Ian Wilmut | British Biologist, Geneticist & Scientist

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class="md-content"> <div class="md-article-container template-desktop infinite-pagination"> <div class="infinite-scroll-container article last"> <article class="article-content container-lg qa-content px-0 pt-0 pb-40 py-lg-20 content md-expanded" data-topic-id="644616"> <div class="grid gx-0"> <div class="col-auto"> <div class="topic-left-rail md-article-drawer position-relative d-flex border-right-sm border-left-sm open"> <div class="drawer d-flex flex-column open"> <div class="left-rail-section-content"> <div class="topic-left-rail-header text-truncate bg-gray-50 position-relative text-right d-flex align-items-center"> <div class="tlr-title px-20 py-15 text-left"> <em class="material-icons text-gray-400 d-lg-none" data-icon="toc"></em> <a class="font-serif font-weight-bold text-black link-blue" href="https://www.britannica.com/biography/Ian-Wilmut">Ian Wilmut</a> </div> <button aria-label="Close" class="js-sections-close-button btn-link btn-sm btn d-lg-none position-absolute top-0 p-10 right-0" > <em class="material-icons font-26" data-icon="close"></em> </button> </div> <div class="section-content pl-10 pr-20 pl-sm-50 pr-sm-60 pl-lg-5 pr-lg-10 pt-10 pt-lg-0 bg-gray-50 clear-catfish-ad"> <div class="toc mb-20"> <div class="font-serif font-14 font-weight-bold mx-15 mb-15 mt-20"> Table of Contents </div> <ul class="list-unstyled my-0" data-level="h1"><li data-target="#ref1"><div class="pl-25"><a class="link-gray-900 w-100" href="/biography/Ian-Wilmut">Introduction</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li><li data-target="#ref281346"><div class="d-flex align-items-center"><div class="ml-25"></div><a class="w-100 link-gray-900" href="/biography/Ian-Wilmut#ref281346">Education and cryopreservation research</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li><li data-target="#ref281347"><div class="d-flex align-items-center"><button class="h1-link-drawer-button btn btn-xs btn-circle d-flex rounded" type="button" aria-label="Toggle Heading"><em class="material-icons font-18" data-icon="keyboard_arrow_right"></em></button><a class="w-100 link-gray-900" href="/biography/Ian-Wilmut#ref281347">Genetic engineering and cloning research</a></div><div class="ml-40 toc-drawer sub-toc-drawer"><ul class="list-unstyled" data-level="h2"><li data-target="#ref281348"><a class="w-100 link-gray-900" href="/biography/Ian-Wilmut#ref281348">Pharming</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref281349"><a class="w-100 link-gray-900" href="/biography/Ian-Wilmut#ref281349">Nuclear transfer</a></li></ul><ul class="list-unstyled" data-level="h2"><li data-target="#ref281350"><a class="w-100 link-gray-900" href="/biography/Ian-Wilmut/Dolly-and-Polly">Dolly and Polly</a></li></ul></div></li><li data-target="#ref281351"><div class="d-flex align-items-center"><div class="ml-25"></div><a class="w-100 link-gray-900" href="/biography/Ian-Wilmut/Dolly-and-Polly#ref281351">Later career</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li></ul> <a class="toc-extra-link link-gray-900" href="https://www.britannica.com/biography/Ian-Wilmut/additional-info">References & Edit History</a> <a class="toc-extra-link link-gray-900" href="/facts/Ian-Wilmut">Quick Facts & Related Topics</a> </div> <div class="tlr-media-slider pb-10 mb-30"> <a class="section-header link-gray-900 font-serif font-14 font-weight-bold mb-10 mx-10" href="https://www.britannica.com/biography/Ian-Wilmut/images-videos">Images</a> <div class="slider js-slider position-relative d-inline-flex align-items-center mw-100 "> <div class="slider-container js-slider-container overflow-hidden d-flex overflow-hidden text-nowrap ml-15"> <a href="https://cdn.britannica.com/10/70110-050-8EF59E17/Dolly-process-sheep-somatic-cell-nuclear-transfer.jpg" data-href="/media/1/644616/60421" class="media-overlay-link d-inline-block mr-5"> <img loading="lazy" 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She joined Britannica in 2006 and...</div> </a> <div data-popper-arrow></div> </div> <span class="btn btn-link editor-link p-0 qa-byline-link gtm-byline font-12 byline-contributor text-decoration-underline"> Kara Rogers</span></div> <div class="font-serif font-12 text-gray-700"> <span class="qa-fact-checked-by">Fact-checked by</span> <div class="editor-popover popover p-0"> <a class="d-block p-20 font-12" href="/editor/The-Editors-of-Encyclopaedia-Britannica/4419" > <div class="editor-title font-16 font-weight-bold">The Editors of Encyclopaedia Britannica</div> <div class="editor-description font-12 font-serif mt-5 text-black">Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree. 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href="/place/England">England</a></dd> </dl> <button class="js-more-btn d-none btn btn-unstyled font-12 bg-gray-50" aria-label="Toggle more/less fact data"> <em class="js-content link-blue">(Show more)</em> </button> </div> </div> <div class=""> <div class="js-fact mb-10 line-clamp clamp-3"> <dl> <dt>Died: </dt> <dd>September 10, 2023 (aged 79)</dd> </dl> <button class="js-more-btn d-none btn btn-unstyled font-12 bg-gray-50" aria-label="Toggle more/less fact data"> <em class="js-content link-blue">(Show more)</em> </button> </div> </div> <div class=""> <div class="js-fact mb-10 line-clamp clamp-3"> <dl> <dt>Also Known As: </dt> <dd>Sir Ian Wilmut</dd> </dl> <button class="js-more-btn d-none btn btn-unstyled font-12 bg-gray-50" aria-label="Toggle more/less fact data"> <em class="js-content link-blue">(Show more)</em> </button> </div> </div> <div class=""> <div class="js-fact mb-10 line-clamp clamp-3"> <dl> <dt>Subjects Of Study: </dt> <dd><a href="/science/clone-genetics">clone</a></dd> <dd><a href="/science/genetic-engineering">genetic engineering</a></dd> <dd><a href="/science/nuclear-transfer">nuclear transfer</a></dd> <dd><a href="/science/pharming">pharming</a></dd> <dd><a href="/technology/cryopreservation">cryopreservation</a></dd> <dd><a href="/topic/Frostie">Frostie</a></dd> </dl> <button class="js-more-btn d-none btn btn-unstyled font-12 bg-gray-50" aria-label="Toggle more/less fact data"> <em class="js-content link-blue">(Show more)</em> </button> </div> <div class="text-center"> <a class="btn btn-sm btn-link p-0" href="/facts/Ian-Wilmut"> See all related content </a> </div> </div> </div> </div><span class="marker before-article"></span><section data-level="1" id="ref1"><span class="marker PREMOD1 mod-inline"></span><p class="topic-paragraph"><strong><span id="ref1025562"></span>Ian Wilmut</strong> (born July 7, 1944, Hampton Lucy, Warwickshire, England—died September 10, 2023) was a British developmental biologist who was the first to use nuclear transfer of <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="differentiated" href="https://www.merriam-webster.com/dictionary/differentiated" data-type="MW">differentiated</a> adult <a href="https://www.britannica.com/science/cell-biology" class="md-crosslink " data-show-preview="true">cells</a> to generate a mammalian <a href="https://www.britannica.com/science/clone-genetics" class="md-crosslink " data-show-preview="true">clone</a>, a Finn Dorset <a href="https://www.britannica.com/animal/domesticated-sheep" class="md-crosslink " data-show-preview="true">sheep</a> named <a href="https://www.britannica.com/topic/Dolly-cloned-sheep" class="md-crosslink " data-show-preview="true">Dolly</a>, born in 1996.</p><span class="marker MOD1 mod-inline"></span></section> <span class="marker h2"></span><section data-level="1" id="ref281346"> <h2 class="h1">Education and <span id="ref1107620"></span><a href="https://www.britannica.com/technology/cryopreservation" class="md-crosslink " data-show-preview="true">cryopreservation</a> research</h2> <span class="marker PREMOD2 mod-inline"></span><p class="topic-paragraph">Wilmut was raised in Coventry, a town in the historic English county of <a href="https://www.britannica.com/place/Warwickshire" class="md-crosslink " data-show-preview="true">Warwickshire</a>, and he attended the Agricultural College at the University of Nottingham. In his undergraduate studies, Wilmut initially pursued his lifelong interest in <a href="https://www.britannica.com/topic/agriculture" class="md-crosslink autoxref " data-show-preview="true">farming</a>, particularly in raising animals such as sheep. However, he soon turned his attention to animal <a href="https://www.britannica.com/science/science" class="md-crosslink autoxref " data-show-preview="true">science</a> and basic research. In 1966, his final year at Nottingham, he received a scholarship to conduct research for a summer under English biologist Ernest John Christopher Polge in the Unit of Reproductive Physiology and Biochemistry, then a division of the Agricultural Research Council at the <a href="https://www.britannica.com/topic/University-of-Cambridge" class="md-crosslink " data-show-preview="true">University of Cambridge</a>. During this time, Wilmut performed basic experiments on animal <a href="https://www.britannica.com/science/embryo-human-and-animal" class="md-crosslink " data-show-preview="true">embryos</a>. Following his graduation from Nottingham in 1967, he returned to Cambridge, where he pursued a doctorate under the guidance of Polge, whose research was focused on improving methods of embryo <a href="https://www.britannica.com/technology/cryopreservation" class="md-crosslink " data-show-preview="true">cryopreservation</a>. In 1971 Wilmut was awarded a doctorate by Darwin College, Cambridge; the title of his <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="thesis" href="https://www.britannica.com/dictionary/thesis" data-type="EB">thesis</a> was “Deep Freeze Preservation of Boar Semen.” Wilmut remained at Cambridge and conducted extensive research on the cryopreservation of embryos. In 1973 he successfully implanted into a surrogate <a href="https://www.britannica.com/animal/cow" class="md-crosslink " data-show-preview="true">cow</a> a calf embryo that had been cryopreserved. The embryo was carried to term, and Wilmut named the first-ever “frozen calf” <span id="ref1107621"></span><a href="https://www.britannica.com/topic/Frostie" class="md-crosslink " data-show-preview="true">Frostie</a>.</p><span class="marker MOD2 mod-inline"></span> </section> <span class="marker h3"></span><section data-level="1" id="ref281347"> <h2 class="h1">Genetic engineering and <span id="ref1107618"></span><a href="https://www.britannica.com/science/clone-genetics" class="md-crosslink " data-show-preview="true">cloning</a> research</h2> <section data-level="2" id="ref281348"> <h2 class="h2"><span id="ref1107619"></span><a href="https://www.britannica.com/science/pharming" class="md-crosslink " data-show-preview="true">Pharming</a></h2> <span class="marker PREMOD3 mod-inline"></span><p class="topic-paragraph">In 1973 Wilmut was appointed senior scientific officer at the Animal Breeding Research Organisation (ABRO; renamed Edinburgh Research Station of the Institute of Animal Physiology and Genetics Research in 1985 and finally <span id="ref1107622"></span><a href="https://www.britannica.com/topic/Roslin-Institute" class="md-crosslink ">Roslin Institute</a> in 1993), a government-supported research facility located in Roslin, Scot., just south of <a href="https://www.britannica.com/place/Edinburgh-Scotland" class="md-crosslink " data-show-preview="true">Edinburgh</a>. At the ABRO facility, Wilmut studied embryo development and became interested in the underlying causes of embryo death in <a href="https://www.britannica.com/animal/mammal" class="md-crosslink " data-show-preview="true">mammals</a>. However, in the early 1980s, changes in ABRO leadership and a shift in the focus of government research projects forced Wilmut into the realm of <span id="ref1107623"></span><a href="https://www.britannica.com/science/genetic-engineering" class="md-crosslink " data-show-preview="true">genetic engineering</a>. The new goal of ABRO was to generate sheep genetically engineered to produce large quantities of human <a href="https://www.britannica.com/science/protein" class="md-crosslink " data-show-preview="true">proteins</a> that would be suitable for <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="therapeutic" href="https://www.britannica.com/dictionary/therapeutic" data-type="EB">therapeutic</a> uses, a pursuit that came to be known as “pharming.” Although Wilmut had little experience with genetic engineering and had limited enthusiasm for the project, he used his knowledge of developmental <a href="https://www.britannica.com/science/biology" class="md-crosslink autoxref " data-show-preview="true">biology</a> to obtain zygotes (one-celled embryos) from sheep and developed techniques to inject <a href="https://www.britannica.com/science/DNA" class="md-crosslink " data-show-preview="true">DNA</a> into the zygote pronucleus (a haploid <a href="https://www.britannica.com/science/nucleus-biology" class="md-crosslink " data-show-preview="true">nucleus</a> occurring in embryos prior to <a href="https://www.britannica.com/science/fertilization-reproduction" class="md-crosslink " data-show-preview="true">fertilization</a>). This work eventually led to the generation of a sheep named <span id="ref1107624"></span><a href="https://www.britannica.com/topic/Tracy-sheep" class="md-crosslink ">Tracy</a>. Tracy was created from a zygote genetically engineered through DNA injection to produce milk containing large quantities of the human <a href="https://www.britannica.com/science/enzyme" class="md-crosslink " data-show-preview="true">enzyme</a> alpha-1 antitrypsin, a substance used to treat <a href="https://www.britannica.com/science/cystic-fibrosis" class="md-crosslink " data-show-preview="true">cystic fibrosis</a> and <a href="https://www.britannica.com/science/emphysema" class="md-crosslink " data-show-preview="true">emphysema</a>.</p><span class="marker MOD3 mod-inline"></span> </section> <section data-level="2" id="ref281349"> <h2 class="h2"><span id="ref1107625"></span><a href="https://www.britannica.com/science/nuclear-transfer" class="md-crosslink " data-show-preview="true">Nuclear transfer</a></h2> <span class="marker PREMOD4 mod-inline"></span><p class="topic-paragraph">Wilmut’s initial <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="forays" href="https://www.britannica.com/dictionary/forays" data-type="EB">forays</a> into <a href="https://www.britannica.com/science/cloning" class="md-crosslink " data-show-preview="true">cloning</a> began in the late 1980s with <span id="ref1107626"></span><a href="https://www.britannica.com/science/stem-cell#ref236918" class="md-crosslink " data-show-preview="true">embryonic stem cells</a>. Wilmut and his colleagues were interested primarily in nuclear transfer, a technique first conceived in 1928 by German embryologist <a href="https://www.britannica.com/biography/Hans-Spemann" class="md-crosslink " data-show-preview="true">Hans Spemann</a>. Nuclear transfer involves the introduction of the nucleus from a <a href="https://www.britannica.com/science/cell-biology" class="md-crosslink " data-show-preview="true">cell</a> into an enucleated <a href="https://www.britannica.com/science/egg-biology" class="md-crosslink " data-show-preview="true">egg</a> cell (an egg cell that has had its own nucleus removed). This can be accomplished through fusion of the cell to the egg (the technique that Wilmut used in all his later <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="cloning" href="https://www.britannica.com/dictionary/cloning" data-type="EB">cloning</a> experiments) or through the removal of the nucleus from the cell and the subsequent transplantation of that nucleus into the enucleated egg cell (a technique refined in the early 2000s). In 1989 Wilmut and Lawrence Smith, a graduate student conducting his thesis research at Roslin, generated four cloned lambs by using <span id="ref1107627"></span><a href="https://www.britannica.com/science/embryonic-cell-nuclear-transfer" class="md-crosslink ">embryonic cell nuclear transfer</a>, in which the nucleus from an embryonic stem cell was inserted into an enucleated egg. This research led Wilmut and Smith to an important discovery—namely, that the stage of the <a href="https://www.britannica.com/science/cell-cycle" class="md-crosslink autoxref " data-show-preview="true">cell cycle</a> (the sequence through which each cell progresses from one <a href="https://www.britannica.com/science/cell-division" class="md-crosslink " data-show-preview="true">cell division</a> to the next) at the time of nuclear transfer determined the success or failure of the experiment. They realized that the four clones they had generated happened by chance.</p><div class="one-good-fact-module"> </div><span class="marker MOD4 mod-inline"></span> <span class="marker PREMOD5 mod-inline"></span><p class="topic-paragraph">In 1991 Wilmut hired English biologist <span id="ref1107628"></span>Keith Campbell (Smith had left the research centre in 1990), whose knowledge of the cell cycle proved instrumental in advancing the technique of nuclear transfer developed at Roslin. Wilmut and Campbell’s first major success came in 1995, with the generation of two cloned Welsh <a href="https://www.britannica.com/animal/bighorn-sheep" class="md-crosslink autoxref " data-show-preview="true">mountain sheep</a>, Megan and Morag. The following year Wilmut, Campbell, and their team of scientists decided to test a new theory based on the idea that the age or the stage of differentiation of a donor cell did not matter in nuclear transfer. Prior to this theory, nuclear transfer was believed to work only if the nucleus used as the donor for nuclear transfer came from a cell that was totipotent—i.e., having the ability to <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="differentiate" href="https://www.merriam-webster.com/dictionary/differentiate" data-type="MW">differentiate</a> into any type of cell in the body and therefore possessing no characteristics of differentiation itself. However, observations from laboratory experiments and from Megan and Morag, who were produced using nine-day-old embryonic cells, which are presumably less totipotent than younger embryonic cells, indicated that an enucleated host egg could somehow reverse the differentiation of the donor cell nucleus, converting it back to a state of totipotency or pluripotency (slightly more differentiated than a totipotent cell). This led to the idea of using the nucleus from an already differentiated adult cell as a donor nucleus.</p><a class="link-module shadow-sm d-block qa-quiz-module" href="/quiz/genetics-quiz" data-link-module-iframe-link=""> <img loading="lazy" src="https://cdn.britannica.com/73/151873-131-8F1BD5BC/illustration-strands-DNA.jpg" alt="Illustrated strands of DNA. 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Ian Wilmut | British Biologist, Geneticist & Scientist | Britannica