Randy Jirtle (born November 9, 1947) is an American biologist noted for his research in epigenetics, the branch of biology that deals with inherited information that does not reside in the nucleotide sequence of DNA.[Allis, CD, Jenuwein T, Reinberg D, Caparros, M-L (eds.) (2007), Epigenetics, Cold Spring Harbor, New York: Cold Spring Harbor Laboratory Press, ] Jirtle retired from Duke University, Durham, NC in 2012. He is presently Professor of Epigenetics in the Department of Biological Sciences at North Carolina State University, Raleigh, NC. ["Alumnus Randy Jirtle receives 2019 Alexander Hollaender Award"
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College of Engineering - University of Wisconsin-Madison 1 March 2019 Jirtle is noted for his research on genomic imprinting, and for his use of the Agouti mouse model to investigate the effect of environmental agents on the mammalian epigenome and disease susceptibility.
Early life and career
Jirtle was born in Kewaunee, Wisconsin. He attended Algoma Public High School and the University of Wisconsin–Madison, graduating with a B.S. degree in nuclear engineering. For graduate school, he remained at the University of Wisconsin-Madison, obtaining an M.S. in
Radiobiology in 1973 and a PhD in 1976 (Major:
Radiobiology; Minor:
Statistics). Following post-doctoral studies, Jirtle was appointed assistant professor of radiology at Duke University in 1980, and became Professor of Radiation Oncology in 1990 and Associate Professor of Pathology in 1998. He remained at Duke until 2012, and is currently Professor of Epigenetics in the Department of Biological Sciences at North Carolina State University, Raleigh, NC.
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Research
Jirtle's early research examined the influence of radiation on biological systems. He developed the first in vivo clonogenic assay for hepatocytes,[Jirtle RL, Biles C, Michalopoulos G (1980), "Morphologic and histochemical analysis of hepatocytes transplanted into syngeneic hosts", Am J Pathol 101: 115–126. ] and used it to quantify their survival when exposed to X-rays[Jirtle RL, Michalopoulos G, McLain JR, Crowley J (1981), "Transplantation system for determining the clonogenic survival of parenchymal hepatocytes exposed to ionizing radiation", Cancer Res 41: 3512–3518. ][Jirtle RL, McLain JR, Strom SC, Michalopoulos G (1982), "Repair of radiation damage in noncycling parenchymal hepatocytes", Br J Radiol 55: 847–851. ] and neutrons.[Jirtle RL, Michalopoulos G, Strom SC, DeLuca PM, Gould MN (1984), "The survival of parenchymal hepatocytes irradiated with low and high LET radiation", Br J Cancer Suppl 6: 197–201. ] Jirtle also used this clonal assay to study the phenomenon of liver regeneration.[Jirtle RL, Michalopoulos G (1982), "Effects of partial hepatectomy on transplanted hepatocytes", Cancer Res. 42: 3000–3004. ] These early studies ultimately led to the identification of the insulin-like growth factor receptor (IGF2R) as a human tumor suppressor gene,[De Souza AT, Hankins GR, Washington MK, Orton TC, Jirtle RL (1995), "M6P/IGF2R gene is mutated in human hepatocellular carcinomas with loss of heterozygosity", Nat Genet 11: 447–449. ][Hankins GR, De Souza AT, Bentley RC, Patel MR, Marks JR, Iglehart JD, Jirtle RL (1996), "M6P/IGF2 receptor: a candidate breast tumor suppressor gene", Oncogene 12: 2003–2009. ] and to studies in the emerging field of genomic imprinting, since murine IGF2R was shown at that time to be imprinted.[Barlow DP, Stoger R, Herrmann BG, Saito K, Schweifer N (1991), "The mouse insulin-like growth factor type-2 receptor is imprinted and closely linked to the locus", Nature 349: 84–87. ]
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In 2003, Jirtle provided molecular evidence that maternal dietary supplementation of Agouti viable yellow (Avy) mice with methyl donors (i.e. folic acid, choline, vitamin B12, and betaine) altered the coat color distribution and disease susceptibility in genetically identical offspring by increasing DNA methylation at the Avy locus.[Waterland RA, Jirtle RL (2003), "Transposable elements: targets for early nutritional effects on epigenetic gene regulation", Mol Cell Biol 23: 5293–5300. ][Dolinoy DC, Weidman JR, Waterland RA, Jirtle RL (2006), "Maternal genistein alters coat color and protects Avy mouse offspring from obesity by modifying the fetal epigenome", Environ Health Perspect 114: 567–572. ] showed that the phyto-estrogen, genistein, modifies the fetal epigenome, alters coat color, and protects Agouti offspring from obesity even though it is not capable of donating a methyl group.[Tilson HA (2011), "EHP Classic Paper of the Year, 2011", Environ Health Perspect 119: A238. ] It was followed by a study that showed that genistein and methyl donor supplementation can counteract detrimental epigenetic effects induced by a controversial xenobiotic chemical, bisphenol A (Bisphenol A).[Dolinoy DC, Huang D, Jirtle RL (2007), "Maternal nutrient supplementation counteracts bisphenol A-induced DNA hypomethylation in early development", PNAS 104: 13056–13061. ] Jirtle used the Avy mouse system to show that embryonic stem cells exposed in vivo to low doses of a physical agent, , induce positive adaptive responses in the offspring by altering the epigenome, and that these changes are mitigated by .[Bernal AJ, Dolinoy DC, Huang D, Skaar DA, Weinhouse C, Jirtle RL (2013), "Adaptive radiation-induced epigenetic alterations mitigated by antioxidants", FASEB J 27: 665–671. ]
He has edited a book on Liver Regeneration and Carcinogenesis,
Awards
Jirtle has received a number of awards in recognition of his achievements. He was honored in 2006 with the Distinguished Achievement Award from the College of Engineering at the University of Wisconsin-Madison.[Archived at Ghostarchive and the
target="_blank" rel="nofollow"> Wayback Machine: ] Personalized Lifestyle Medicine Institute presented Jirtle with the Research and Innovation Leadership Award in 2019.
External links
