Transcript Document
Applications of molecular techniques used in research Batten Disease Neuronal ceroid lipofuscinosis (NCL) Neurodegenerative lysosomal storage disorder At least 13 distinct human NCL genes known, all causing the same clinical features of visual failure, seizures and progressive motor and cognitive decline Naturally occurring animal models, including sheep, whose disease closely matches the human No effective therapies Batten Animal Research Network Gene therapy virus Gene therapy Disabled virus In vitro (in the lab) In vivo (in the animal) + Corrective NCL gene Corrective NCL gene packaged into virus Vector inserts gene Using DNA that encodes a functional, therapeutic NCL gene to replace the mutated or missing NCL gene Injection of the viral vector containing the corrective NCL gene into the brain of affected sheep Corrective protein produced Nucleus Target brain cell Gene expression of the missing gene and production of the corrective protein Battens Disease Research by Professor David Palmer Transposons (Evolutions “dead-mans” switch) • Mobile genetic elements = Transposons • Present in all organisms (yes - even Humans!!) – – – – The larger the genome the higher % of TEs present Humans = 50% TEs Grapes = 45% TEs Wheat = >75% TEs Transposons – things they do….. • New insertions at new locations – Can destroy gene function – Can change gene activity – Can shuffle exons making new genes with new functions • Existing and new insertions can influence the function of DNA flanking genome insertion sites = one important aspect of epigenetics Transposons – Parasites or an evolutionary force for good? • Both! - They are parasites that have been harnessed by evolution • Most TEs contain regulatory elements that respond to and are activated when the host plant is exposed to stress • It appears that retention of TEs is an evolutionary adaptation to rapid environmental change – Activation under stress conditions (release of the dead-mans switch) can introduce massive amounts of new genetic diversity within a single generation Cyclodia methylation Cyclodia Transposon Transposons & Functional genomics Develop somatic embryo cultures Recover plants Regenerate plants Activate TEs using stress Genotype to identify new element insertions and their location Screen data for mutation in key genes • Identify genes + mutation • Identify individuals in the population • Assess the phenotypic impact of the mutation • Determine the function of the gene Screen population for new phenotypes • Identify new plants with desirable traits • Interrogate database to find out what new mutations are present • Identify genes mutated • Use information to ascertain gene function and /or use as markers for rapid breeding Transposons – Research by Dr Chris Winefield Powelliphanta augusta New species of endemic giant landsnail Single population located within mine footprint Snail collected for translocation and captive management No idea of their feeding requirements Walker et al.—New Powelliphanta species from Mt Augustus Snails are nocturnal and difficult to observe feeding 173 Molecular diet analysis Using snail faeces DNA barcoding on snail feces (non invasive method) Detection of at least 18 species of earthworms eaten by the snails Information useful for the selection of new translocation sites and to feed the snails in captivity Discovery of new species of earthworms never found before Snail speciation – Research by Dr Stephane Boyer