Cytoplasm
In cell biology, the cytoplasm is all of the material within a cell, enclosed by the cell membrane, except for the cell nucleus. The material inside the nucleus and contained within the nuclear membrane is termed the nucleoplasm. The main components of the cytoplasm are cytosol – a gel-like substance, the organelles – the cell's internal sub-structures, and various cytoplasmic inclusions. The cytoplasm is about 80% water and usually colorless.
Circular RNA
In the cell, circRNAs are predominantly found in the cytoplasm, where the number of circular RNA transcripts derived from a gene can be up to ten times greater than the number of associated linear RNAs generated from that locus. It is unclear how circular RNAs exit the nucleus through a relatively small nuclear pore. Because the nuclear envelope breaks down during mitosis, one hypothesis is that the molecules exit the nucleus during this phase of the cell cycle. However, certain circRNAs, such as CiRS-7/CDR1as, are expressed in neuronal tissues, where mitotic division is not prevalent.