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Dr. W.J. Goodrich (Senior Lecturer in Developmental Biology)

 

Our Research Interests: Epigenetic control of plant development

DNA is packaged on nucleosomes, made of histone proteins. Many different modifications of the histone tails occur and are linked with changes in gene activity and DNA compaction. Some modifications can be very stable, and in some cases are heritable through mitotis or even meiosis. Such changes are termed epigenetic; they differ from genetic changes in that DNA sequence is not altered and changes can be reversed more readily.

 

We are interested in the epigenetic control of plant development. Because epigenetic changes are stable during the life of an organism, but can be reset each new generation, they can be used to provide cells with a ‘memory’ of transient developmental events. We have identified several genes which provide plant cells with an epigenetic memory of their identity. Recent research suggests they do this by regulating histone methylation, leading to stable changes in expression of specific target genes:

The CURLY LEAF gene encodes a histone methyltransferase enzyme. Mutants are early flowering and have curled leaves. These defects arise because the gene AGAMOUS, normally expressed only in flowers, is activated precociously during vegetative development

Double mutants for CURLY LEAF and SWINGER show a more extreme phenotype. Plants are only viable if grown in tissue culture and form callus with somatic embryos. Cytogenetic analysis indicates that these plants have gross defects in histone methylation patterns

Current Research Aims:

To identify novel plant Polycomb genes and their antagonists, we conducted a large genetic screen for mutations modifying polycomb mutant phenotypes. We have isolated several of the genes involved and are characterising how they regulate gene activity. In collaboration with the group of Gwyneth Ingram, we are also analysis the role of the ZHOUPI (ZOU) gene in regulating epidermal development during embryogenesis in Arabidopsis. The ZOU gene encodes a transcription factor that promotes signalling from the endosperm to the young embryo and is required for normal epidermal development. We have identified several novel targets of ZOU and are currently testing their role in seed development.

 We acknowledge the support of 

 

 

 

THE DARWIN TRUST OF EDINBURGH