Global gene expresssion profiling the gills of amoebic gill disease (AGD) affected Atlantic salmon (Salmo salar)

Amoebic gill disease (AGD) is an ectoparasitic condition of some farm-reared marine fish and is caused by Neoparamoeba perurans. Tanks housing Atlantic salmon (Salmo salar) were inoculated with Neoparamoeba perurans and fish were sampled at 36 days postinoculation (pi.). AGD-affected gill tissue was dissected from N. perurans infected fish, and a DNA microarray was used to compare global gene expression against tissues from AGD-naive fish. To determine whether the changes in gene expression were restricted to AGD-lesions, lesion tissue from AGD-affected fish was also compared with non-lesion gill tissue dissected from the same gill arch. Samples were assessed using a DNA microarray. Keywords: comparative gene expression, parasite-induced lesion, Neoparamoeba perurans, amoebic gill disease mRNA from lesion and non-lesion gill tissue was amplified and labeled. Six biological and two technical replicates were utilised to hybridise to 12 arrays using amplified RNA from AGD-affected lesion gill tissue with AGD-naive fish as a control. Four biological and two technical replicates were utilised to hybridise to 8 arrays using amplified RNA from AGD-affected lesion gill tissue with non-lesion tissue from the same gill arch as a control. The assignment of microarrays to treatment groups for hybridization was randomised by using a random number generator.