A photo of Tony De Falco.

Associate Professor, UC Department of Pediatrics


"I investigate the role of blood vessels and the immune system in both gonad formation and organ homeostasis."

Biography & Affiliation


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.

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.

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 four published articles featured on the covers of prominent scientific journals, such as Cell Reports (twice), 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’ve 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. I also have served as a grant reviewer for five National Institutes of Health study sections and for the German Research Foundation.

Academic Affiliation

Associate Professor, UC Department of Pediatrics

Research Divisions

Reproductive Sciences, Developmental Biology


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.


Selected Publication

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

Extragonadal oocytes residing in the mouse ovarian hilum contribute to fertility. Sun, X; Ito, J; Potter, SJ; Dey, SK; DeFalco, T. Biology of Reproduction. 2017; 96:1060-1070.

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.

Role of the testis interstitial compartment in spermatogonial stem cell function. Potter, SJ; DeFalco, T. Reviews of Reproduction. 2017; 153:R151-R162.

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 the United States of America. 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.

Temporal transcriptional profiling of somatic and germ cells reveals biased lineage priming of sexual fate in the fetal mouse gonad. Jameson, SA; Natarajan, A; Cool, J; DeFalco, T; Maatouk, DM; Mork, L; Munger, SC; Capel, B. PLoS Genetics. 2012; 8.

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 the United States of America. 2011; 108:167-172.