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
COVID-19
Some Fake Coronavirus News Used to Spread Malware
As a systems administrator, I see thousands of emails come in where someone is trying to get a user to click on a link. A lot of these are just plain old...

NEWS
Traces of "Oldest Ancestor" Found
A new study released on March 23, 2020, claims that evolutionary scientists have identified the oldest human ancestor. The fossil evidence for this assertion...

COVID-19
Three Positives from COVID-19
Coronavirus (COVID-19) is no surprise to God. God knew about this pandemic before the dawn of His creation. Some people may question why God allows such...

COVID-19
The Gospel and COVID-19
It is obvious that life in America, and most parts of the world, has drastically changed in the last few months due to the novel coronavirus. Whether we...

COVID-19
A Time for Firsts Amid COVID-19
All of us have experience with firsts, and today is no exception as America sails through the uncharted waters of the coronavirus pandemic (COVID-19)....

COVID-19
What’s the Difference Between Virus and Bacteria?
As we are embroiled in a worldwide COVID-19 pandemic, it is important to know the basics of these tragic viral infections and why the medical community...

NEWS
ICR Beginning Search for a New President
As was noted in my article “Biblical Succession” in the April issue of Acts & Facts, the ICR Board of Trustees has authorized a national...

COVID-19
Potential Coronavirus Treatments Enter Large Clinical Trials
Some good news in potential treatment options for COVID-19 was reported in the American journal Science.1 Four new treatment options were being...

NEWS
Yellowstone Supervolcano Unlikely to Blow
For several years, secular scientists have been predicting a possible supervolcano eruption at Yellowstone National Park. Recently, the London Daily Mail...

NEWS
Deep Water Squid Communication Mystifies Scientists
In the deep, dark, cold waters of the Pacific Ocean—about 1,500 feet below the surface— hundreds of Humboldt squid the size of small humans...