Cajal bodies (coiled bodies, CBs) are nuclear organelles of unknown function and 
are characterized by a wide variety of components including various basal 
transcription and cell cycle proteins, the nucleolar proteins fibrillarin and 
Nopp140, numerous small nuclear ribonucleoproteins, the survival motor neuron 
protein complex, and the marker protein, p80 coilin. To gain insight into the 
role of p80 coilin in CBs, we have cloned the murine gene Coil and have mapped 
it to the distal portion of chromosome band 11D. The approximately 2.6-kb 
transcript is detectable in all tissues analyzed, with the highest levels in 
brain and testis. Sequence analysis shows that, like its human counterpart, the 
mouse coilin gene is composed of seven exons and spans nearly 30 kb of genomic 
DNA. The predicted amino acid sequence reveals two conserved N- and C-terminal 
domains, and comparison with the Xenopus SPH-1 protein reveals that these three 
genes are indeed orthologous. These results should facilitate gene disruption 
experiments aimed at creating a genetic model system to study CBs.