Col1a1^m1Btlr

The mutation is a T-to-A transversion in the donor splice site of intron 36 (GT->GA). It is predicted to cause skipping of the 108-amino acid exon 36 (of 51 total exons), near the middle of the triple-helical domain of the collagen protein. Quantitative RT-PCR confirmed that transcripts are reduced in total RNA, nuclear RNA and cytoplasmic RNA from femurs, however the ratio of exon 36-37/exon 40-41 mRNA in the nucleus, but not the cytoplasmic or total RNA, is reduced due to reduced levels of exon 36-37 transcript compared to exon 40-41 transcript in the nuclear fraction of femurs. Sequencing of transcripts across the junction between exon 35 and the next exon show normal splicing of exon 35 to exon 36 in RNAs isolated from femurs and normal splining between exon 36 and exon 37 is also seen. (J:132554, J:253622)