Haploinsuffciency for Znf9 in Znf9+/- mice is associated with multiorgan abnormalities resembling myotonic dystrophy.
Myotonic dystrophy type 2 is caused by a (CCTG)/(CCUG)n repeat expansion in the first intron of the ZNF9 gene. The pathomechanism for the myotonic dystrophies is not well understood and the role of ZNF9 in myotonic dystrophy type 2 pathogenesis has not been fully clarified. We characterized Znf9+/- mice, in which the expression of Znf9 was significantly decreased, and found that their phenotype reflects many of the features of myotonic dystrophy, including muscle histological morphology, and myotonic discharges and heart conduction abnormalities, shown by electromyography and electrocardiogram analysis, respectively. Znf9 is normally highly expressed in heart and skeletal muscle, where skeletal muscle chloride channel 1 (Clc1) plays an important role. Clc1 expression was dramatically decreased in Znf9+/- mice. Znf9 transgenic mice raised Znf9 and Clc1 expression and rescued the myotonic dystrophy phenotype in Znf9+/- mice. Our results suggest that the Znf9 haploinsufficiency contributes to the myotonic dystrophy phenotype in Znf9+/- mice.
Chen
Wei
W
Department of Cytokine Biology, The Forsyth Institute, Boston, MA 02115, USA.
Wang
Yucheng
Y
Abe
Yoko
Y
Cheney
Lukas
L
Udd
Bjarne
B
Li
Yi-Ping
YP
D000015:Abnormalities, Multiple / Q000235:genetics*; D000818:Animals; D000831:Animals, Newborn; D018118:Chloride Channels / Q000235:genetics / Q000378:metabolism; D004562:Electrocardiography; D004576:Electromyography; D018628:Gene Dosage; D020869:Gene Expression Profiling; D006329:Heart Conduction System / Q000002:abnormalities; D019656:Loss of Heterozygosity; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009223:Myotonic Dystrophy / Q000235:genetics*; D010641:Phenotype; D012333:RNA, Messenger / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D016335:Zinc Fingers
D018118:Chloride Channels; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C086321:CLC-1 channel; C499012:Cnbp protein, mouse