Biology. 2011; 352:14-26.


Vascular-mesenchymal cross-talk through Vegf and Pdgf drives organ patterning. Cool, J; DeFalco, TJ; Capel, B. Proceedings of the National Academy of Sciences of USA. 2011; 108:167-172.

From the Blog

Study Reveals a Gene Crucial to Sperm Cell Production

Study Reveals a Gene Crucial to Sperm Cell Production

Tony J. De Falco, PhD10/26/2021