Competition of β-Methylamino-L-alanine (BMAA) with Alanine and other Natural Amino Acids in Drosophila Melanogaster

The neurotoxin β-Methylamino-L-alanine (BMAA) is found in cycad seeds; it is produced by the cyanobacteria “Nostoc” and other species of cyanobacteria.  BMAA is thought to be a causative agent for the neurodegenerative disease, amyotrophic lateral sclerosis/Parkinsonism-dementia complex (ALS/PDC). BMAA is thought to cause neurotoxicity by increasing membrane permeability causing excitotoxicity, eventually leading to neuronal death. Experiments tested if BMAA can be outcompeted with Alanine, a structurally similar amino acid, along with other natural amino acids (e.g. lysine). BMAA and a concentration of a competing amino acid were fed to age and gender-matched Canton-S fruit flies.  Our method required three independent groups of ten Drosophila Melanogaster per vial with treatment. The control group was fed normal food, during the five-day feeding period. The experimental groups where fed the competing amino acid at a 12.5 mM, 25 mM, and 50 mM concentration of BMAA. The acute effects were studied by recording the viability of the various treated fly groups during the five-day feeding period. Lysine appears to rescue the acute loss of viability with BMAA alone. Sequential treatment and competition with each of the twenty natural amino acids will give insight into the structure-function relationship between BMAA and its role in neuronal dysfunction.