F. Kent Hamra was born in Kennett,Missouri in 1965. He received his B.S. in Zoology at Southern Illinois University in Carbondale in 1989, and then went on to work with Dr. Mark G. Currie studying nitric oxide synthases and soluble guanylyl cyclases at Monsanto Company in St. Louis, Missouri from 1990-1992. He earned his Ph.D. in Pharmacology in the laboratory of Dr. Leonard R. Forte at the University of Missouri-Columbia in 1995 where he discovered the polypeptide hormone, Uroguanylin. Uroguanylin is an endogenous ligand for the highly pathogenic heat-stable enterotoxin receptor-guanylyl cyclase. Kent went on to do his postdoctoral training in the Department of Pharmacology at UT Southwestern Medical Center in Dallas with Dr. David L. Garbers (HHMI), and co-mentor, Dr. Robert E. Hammer (HHMI – Biochemistry), where he invented culture conditions for isolating, propagating and genetically modifying sperm stem cells using the rat model (1996-2000). Dr. Hamra was promoted to Instructor in 2000, Research Assistant Professor in 2004, and to Assistant Professor in 2010 in the Department of Pharmacology at UT Southwestern in Dallas, where he continues his research on spermatozoan development and fertility regulation.
Dr. Hamra's research is based on the extraordinary biomedical potential of Sperm Stem Cells as it relates to advancing animal genetics, species conservation, human reproduction and well being (visit Hamra Lab). Anatomically, sperm stem cells are technically termed “spermatogonial stem cells” (1), which function in testes by continuously regenerating mature spermatozoa for fertilizing eggs (2). Research in the Hamra lab is aimed at exploiting rat phenotypic novelty to annotate traits that enhance donor stem cell potency and specify the spermatogenic lineage. Our goal is to translate information we extract from novel genetic architecture in rat spermatogonial stem cells to pharmacologically enhance the experimental tractability, potency and effectiveness of donor spermatogonial stem cells from additional species important for science and medicine. Defining molecular mechanisms that control spermatogenesis holds significant implications for human health and disease linked to organ development, tissue regeneration and fertilization.
1. The germline stem cell niche unit in mammalian testes. Oatley JM, Brinster RL., Physiol Rev. 2012 Apr;92(2):577-95.
2. Generation of pluripotent stem cells from neonatal mouse testis. Kanatsu-Shinohara M, Inoue K, Lee J, Yoshimoto M, Ogonuki N, Miki H, Baba S, Kato T, Kazuki Y, Toyokuni S, Toyoshima M, Niwa O, Oshimura M, Heike T, Nakahata T, Ishino F, Ogura A, Shinohara T., Cell. 2004 Dec 29;119(7):1001-12.
- Southern Illinois University-C (1989), Zoology
- Graduate School
- University of Missouri-Saint L (1995), Pharmacology
- Advancing Genetics in the Laboratory Rat
- Genetic Basis of Spermatogenesis
- Mechanisms of Spermatogonial Development
- Mutagenesis in the Rat using Sperm Stem Cells
- Targeting Spermatozoan Development for Fertility Management
- Gene targeting: Enter the rat.
- Hamra FK Nature 2010 Sep 467 7312 161-3
- Generating knockout rats by transposon mutagenesis in spermatogonial stem cells.
- Izsvák Z, Fröhlich J, Grabundzija I, Shirley JR, Powell HM, Chapman KM, Ivics Z, Hamra FK Nat. Methods 2010 Jun 7 6 443-5
- Identification of neuregulin as a factor required for formation of aligned spermatogonia.
- Hamra FK, Chapman KM, Nguyen D, Garbers DL J. Biol. Chem. 2007 Jan 282 1 721-30
- Self renewal, expansion, and transfection of rat spermatogonial stem cells in culture.
- Hamra FK, Chapman KM, Nguyen DM, Williams-Stephens AA, Hammer RE, Garbers DL Proc. Natl. Acad. Sci. U.S.A. 2005 Nov 102 48 17430-5
- Defining the spermatogonial stem cell.
- Hamra FK, Schultz N, Chapman KM, Grellhesl DM, Cronkhite JT, Hammer RE, Garbers DL Dev. Biol. 2004 May 269 2 393-410
- A multitude of genes expressed solely in meiotic or postmeiotic spermatogenic cells offers a myriad of contraceptive targets.
- Schultz N, Hamra FK, Garbers DL Proc. Natl. Acad. Sci. U.S.A. 2003 Oct 100 21 12201-6
- Production of transgenic rats by lentiviral transduction of male germ-line stem cells.
- Hamra FK, Gatlin J, Chapman KM, Grellhesl DM, Garcia JV, Hammer RE, Garbers DL Proc. Natl. Acad. Sci. U.S.A. 2002 Nov 99 23 14931-6
- Autoimmune epididymoorchitis is essential to the pathogenesis of male-specific spondylarthritis in HLA-B27-transgenic rats.
- Taurog JD, Rival C, van Duivenvoorde LM, Satumtira N, Dorris ML, Sun M, Shelton JM, Richardson JA, Hamra FK, Hammer RE, Tung KS Arthritis Rheum. 2012 Aug 64 8 2518-28
- Sleeping Beauty transposon mutagenesis in rat spermatogonial stem cells.
- Ivics Z, Izsvák Z, Medrano G, Chapman KM, Hamra FK Nat Protoc 2011 Oct 6 10 1521-35
- Foxo1 is required in mouse spermatogonial stem cells for their maintenance and the initiation of spermatogenesis.
- Goertz MJ, Wu Z, Gallardo TD, Hamra FK, Castrillon DH J. Clin. Invest. 2011 Sep 121 9 3456-66
- American Society for Andrology (2008)
- Society for the Study of Reproduction (2008)