Ubiquitous expression of CUG or CAG trinucleotide repeat RNA causes common morphological defects in a Drosophila model of RNA-mediated pathology.
Expanded DNA repeat sequences are known to cause over 20 diseases, including Huntington's disease, several types of spinocerebellar ataxia and myotonic dystrophy type 1 and 2. A shared genetic basis, and overlapping clinical features for some of these diseases, indicate that common pathways may contribute to pathology. Multiple mechanisms, mediated by both expanded homopolymeric proteins and expanded repeat RNA, have been identified by the use of model systems, that may account for shared pathology. The use of such animal models enables identification of distinct pathways and their 'molecular hallmarks' that can be used to determine the contribution of each pathway in human pathology. Here we characterise a tergite disruption phenotype in adult flies, caused by ubiquitous expression of either untranslated CUG or CAG expanded repeat RNA. Using the tergite phenotype as a quantitative trait we define a new genetic system in which to examine 'hairpin' repeat RNA-mediated cellular perturbation. Further experiments use this system to examine whether pathways involving Muscleblind sequestration or Dicer processing, which have been shown to mediate repeat RNA-mediated pathology in other model systems, contribute to cellular perturbation in this model.
Discipline of Genetics, School of Molecular and Biomedical Science and Australian Research Council Special Research Centre for the Molecular Genetics of Development, The University of Adelaide, Adelaide, South Australia, Australia.
Kynan T
KT
Lawlor
Louise V
LV
O'Keefe
Saumya E
SE
Samaraweera
Clare L
CL
van Eyk
Robert I
RI
Richards
D000818:Animals; D004195:Disease Models, Animal; D004331:Drosophila melanogaster; D005786:Gene Expression Regulation; D006801:Humans; D006816:Huntington Disease / Q000235:genetics / Q000378:metabolism*; D012313:RNA / Q000096:biosynthesis* / Q000235:genetics; D019680:Trinucleotide Repeat Expansion; D018911:Trinucleotide Repeats
D012313:RNA