Gemini of coiled bodies
Nuclear bodies frequently found near or associated with Cajal bodies (also called coiled bodies or CBs). Gemini of coiled bodies, or 'gems', are similar in size and shape to CBs, and often indistinguishable under the microscope. Unlike CBs, gems do not contain small nuclear ribonucleoproteins (snRNPs); they contain a protein called survivor of motor neurons (SMN) whose function relates to snRNP biogenesis. Gems are believed to assist CBs in snRNP biogenesis, and to play a role in the etiology of spinal muscular atrophy (SMA).
SMN complex
A protein complex that contains the survival motor neuron (SMN) protein and at least eight additional integral components, including the Gemin2-8 and Unrip proteins; the complex is found in the cytoplasm and in nuclear Gems, and is involved in spliceosomal snRNP assembly in the cytoplasm and in pre-mRNA splicing in the nucleus.