Jean Finnegan

Last updated

Elizabeth Jean Finnegan FAA is an Australian botanist who researches plant flowering processes and epigenetic regulation in plants. [1] [2] [3] She currently works at the Commonwealth Scientific and Industrial Research Organisation (CSIRO) as a senior scientist, leading research on the "Control of Floral Initiation", part of the CSIRO Agriculture Flagship (formerly known as CSIRO Plant Industry). [4]

Contents

Education

Finnegan received her Bachelor of Science (honours) from the University of Adelaide, and her PhD from the University of Adelaide in 1979. Her thesis was Transcriptional studies of bacteriophage 186. [5]

Recognition

Finnegan was elected a Fellow of the Australian Academy of Science in May 2014 on the basis of her world leading research on plant gene expression. [6] Her contribution to plant science includes her early work, cloning the first plant (METI), and her work demonstrating that DNA methylation (a biochemical process that modifies the plant's DNA) is essential for normal plant development [7] and by reducing levels of methylation changes the plant's size and shape, flowering time, structure of the flowers and number of seeds. [8]

In 2012, Finnegan was awarded the Julian Wells Medal for contributions to research on the organisation and expression of the genome. [9]

Finnegan is on the editorial board for BMC Plant Biology. [10]

Research

Finnegan's research focuses on epigenetic mechanisms of flowering processes in plants, specifically, the role of DNA methylation in normal plant development. DNA methylation is a biochemical process that modifies DNA, with Finnegan's work some of the first to show this in plants. She generated plants with reduced levels of DNA methylation using an antisense against METI, and determined the molecular basis for the abnormal phenotypes displayed by plants with reduced levels of methylation. [11] She continues to be a leader in her field through her research on flowering processes and the role of DNA methylation and epigenetics helping to understand the mechanisms contributing to the down-regulation of flowering locus C (FLC) in vernalized plants. [12] [13] The focus of her current research is investigating the role of DNA methylation in regulating traits of agronomic importance in wheat.

Related Research Articles

<i>Arabidopsis thaliana</i> Model plant species in the family Brassicaceae

Arabidopsis thaliana, the thale cress, mouse-ear cress or arabidopsis, is a small plant from the mustard family (Brassicaceae), native to Eurasia and Africa. Commonly found along the shoulders of roads and in disturbed land, it is generally considered a weed.

<span class="mw-page-title-main">Vernalization</span> Induction of a plants flowering process

Vernalization is the induction of a plant's flowering process by exposure to the prolonged cold of winter, or by an artificial equivalent. After vernalization, plants have acquired the ability to flower, but they may require additional seasonal cues or weeks of growth before they will actually do so. The term is sometimes used to refer to the need of herbal (non-woody) plants for a period of cold dormancy in order to produce new shoots and leaves, but this usage is discouraged.

<span class="mw-page-title-main">Antisense RNA</span> Single stranded RNA

Antisense RNA (asRNA), also referred to as antisense transcript, natural antisense transcript (NAT) or antisense oligonucleotide, is a single stranded RNA that is complementary to a protein coding messenger RNA (mRNA) with which it hybridizes, and thereby blocks its translation into protein. The asRNAs have been found in both prokaryotes and eukaryotes, and can be classified into short and long non-coding RNAs (ncRNAs). The primary function of asRNA is regulating gene expression. asRNAs may also be produced synthetically and have found wide spread use as research tools for gene knockdown. They may also have therapeutic applications.

<span class="mw-page-title-main">Repressor</span> Sort of RNA-binding protein in molecular genetics

In molecular genetics, a repressor is a DNA- or RNA-binding protein that inhibits the expression of one or more genes by binding to the operator or associated silencers. A DNA-binding repressor blocks the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes into messenger RNA. An RNA-binding repressor binds to the mRNA and prevents translation of the mRNA into protein. This blocking or reducing of expression is called repression.

The MADS box is a conserved sequence motif. The genes which contain this motif are called the MADS-box gene family. The MADS box encodes the DNA-binding MADS domain. The MADS domain binds to DNA sequences of high similarity to the motif CC[A/T]6GG termed the CArG-box. MADS-domain proteins are generally transcription factors. The length of the MADS-box reported by various researchers varies somewhat, but typical lengths are in the range of 168 to 180 base pairs, i.e. the encoded MADS domain has a length of 56 to 60 amino acids. There is evidence that the MADS domain evolved from a sequence stretch of a type II topoisomerase in a common ancestor of all extant eukaryotes.

Superman is a plant gene in Arabidopsis thaliana, that plays a role in controlling the boundary between stamen and carpel development in a flower. It is named for the comic book character Superman, and the related genes kryptonite (gene) and clark kent were named accordingly. It encodes a transcription factor. Homologous genes are known in the petunia and snapdragon, which are also involved in flower development, although in both cases there are important differences from the functioning in Arabidopsis. Superman is expressed early on in flower development, in the stamen whorl adjacent to the carpel whorl. It interacts with the other genes of the ABC model of flower development in a variety of ways.

Evolutionary developmental biology (evo-devo) is the study of developmental programs and patterns from an evolutionary perspective. It seeks to understand the various influences shaping the form and nature of life on the planet. Evo-devo arose as a separate branch of science rather recently. An early sign of this occurred in 1999.

<span class="mw-page-title-main">Caroline Dean</span> British botanist

Dame Caroline Dean is a British plant scientist working at the John Innes Centre. She is focused on understanding the molecular controls used by plants to seasonally judge when to flower. She is specifically interested in vernalisation — the acceleration of flowering in plants by exposure to periods of prolonged cold. She has also been on the Life Sciences jury for the Infosys Prize from 2018.

<span class="mw-page-title-main">PRC2</span>

PRC2 is one of the two classes of polycomb-group proteins or (PcG). The other component of this group of proteins is PRC1.

Flowering Locus C (FLC) is a MADS-box gene that in late-flowering ecotypes of the plant Arabidopsis thaliana is responsible for vernalization. In a new seedling FLC is expressed, which prevents flowering. Upon exposure to cold, less FLC is expressed, and flowering becomes possible. FLC is extensively regulated through epigenetic modifications and transcriptional control.

RNA polymerase IV is an enzyme that synthesizes small interfering RNA (siRNA) in plants, which silence gene expression. RNAP IV belongs to a family of enzymes that catalyze the process of transcription known as RNA Polymerases, which synthesize RNA from DNA templates. Discovered via phylogenetic studies of land plants, genes of RNAP IV are thought to have resulted from multistep evolution processes that occurred in RNA Polymerase II phylogenies. Such an evolutionary pathway is supported by the fact that RNAP IV is composed of 12 protein subunits that are either similar or identical to RNA polymerase II, and is specific to plant genomes. Via its synthesis of siRNA, RNAP IV is involved in regulation of heterochromatin formation in a process known as RNA directed DNA Methylation (RdDM).

<span class="mw-page-title-main">Transgenerational epigenetic inheritance</span> Epigenetic transmission without DNA primary structure alteration

Transgenerational epigenetic inheritance is the transmission of epigenetic markers and modifications from one generation to multiple subsequent generations without altering the primary structure of DNA. Thus, the regulation of genes via epigenetic mechanisms can be heritable; the amount of transcripts and proteins produced can be altered by inherited epigenetic changes. In order for epigenetic marks to be heritable, however, they must occur in the gametes in animals, but since plants lack a definitive germline and can propagate, epigenetic marks in any tissue can be heritable.

Epigenetics is the study of changes in gene expression that occur via mechanisms such as DNA methylation, histone acetylation, and microRNA modification. When these epigenetic changes are heritable, they can influence evolution. Current research indicates that epigenetics has influenced evolution in a number of organisms, including plants and animals.

Elizabeth Salisbury Dennis is an Australian scientist working mainly in the area of plant molecular biology. She is currently a chief scientist at the plant division of CSIRO Canberra. She was elected a Fellow of the Australian Academy of Technological Sciences and Engineering (FTSE) in 1987, and the Australian Academy of Science in 1995. She jointly received the inaugural Prime Minister's Science Prize together with Professor Jim Peacock in 2000 for her outstanding achievements in science and technology.

The epigenetics of plant growth and development refers to the heritable changes in gene expression that occur without alterations to the DNA sequence, influencing processes in plants such as seed germination, flowering, and stress responses through mechanisms like DNA methylation, histone modification, and chromatin remodeling.

Arabidopsis thaliana is a first class model organism and the single most important species for fundamental research in plant molecular genetics.

<span class="mw-page-title-main">Julie Law</span> American molecular and cellular biologist

Julie Law is an American molecular and cellular biologist. Law's pioneering work on DNA methylation patterns led to the discovery of the role of the CLASSY protein family in DNA methylation. Law is currently an associate professor at the Salk Institute for Biological Studies.

Robert J. Schmitz is an American plant biologist and epigenomicist at the University of Georgia where he studies the generation and phenotypic consequences of plant epialleles as well as developing new techniques to identify and study cis-regulatory sequences. He is an associate professor in the department of genetics and the UGA Foundation Endowed Pant Sciences Professor.

<span class="mw-page-title-main">RNA-directed DNA methylation</span> RNA-based gene silencing process

RNA-directed DNA methylation (RdDM) is a biological process in which non-coding RNA molecules direct the addition of DNA methylation to specific DNA sequences. The RdDM pathway is unique to plants, although other mechanisms of RNA-directed chromatin modification have also been described in fungi and animals. To date, the RdDM pathway is best characterized within angiosperms, and particularly within the model plant Arabidopsis thaliana. However, conserved RdDM pathway components and associated small RNAs (sRNAs) have also been found in other groups of plants, such as gymnosperms and ferns. The RdDM pathway closely resembles other sRNA pathways, particularly the highly conserved RNAi pathway found in fungi, plants, and animals. Both the RdDM and RNAi pathways produce sRNAs and involve conserved Argonaute, Dicer and RNA-dependent RNA polymerase proteins.

Transgenerational epigenetic inheritance in plants involves mechanisms for the passing of epigenetic marks from parent to offspring that differ from those reported in animals. There are several kinds of epigenetic markers, but they all provide a mechanism to facilitate greater phenotypic plasticity by influencing the expression of genes without altering the DNA code. These modifications represent responses to environmental input and are reversible changes to gene expression patterns that can be passed down through generations. In plants, transgenerational epigenetic inheritance could potentially represent an evolutionary adaptation for sessile organisms to quickly adapt to their changing environment.

References

  1. ↑ "Dr Jean Finnegan: understanding flowering". CSIRO. 14 October 2013. Archived from the original on 15 December 2014. Retrieved 11 November 2015.
  2. ↑ Finnegan, E. J.; Genger, R. K.; Peacock, W. J.; Dennis, E. S. (1998). "DNA Methylation in Plants". Annual Review of Plant Physiology and Plant Molecular Biology. 49: 223–247. doi:10.1146/annurev.arplant.49.1.223. PMID   15012234.
  3. ↑ Finnegan, E J; Peacock, W J; Dennis, E S (2000). "DNA methylation, a key regulator of plant development and other processes". Current Opinion in Genetics & Development. 10 (2): 217–223. doi:10.1016/S0959-437X(00)00061-7. PMID   10753779.
  4. ↑ "Dr Jean Finnegan: Understanding flowering | CSIRO". Archived from the original on 15 December 2014. Retrieved 11 November 2015.
  5. ↑ Finnegan, Elizabeth Jean (1979). Transcriptional studies of bacteriophage 186 (Thesis). Adelaide. hdl:2440/20053.
  6. ↑ "Dr Elizabeth Jean Finnegan". Australian Academy of Science. 2014. Archived from the original on 21 December 2016. Retrieved 8 December 2016.
  7. ↑ Finnegan, E J; Peacock, W J; Dennis, E S (1996). "Reduced DNA methylation in Arabidopsis thaliana results in abnormal plant development". PNAS. 93 (16): 8449–8454. Bibcode:1996PNAS...93.8449F. doi: 10.1073/pnas.93.16.8449 . PMC   38691 . PMID   8710891.
  8. ↑ Finnegan, E J; Peacock, W J; Dennis, E S (1996). "Reduced DNA methylation in Arabidopsis thaliana results in abnormal plant development". PNAS. 93 (16): 8449–8454. Bibcode:1996PNAS...93.8449F. doi: 10.1073/pnas.93.16.8449 . PMC   38691 . PMID   8710891.
  9. ↑ "Julian Wells Medal". Victoria, Australia: Lorne Genome Conference. Archived from the original on 25 September 2015. Retrieved 11 November 2015.
  10. ↑ "BMC Plant Biology Editorial Board". Archived from the original on 24 November 2011.
  11. ↑ Finnegan, E. J.; Peacock, W. J.; Dennis, E. S. (October 2014). "Reduced DNA methylation in Arabidopsis thaliana results in abnormal plant development". Proceedings of the National Academy of Sciences of the United States of America. 93 (16): 8449–8454. doi: 10.1073/pnas.93.16.8449 . PMC   38691 . PMID   8710891.
  12. ↑ Finnegan, E J; Dennis, E S (2007). "Vernalization-Induced Trimethylation of Histone H3 Lysine 27 at FLC Is Not Maintained in Mitotically Quiescent Cells". Current Biology. 17 (22): 1978–1983. doi: 10.1016/j.cub.2007.10.026 . PMID   17980595. S2CID   18167488.
  13. ↑ Jean Finnegan, E.; Kovac, Kathryn A.; Jaligot, Estelle; Sheldon, Candice C.; James Peacock, W.; Dennis, Elizabeth S. (2005). "The downregulation of FLOWERING LOCUS C (FLC) expression in plants with low levels of DNA methylation and by vernalization occurs by distinct mechanisms". The Plant Journal. 44 (3): 420–432. doi:10.1111/j.1365-313X.2005.02541.x. PMID   16236152.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.