{{Short description|American developmental biologist (born 1937)}} '''David Epel''' (born 1937) is an American developmental biologist. He is the Jane and Marshall Steel Jr. Professor Emeritus of Biological Sciences at Stanford University and a researcher at Hopkins Marine Station in Pacific Grove, California.<ref name="stanfordbio">{{Cite web |title=David Epel {{!}} Department of Biology |url=https://biology.stanford.edu/people/david-epel |access-date=2026-04-08 |website=biology.stanford.edu |language=en}}</ref> His research has focused on egg activation during fertilization, the regulation of cell division, and ecological developmental biology, including embryonic responses to environmental stress. With Scott F. Gilbert, he co-authored ''Ecological Developmental Biology'', considered the first textbook in that field.<ref name="gilbert2015">{{cite book |last1=Gilbert |first1=Scott F. |last2=Epel |first2=David |title=Ecological Developmental Biology: The Environmental Regulation of Development, Health and Evolution |edition=2nd |year=2015 |publisher=Oxford University Press}}</ref><ref name="cellreview">{{cite journal |last=Montero |first=A. |year=2009 |title=Developmental Biology Meets Ecology |journal=Cell |volume=138 |pages=421–422}}</ref>
==Education== Epel received a B.A. in biological sciences from Wayne State University in 1958 and a Ph.D. in biology from the University of California, Berkeley in 1963, working in the laboratory of Daniel Mazia. He completed postdoctoral training at the University of Pennsylvania School of Medicine in the Johnson Research Foundation laboratory of Britton Chance.<ref name="stanfordbio"/><ref name="oac">{{Cite web |title=Guide to the David Epel papers SC0977 |url=https://oac.cdlib.org/findaid/ark:/13030/kt0g5034dk/entire_text/ |website=Online Archive of California |publisher=Stanford University, Department of Special Collections and University Archives |access-date=2026-05-08}}</ref>
==Career== Epel joined Stanford University's Hopkins Marine Station as an assistant professor in 1965 and remained there until 1970, when he moved to the Scripps Institution of Oceanography at the University of California, San Diego as associate professor, becoming professor in 1973.<ref name="stanfordbio"/><ref name="oac"/> During the Scripps period he spent a sabbatical year at Churchill College, Cambridge, as a Guggenheim Fellow and Overseas Fellow, in the University of Cambridge laboratory of John Gurdon. In 1977 he returned to Hopkins Marine Station, where he was the first holder of the Jane and Marshall Steel Jr. Chair in Marine Sciences and taught and conducted research until his retirement in 2009.<ref name="stanfordbio"/><ref name="hms">{{Cite web |title=Colin Pittendrigh – Director (1976–1984) |url=https://exhibits.stanford.edu/station/feature/colin-pittendrigh-director-1976-1984/ |website=Hopkins Marine Station Spotlight Exhibits |publisher=Stanford Libraries |access-date=2026-05-08}}</ref> He served as Acting Director of Hopkins Marine Station in the mid-1980s.<ref name="oac"/><ref name="hms"/>
In addition to his Stanford appointments, Epel was on the faculty of the Gamete Physiology Course at the Marine Biological Laboratory (MBL) in Woods Hole in 1972 and co-directed the MBL Embryology Course from 1975 to 1977. He taught in UNESCO gamete physiology courses held in Sardinia and Sicily, served as resident professor for the Stanford Overseas Program at the University of Oxford in 2002, and was a faculty member in a NSF international polar biology course at McMurdo Station, Antarctica, in 1996.<ref name="stanfordbio"/>
==Research== ===Cell division=== Epel's doctoral work identified problems with the experimental basis of the then-prevailing "Energy Reservoir Hypothesis," which held that energy metabolism regulated entry into cell division.<ref>{{cite journal |last=Pederson |first=T. |year=2003 |title=Historical review: An energy reservoir for mitosis, and its productive wake |journal=Trends in Biochemical Sciences |volume=28 |pages=126}}</ref>
===Fertilization=== Searching for alternative regulators of the cell cycle, Epel began postdoctoral work with Britton Chance using sea urchin eggs and ''in situ'' fluorescence measurements of pyridine nucleotides. He found that a major redox change — phosphorylation of NAD to NADP and reduction to NADPH — occurs in the first minutes after fertilization rather than at cell-cycle transitions.<ref>{{cite journal |last=Epel |first=D. |year=1964 |title=A primary metabolic change of fertilization: interconversion of pyridine nucleotides |journal=Biochemical and Biophysical Research Communications |volume=17 |pages=62–68}}</ref>
This finding redirected his research toward the events of fertilization and early development.<ref>{{cite journal |last=Epel |first=D. |year=1967 |title=Protein synthesis in sea urchin eggs: a 'late' response to fertilization |journal=Proceedings of the National Academy of Sciences |volume=57 |pages=899–906}}</ref><ref>{{cite book |last=Epel |first=D. |year=1978 |chapter=Mechanisms of activation of sperm and egg during fertilization of sea urchin gametes |editor1-last=Monroy |editor1-first=A. |editor2-last=Moscona |editor2-first=A. |title=Current Topics in Developmental Biology |volume=12 |pages=186–246 |publisher=Academic Press}}</ref> His group described the activation at fertilization of a sodium-dependent amino acid transport system that operates at the low free amino acid concentrations of seawater.<ref>{{cite journal |last=Epel |first=D. |year=1972 |title=Activation of an Na+-dependent amino acid transport system upon fertilization of sea urchin eggs |journal=Experimental Cell Research |volume=72 |pages=74–89}}</ref>
With Robert Schimke and Andrew Muchmore, Epel isolated cortical granule contents and identified the first cortical granule enzyme, a β-1,3-glucanase.<ref>{{cite journal |last1=Epel |first1=D. |last2=Weaver |first2=A.M. |last3=Muchmore |first3=A.V. |last4=Schimke |first4=R.T. |year=1969 |title=β-1,3-glucanase of sea urchin eggs: release from particles at fertilization |journal=Science |volume=163 |pages=294–296}}</ref> With Victor D. Vacquier, he later identified a trypsin-like protease released from cortical granules that contributes to the late block to polyspermy.<ref>{{cite journal |last1=Vacquier |first1=V.D. |last2=Epel |first2=D. |last3=Douglas |first3=L. |year=1972 |title=Sea urchin eggs release protease activity at fertilization |journal=Nature |volume=237 |pages=34–36}}</ref>
In collaboration with Richard Steinhardt, Epel showed that a rise in intracellular calcium activates the sea urchin egg.<ref>{{cite journal |last1=Steinhardt |first1=R.A. |last2=Epel |first2=D. |year=1974 |title=Activation of sea urchin eggs by a calcium ionophore |journal=Proceedings of the National Academy of Sciences |volume=71 |pages=1915–1919}}</ref> With Ryuzo Yanagimachi and Edward J. Carroll Jr., the work was extended across protostome and deuterostome phyla, indicating that calcium release is a general activator at fertilization.<ref>{{cite journal |last1=Steinhardt |first1=R.A. |last2=Epel |first2=D. |last3=Carroll |first3=E.J. |last4=Yanagimachi |first4=R. |year=1974 |title=Is calcium ionophore a universal activator for unfertilized eggs? |journal=Nature |volume=252 |pages=41–43}}</ref> Subsequent work with Wai Yiu Cheung and colleagues showed that calcium acts via calmodulin to activate NAD kinase, accounting for the NAD-to-NADP conversion observed earlier.<ref>{{cite journal |last1=Epel |first1=D. |last2=Patton |first2=C. |last3=Wallace |first3=R.W. |last4=Cheung |first4=W.Y. |year=1981 |title=Calmodulin activates NAD kinase of sea urchin eggs: an early event of fertilization |journal=Cell |volume=23 |pages=543–549}}</ref>
With Miles Paul and James D. Johnson, Epel showed that fertilization triggers a Na+/H+ exchange that releases acid into seawater and produces an intracellular pH increase of about 0.5 units required for egg activation.<ref>{{cite journal |last1=Johnson |first1=J.D. |last2=Epel |first2=D. |last3=Paul |first3=M. |year=1976 |title=Na+-H+ exchange is required for activation of sea urchin eggs after fertilization |journal=Nature |volume=262 |pages=661–664}}</ref> Related work examined pH and calcium changes governing the sperm acrosome reaction<ref>{{cite journal |last1=Lee |first1=H.C. |last2=Johnson |first2=C. |last3=Epel |first3=D. |year=1983 |title=Changes in internal pH associated with initiation of motility and acrosome reaction of sea urchin sperm |journal=Developmental Biology |volume=95 |pages=31–45}}</ref> and used electrically permeabilized eggs to measure changes in glucose-6-phosphate dehydrogenase activity in the pentose phosphate pathway after fertilization.<ref>{{cite journal |last1=Swezey |first1=R.R. |last2=Epel |first2=D. |year=1988 |title=Enzyme stimulation upon fertilization is revealed in electrically permeabilized sea urchin eggs |journal=Proceedings of the National Academy of Sciences |volume=85 |pages=812–816}}</ref>
In 1973, with Ralph Gwatkin, Epel co-founded the Gordon Research Conference on Fertilization, which has met biennially since.
===Ecological developmental biology=== Beginning in the 1990s, Epel turned to how embryos cope with environmental stressors. He and Scott F. Gilbert co-authored ''Ecological Developmental Biology'' (Sinauer, 2009; Oxford University Press, 2nd ed. 2015), the first textbook in the field.<ref name="gilbert2015"/><ref name="cellreview"/>
His group characterized multidrug efflux transporters expressed in eggs and embryos that expel environmental chemicals at low metabolic cost,<ref>{{cite journal |last1=Epel |first1=D. |last2=Stevenson |first2=C.A. |last3=MacManus-Spencer |first3=L.A. |last4=Luckenbach |first4=T. |last5=Smital |first5=T. |year=2008 |title=Efflux transporters: newly appreciated roles in protection against pollutants |journal=Environmental Science & Technology |volume=42 |issue=11 |pages=3914–3920}}</ref><ref>{{cite journal |last1=Cole |first1=B.J. |last2=Hamdoun |first2=A. |last3=Epel |first3=D. |year=2013 |title=Cost, effectiveness and environmental relevance of multidrug transporters in sea urchin embryos |journal=Journal of Experimental Biology |volume=216 |pages=3896–3905}}</ref> and reported that symbiotic bacteria deposited around bobtail squid eggs by maternal accessory glands protect embryos from fungal fouling during development.<ref>{{cite journal |last1=Kerwin |first1=A.H. |display-authors=etal |year=2019 |title=Shielding the Next Generation: Symbiotic Bacteria from a Reproductive Organ Protect Bobtail Squid Eggs from Fungal Fouling |journal=mBio |volume=10 |issue=5 |pages=e02376–19}}</ref>
==Awards and honors== * Guggenheim Fellow (1976–77) * Overseas Fellow, Churchill College, Cambridge (1976–77) * Fellow, American Association for the Advancement of Science (1978) * Allan V. Cox Medal for Fostering Excellence in Undergraduate Research, Stanford University (1995)<ref>{{Cite web |title=Marc Feldman received Allan V. Cox Medal |url=https://biology.stanford.edu/news/marc-feldman-received-allan-v-cox-medal |website=biology.stanford.edu |publisher=Stanford University Department of Biology |access-date=2026-05-08 |quote=Since 1988, the Cox Medal has been awarded annually to a faculty member who has established a record of excellence directing undergraduate research over a number of years.}}</ref> * Fellow, California Academy of Sciences (2000) * Ed Ricketts Memorial Award for Lifetime Achievement in Marine Science, Monterey Bay National Marine Sanctuary (2006)<ref>{{Cite news |title=Marine scientist honored for lifetime achievement |url=https://news.stanford.edu/news/2006/march1/epel-030106.html |work=Stanford Report |publisher=Stanford University |date=2006-03-01 |access-date=2026-05-08}}</ref> * M. Patricia Morse Award for Excellence and Innovation in Science Education, Society for Integrative and Comparative Biology (2020)<ref>{{Cite web |title=M. Patricia Morse Award for Excellence and Innovation in Science Education |url=https://sicb.org/awards/m-patricia-morse-award-for-excellence-and-innovation-in-science-education/ |website=sicb.org |publisher=Society for Integrative and Comparative Biology |access-date=2026-05-08}}</ref>
==Personal life== Epel was born and raised in Detroit, Michigan. He married Lois Ambush in 1960; they live in Carmel, California.
He has served on the boards of the Monterey Bay Aquarium and the Monterey Bay Aquarium Research Institute, and on the executive committee of the Sierra Club's Ventana Chapter. He was a member of the Hatton Canyon Coalition, which campaigned against a freeway routing through Hatton Canyon and contributed to its preservation as a state park.
==References== {{Reflist}}
==External links== *[https://www.stanford.edu/~depel/ Epel's Lab] *[https://oac.cdlib.org/findaid/ark:/13030/kt0g5034dk/entire_text/ David Epel papers (SC0977), Stanford University Special Collections] *[https://neurotree.org/tree.php?pid=5820 David Epel] at the Neurotree
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{{DEFAULTSORT:Epel, David}} Category:1937 births Category:Living people Category:Scientists from Detroit Category:Wayne State University alumni Category:University of California, Berkeley alumni Category:Stanford University Department of Biology faculty Category:American developmental biologists Category:Fellows of Clare Hall, Cambridge Category:Fellows of the American Academy of Arts and Sciences Category:Fellows of the American Association for the Advancement of Science Category:Fellows of the California Academy of Sciences Category:People from Pacific Grove, California