Circular Intronic RNAs Defy Junk DNA Dogma | The Institute for Creation Research

Circular Intronic RNAs Defy Junk DNA Dogma

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.1

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.2

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. This was proven when the researchers were able to "perturb" the action of ciRNAs in cells by inhibiting their function and observing the effect on gene expression. The scientists also discovered that the ciRNAs promoted gene function by associating with the transcription machinery that copies DNA into RNA (RNA polymerase II). Interestingly, these ciRNAs were expressed specific to cell-type, further emphasizing that they were specifically controlled and highly functional.1

In contrast to the previously discovered circular RNAs composed of spliced-gene exons and functioning primarily as miRNA (micro RNA) sponges in the cell cytoplasm, ciRNAs act as transcriptional enhancers in the nucleus.3 In fact, ciRNAs are primarily localized to the nucleus, which contains the cell’s genomic DNA, where they enhance gene expression.

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).1 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.1

These newly discovered circular RNAs—embedded inside the non-coding segments of genes—continue to reveal the amazing complexity of the genetic code that exists in multiple overlapping layers of information. These data show that individual genes actually contain many different levels of highly functional genetic information—a fact that gradualistic evolution simply cannot account for.

References

  1. Zhang, Y. et al. 2013. Circular Intronic Long Noncoding RNAs. Molecular Cell. 51: 792-806.
  2. Yang, L. et al. 2011. Genomewide characterization of non-polyadenylated RNAs. Genome Biology. 12: R16.
  3. Tomkins, J. Circular RNAs Increase Cell Bio-Complexity. Creation Science Update. Posted on icr.org April 5, 2013, accessed October 7, 2013.

*Dr. Tomkins is Research Associate at the Institute for Creation Research and received his Ph.D. in genetics from Clemson University.

Article posted on October 9, 2013.

The Latest
CREATION PODCAST
The Secrets of the Cell | The Creation Podcast: Episode 29
Cells are the basic organisms of life and in some groups they are organisms. What is a cell? What goes on inside of a cell? Did all life come from a...

NEWS
Fossil Footprints Fit Flood Ice-Age Model
Anthropologists Thomas Urban (Cornell University) and Daron Duke (Far Western Anthropological Research Group) recently found preserved human footprints...

NEWS
Deep-Sea Lobster Microbiome
Research continues regarding complex and amazing microbiomes found on or within a variety of creatures.1 The microbiome is a microbial community...

NEWS
"Massively Exciting" Fossil Find
Now this is exciting: “Geologists have found the fossil of the earliest known animal predator. The 560-million-year-old specimen is the first of...

NEWS
Copulation Didn't Kill the Frogs, the Flood Did
Evolutionary scientists recently studied 168 frog fossils from central Germany, concluding that the frogs all drowned while aggressively mating. They claim...

CREATION PODCAST
What Can We Learn From Fossils? | The Creation Podcast: Episode...
Is evolution seen in the fossil record? Why are fossilized terrestrial animals found buried with marine creatures? What conditions were needed to form...

NEWS
Be Not Deceived: Spiritually Train to Overcome Secular Science...
Thorough instruction and discipline are the hallmark qualities of a strong military training program. Well-trained soldiers can think on their feet, adapt...

CREATION.LIVE PODCAST
Jurassic World: Dominion - Fun Movie, Bad Science | Creation.Live...
Covered in feathers, running faster than cars, and living in cold climates...these are just a few of the ideas introduced in Jurassic World: Dominion....

NEWS
CET Model in Plants Is Clearly Seen
Plant scientists have known for decades that plants aren’t just static entities. The half-million or more species of plants in the world display...

NEWS
Half-Billion-Year-Old Fossil Brains?
Once again, a recent and remarkable fossil discovery has been made challenging evolutionary theory. A strange arthropod (i.e. a radiodont) has been found...