Andrew John McWalter Millar is a Scottish

chronobiologist Chronobiology is a field of biology that examines Time, timing processes, including periodic (cyclic) phenomena in living organisms, such as their adaptation to sun, solar- and moon, lunar-related rhythms. These cycles are known as biological ...

, systems biologist, and molecular geneticist. Millar is a professor at

The University of Edinburgh The University of Edinburgh (, ; abbreviated as ''Edin.'' in Post-nominal letters, post-nominals) is a Public university, public research university based in Edinburgh, Scotland. Founded by the City of Edinburgh Council, town council under th ...

and also serves as its chair of systems biology. Millar is best known for his contributions to plant circadian biology; in the Steve Kay lab, he pioneered the use of

luciferase Luciferase is a generic term for the class of oxidative enzymes that produce bioluminescence, and is usually distinguished from a photoprotein. The name was first used by Raphaël Dubois who invented the words ''luciferin'' and ''luciferase'' ...

imaging to identify circadian mutants in ''

Arabidopsis ''Arabidopsis'' (rockcress) is a genus in the family Brassicaceae. They are small flowering plants related to cabbage and mustard. This genus is of great interest since it contains thale cress (''Arabidopsis thaliana''), one of the model organ ...

''. Additionally, Millar's group has implicated the ''

ELF4 ETS-related transcription factor Elf-4 is a protein that in humans is encoded by the ''ELF4'' gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides i ...

'' gene in circadian control of flowering time in ''Arabidopsis''. Millar was elected to the

Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

in 2012 and the

Royal Society of Edinburgh The Royal Society of Edinburgh (RSE) is Scotland's national academy of science and letters. It is a registered charity that operates on a wholly independent and non-partisan basis and provides public benefit throughout Scotland. It was establis ...

in 2013.

Life

Andrew Millar was raised in

Luxembourg Luxembourg, officially the Grand Duchy of Luxembourg, is a landlocked country in Western Europe. It is bordered by Belgium to the west and north, Germany to the east, and France on the south. Its capital and most populous city, Luxembour ...

. He later attended

Cambridge University The University of Cambridge is a Public university, public collegiate university, collegiate research university in Cambridge, England. Founded in 1209, the University of Cambridge is the List of oldest universities in continuous operation, wo ...

where he received a Bachelor of Arts in 1988, studying genetics and winning University Prizes for

botany Botany, also called plant science, is the branch of natural science and biology studying plants, especially Plant anatomy, their anatomy, Plant taxonomy, taxonomy, and Plant ecology, ecology. A botanist or plant scientist is a scientist who s ...

in 1987 and genetics in 1988. After graduation, he began doctoral study in the United States at

The Rockefeller University The Rockefeller University is a private biomedical research and graduate-only university in New York City, New York. It focuses primarily on the biological and medical sciences and provides doctoral and postdoctoral education. It is classifi ...

under the mentorship of Nam-Hai Chua, FRS, and graduated in 1994 with a PhD in plant molecular genetics. He then completed a postdoctoral fellowship at the

National Science Foundation The U.S. National Science Foundation (NSF) is an Independent agencies of the United States government#Examples of independent agencies, independent agency of the Federal government of the United States, United States federal government that su ...

(NSF) Center for Biological Timing at the

University of Virginia The University of Virginia (UVA) is a Public university#United States, public research university in Charlottesville, Virginia, United States. It was founded in 1819 by Thomas Jefferson and contains his The Lawn, Academical Village, a World H ...

under the guidance of Steve A. Kay and Gene D. Block in 1995. In 1996, he joined the faculty of the

University of Warwick The University of Warwick ( ; abbreviated as ''Warw.'' in post-nominal letters) is a public research university on the outskirts of Coventry between the West Midlands and Warwickshire, England. The university was founded in 1965 as part of ...

, where he began to work on

synthetic Synthetic may refer to: Science * Synthetic biology * Synthetic chemical or compound, produced by the process of chemical synthesis * Synthetic elements, chemical elements that are not naturally found on Earth and therefore have to be created in ...

and systems biology in conjunction with plant chronobiology. He remained at Warwick until 2005, when he joined the faculty at The University of Edinburgh. Millar helped found SynthSys, a centre for synthetic and systems biology research partnered with the University of Edinburgh, in 2007.Innogen profile
.

Research

Luciferase and plant circadian biology

As a pioneering chronobiologist, Millar is known for his use of luciferase

reporters A journalist is a person who gathers information in the form of text, audio or pictures, processes it into a newsworthy form and disseminates it to the public. This is called journalism. Roles Journalists can work in broadcast, print, adverti ...

for the purpose of studying plant circadian biology. Millar began experimenting with the firefly luciferase reporter gene as a graduate student at The Rockefeller University. In 1992, Millar and colleagues fused the Arabidopsis ''cab2'' promoter and the firefly luciferase gene to establish a real-time reporter for circadian-regulated

gene expression Gene expression is the process (including its Regulation of gene expression, regulation) by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, proteins or non-coding RNA, ...

in plants. Millar tracked the rhythm of

transcription Transcription refers to the process of converting sounds (voice, music etc.) into letters or musical notes, or producing a copy of something in another medium, including: Genetics * Transcription (biology), the copying of DNA into RNA, often th ...

from the ''cab2'' promoter using a low-light video imaging system which tracks luciferase

bioluminescence Bioluminescence is the emission of light during a chemiluminescence reaction by living organisms. Bioluminescence occurs in multifarious organisms ranging from marine vertebrates and invertebrates, as well as in some Fungus, fungi, microorgani ...

. Millar hypothesized that this model could be used to isolate

mutants In biology, and especially in genetics, a mutant is an organism or a new genetic character arising or resulting from an instance of mutation, which is generally an alteration of the DNA sequence of the genome or chromosome of an organism. It i ...

in the plant circadian clock. In 1995, Millar and colleagues used this luciferase model to identify mutant ''Arabidopsis'' plants with abnormal cycling patterns. Millar's group found ''cab2'' expression to oscillate with a shorter period in '' toc1'' mutant plants compared to

wild type The wild type (WT) is the phenotype of the typical form of a species as it occurs in nature. Originally, the wild type was conceptualized as a product of the standard "normal" allele at a locus, in contrast to that produced by a non-standard, " ...

plants.W. Huang, "Mapping the core of the Arabidopsis circadian clock defines the network structure of the oscillator", ''Science'', 2012, . These methods and discoveries were published in and featured on the cover of ''

Science Science is a systematic discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe. Modern science is typically divided into twoor threemajor branches: the natural sciences, which stu ...

'' magazine in February 1995. Millar's luciferase experiments have contributed immensely to the current understanding of the

circadian clock A circadian clock, or circadian oscillator, also known as one’s internal alarm clock is a biochemical oscillator that cycles with a stable phase and is synchronized with solar time. Such a clock's ''in vivo'' period is necessarily almost exact ...

in plants. Specifically, Millar's work in 1995 and 2012 have been integral in the development of the

repressilator The repressilator is a genetic regulatory network consisting of at least one feedback loop with at least three genes, each expressing a protein that represses the next gene in the loop. In biological research, repressilators have been used to build ...

model in plants.

Role of ELF3 and ELF4

With Kay's group, Millar identified roles for the ''ELF3'' and ''

'' genes in the plant circadian system. Plants with loss-of-function mutations in ''elf3'' exhibited arrhythmicity in constant light conditions but not in constant darkness, suggesting that ''elf3'' was necessary for proper control of the clock by light. Additionally, Millar and colleagues showed that ''ELF3'' and its

paralog Sequence homology is the biological homology between DNA, RNA, or protein sequences, defined in terms of shared ancestry in the evolutionary history of life. Two segments of DNA can have shared ancestry because of three phenomena: either a sp ...

''ELF4'' are necessary for the proper rhythmic expression of two other important genes involved in the plant circadian clock, ''

Circadian Clock Associated 1 Circadian Clock Associated 1 (CCA1) is a gene that is central to the Circadian clock, circadian oscillator of angiosperms. It was first identified in ''Arabidopsis thaliana'' in 1993. CCA1 interacts with LHY and TOC1 (gene), TOC1 to form the cor ...

'' (''CCA1'') and '' Late Elongated Hypocotyl'' (LHY).C. McClung
"Plant Circadian Rhythms"
''The Plant Cell'', 2006, These early efforts greatly contributed to efforts to understand the mechanisms underlying the function of the plant circadian oscillator. ''ELF3'' and ''ELF4'' have been shown to be important mediators of light input into the plant circadian oscillator. The mechanisms underlying the oscillator's function, specifically the full extent of "ELF3" and "ELF4"'s interactions with other parts of the clock, are an active area of research.

Evolutionary biology of plant circadian clocks

In 2005, Millar and his colleagues discovered how plant circadian clocks increase photosynthesis and growth, thereby offering a selective advantage. First, they compared the

survivability Survivability is the ability to remain alive or continue to exist. The term has more specific meaning in certain contexts. Ecological Following disruptive forces such as flood, fire, disease, war, or climate change some species of flora, faun ...

of wild-type ''Arabidopsis'', which has a circadian period of about 24 hours, when grown in a 20-hour, then 24-hour, and lastly 28-hour light-dark cycle. Then they examined long (28-hour) and short (20-hour) period mutants grown in light-dark cycles that were similar to, or dissimilar from, their endogenous clock periods. In all three strains, leaves contained more

chlorophyll Chlorophyll is any of several related green pigments found in cyanobacteria and in the chloroplasts of algae and plants. Its name is derived from the Greek words (, "pale green") and (, "leaf"). Chlorophyll allows plants to absorb energy ...

when the period of the plant matched that of the environment. Additionally, both short and long period mutants fixed around 40% more carbon when exogenous periods matched their endogenous rhythms, consistent with the hypothesis of circadian resonance. Millar's experiments demonstrated one possible mechanism that has selected for circadian clock function during plant evolution.

Current research

In 2017, Millar and colleagues quantitatively explained and predicted canonical phenotypes of circadian timing in a multicellular, model organism. The research team used metabolic and physiological data to combine and extend mathematical models of rhythmic gene expression, photoperiod-dependent flowering, elongation growth, and starch metabolism within a framework model for Arabidopsis. The model predicted the effect of altered circadian timing upon particular phenotypes in clock-mutant plants. Whole-plant growth rate decreased, which was attributed to altered night-time metabolism of stored starch in addition to altered mobilisation of secondary stores of organic acids.

Positions

* BBSRC Research Development Fellow (2002–2007) * Manager of the Interdisciplinary Program for Cellular Regulation (2003–2004) * Professor of Systems Biology, University of Edinburgh (2005–present) * Founding Director of the Centre for Systems Biology at Edinburgh (2007–2011) * Elected

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member (2011) * Fellow of the

(2012) Resigned from the society on 12 February 2025 because of the Royal Society’s “inability to take proportionate action on Elon Musk’s current promotion of disinformation”. * Fellow of the

(2013)Royal Society of Edinburgh profile.
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Awards

Society for Experimental Biology The Society for Experimental Biology is a learned society for animal, cell and plant biologists. It was founded in 1923 at Birkbeck College to "promote the art and science of experimental biology in all its branches". It aims to demonstrate the im ...

President's Medal (1999) *

British Association for the Advancement of Science The British Science Association (BSA) is a Charitable organization, charity and learned society founded in 1831 to aid in the promotion and development of science. Until 2009 it was known as the British Association for the Advancement of Scienc ...

Charles Darwin Award Lecture (2000) *

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Award for Scottish Research (2009) * Aschoff's Rule (2015)

References

{{DEFAULTSORT:Millar, Andrew Year of birth missing (living people) Living people Alumni of the University of Cambridge Place of birth missing (living people) Rockefeller University alumni Scottish geneticists Fellows of the Royal Society Fellows of the Royal Society of Edinburgh Members of the European Molecular Biology Organization