Maltese scientists show how fruit flies can cure spinal atrophy

Maltese scientists have shown how the common fruit fly Drosophila, which is genetically and biologically similar to humans, could now be used to develop new therapies for the most common genetic killer of childhood - spinal muscular atrophy (SMA).

SMA causes death of the nerve cells - motor neurons - responsible for controlling body movement, slowly leading to muscle weakness and eventually causing death. The majority of the cases are due to an inherited flaw in the gene encoding for the Survival Motor Neuron (SMN) protein.

Together, SMN and a collective of diverse proteins known as Gemins, guard against abnormalities in messenger RNA, the genetic "mail carrier" of instructions for building proteins.

Researchers from the University of Malta School of Medicine have been using the fruit fly as a model organism to study the biology of the SMN-Gemins family in brain and muscle. Their latest research demonstrates that the disruption of the Gemin associates of SMN in either brain or muscle, depresses the flight performance of flies, rendering them flightless.

Like any body movement in humans, active flight in flies is dependent on muscle capable of generating sufficient forces to offset gravity, and a controlling system provided by the brain to keep flies from tumbling to the ground. The expansive motor behaviour of flies have made them superb model organisms of neurodegenerative disease worldwide.

For the first time in Malta, the team made use of DNA-technology and a glowing tag derived from jellyfish - green fluorescent protein (GFP) - to follow their movement within cells. GFP enabled researchers to track the otherwise invisible Gemin proteins to the vault containing the instruction manual for life - DNA. 

Dr Ruben Cauchi, lead author from the University's School of Medicine said: "We were crazy enough to use biotechnology tools to engineer, from scratch, normal and mutant proteins, and to generate genetically-modified organisms that can express these proteins in every single cell of their body.  What motivates us? We are essentially curious, hungry for discovery, and have one mission - that of understanding one of the most catastrophic of diseases and its eventual eradiation.

"Our next step is to investigate whether the Gemin proteins, which remain undamaged in SMA, can functionally replace SMN. The fruit fly, which for more than a century has been a workhorse of genetics in the laboratory, is the only animal in which we can rapidly, economically, and effectively test this therapeutic strategy".

The study entitled 'The Gemin Associates of Survival Motor Neuron are Required for Motor Function in Drosophila' by Rebecca Borg and Ruben Cauchi was partly funded by Malta Council for Science & Technology (MCST) through the National Research & Innovation Programme 2012 and published in PLOS ONE: http://dx.plos.org/10.1371/journal.pone.0083878

Dr Ruben Cauchi is an academic member of staff in the Department of Physiology and Biochemistry at the Faculty of Medicine & Surgery.