"A completely new category of circular RNAs has been discovered, adding another layer of amazing complexity to human genetics. These circular RNAs are formed from the intron regions inside a gene that were once thought to be nothing but junk DNA.
Genes in plants and animals are copied (transcribed) into messenger RNA molecules (mRNAs) that
are subsequently processed to remove segments that do not end up in the mature RNA transcript. The gene regions that remain in the final coding RNA transcript correspond to regions in the genetic code called exons while the regions that are spliced out correspond to gene regions called introns. When scientists first discovered large numbers of spliced-out intron fragments, they were baffled since they originally believed that they served no function and should have been degraded by the cell machinery.
In these newly discovered circular intronic RNAs (ciRNA), the introns are excised from the initial gene transcript into smaller RNA molecules to form circles that enhance the gene’s transcription.
Researchers have actually discovered a wide variety of regulatory RNA molecules that are encoded in gene introns, including small nucleolar RNAs (snoRNA), micro RNAs, and various types of long non-coding RNAs (lncRNA). And now scientists can add ciRNAs to the ever-growing list of functional DNA found in introns, creating a picture of complexity in the cell that will certainly increase in time. Clearly, the intron regions that reside inside genes and cover about 20 percent of the entire human genome are as functionally important to the cell as the protein coding regions (exons) that cover less than 5 percent of the genome." CR
Genes in plants and animals are copied (transcribed) into messenger RNA molecules (mRNAs) that
are subsequently processed to remove segments that do not end up in the mature RNA transcript. The gene regions that remain in the final coding RNA transcript correspond to regions in the genetic code called exons while the regions that are spliced out correspond to gene regions called introns. When scientists first discovered large numbers of spliced-out intron fragments, they were baffled since they originally believed that they served no function and should have been degraded by the cell machinery.
In these newly discovered circular intronic RNAs (ciRNA), the introns are excised from the initial gene transcript into smaller RNA molecules to form circles that enhance the gene’s transcription.
Researchers have actually discovered a wide variety of regulatory RNA molecules that are encoded in gene introns, including small nucleolar RNAs (snoRNA), micro RNAs, and various types of long non-coding RNAs (lncRNA). And now scientists can add ciRNAs to the ever-growing list of functional DNA found in introns, creating a picture of complexity in the cell that will certainly increase in time. Clearly, the intron regions that reside inside genes and cover about 20 percent of the entire human genome are as functionally important to the cell as the protein coding regions (exons) that cover less than 5 percent of the genome." CR
I will praise thee; for I am fearfully and wonderfully made:
Psalm 139:14