Mülhardt C, Fischer M, Gass P, Simon-Chazottes D, Guénet J L, Kuhse J, Betz H, Becker C M
Zentrum für Molekulare Biologie, Universität Heidelberg, Federal Republic of Germany.
Neuron. 1994 Oct;13(4):1003-15. doi: 10.1016/0896-6273(94)90265-8.
Mice homozygous for the spastic mutation (spa) suffer from a complex motor disorder resulting from reduced CNS levels of the adult glycine receptor isoform GlyRA, which is composed of ligand-binding alpha 1 and structural beta polypeptides. The beta subunit-encoding gene (Glyrb) was mapped near the spa locus on mouse chromosome 3. In spa/spa mice, aberrant splicing of the beta subunit pre-mRNA strikingly diminishes the CNS contents of full-length transcripts, whereas truncated beta subunit mRNAs accumulate. This is a result of exon skipping, which causes translational frameshifts and premature stop codons. Intron 5 of the spa Glyrb gene contains an L1 transposable element that apparently is causal for the aberrant splicing of beta subunit transcripts.
患有痉挛性突变（spa）的纯合子小鼠患有复杂的运动障碍，这是由于成年甘氨酸受体亚型GlyRA的中枢神经系统水平降低所致，该亚型由配体结合α1和结构β多肽组成。β亚基编码基因（Glyrb）被定位在小鼠3号染色体上的spa基因座附近。在spa/spa小鼠中，β亚基前体mRNA的异常剪接显著减少了全长转录本的中枢神经系统含量，而截短的β亚基mRNA则积累。这是外显子跳跃的结果，外显子跳跃会导致翻译移码和过早的终止密码子。spa Glyrb基因的内含子5包含一个L1转座元件，该元件显然是β亚基转录本异常剪接的原因。
