Research Interests of the Genetics Laboratory

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Genetics and molecular biology are used in order to decipher the way in which genes, biochemicals and environment work together to shape an organism. The Saleeba Lab philosophy is that scientific progress at the molecular level comes into its own when small molecular changes affect the phenotype of the whole organism. For this reason, our experiments combine a molecular investigation with work on the whole organism in two ways. We investigate the effect that small genetic changes have on the whole organism and we investigate the way in which phenotypic differences are encoded by the genome.

The particular system used in the lab is the investigation of the genetic component to post-embryonic development in root architecture (the ratio of branching versus linear growth) in the plant Arabidopsis thaliana. Root architecture is influenced by both genes and environment. We aim to understand the contribution of both. Using knockout mutants, we have identified a series of genes that affect the way that roots develop.

Key phrases: Molecular genetics, whole organism, genetic model organism, genotype and phenotype

Scientific passion: These projects will suit you if your scientific passion is to understand the relationship of genotype and phenotype using the tools of molecular and transmission genetics in an organism that is amenable to modern genetic methodologies.

Tools: Molecular biology, PCR, DNA extraction, crosses, tissue culture

Project 1 – The role of actin in root branching in Arabidopsis thaliana

Supervisor: Jenny Saleeba

Analysis of mutants in the lab has shown that root branching patterns are altered when the expression of the gene Severe Depolymerisation of Actin (SDA1) is altered. In this project you will cross SDA1 mutants with lines containing mutations in other actin related genes. The analysis of gene activity and plant root phenotype will be used together to understand how the expression of SDA1 fits into the coordinated expression of actin pathway genes. You will answer the question, what steps in gene expression are required to stabilise actin and allow normal root branching to take place?

Project 2 – The role of energy partitioning in root branching in Arabidopsis thaliana

Supervisor: Jenny Saleeba

Published work has shown that there is a relationship between the ready availability of the sugar-rich products of photosynthesis and a high rate of root branching in A. thaliana. In recent experiments in the lab we have discovered that the expression of the AT3G49160 gene, encoding pyruvate kinase, changes the degree to which roots branch. It is hypothesised that pyruvate kinase affects root branching via the peturbation of sugar homeostasis in the plant. In this project you will investigate the way in which the pyruvate kinase gene fits with the pathways of other known gene products in the development of roots.