Junk DNA goodbye!: non-coding RNA cell division control (Introduction)

by David Turell , Wednesday, May 22, 2019, 17:57 (1800 days ago) @ David Turell

Non-coding RNA is necessary to maintain chromosome integrity in cell division:

https://phys.org/news/2019-05-cell-division-requires-non-coding-rna.html

"One chromosomal element that is important for proper chromosome segregation is the centromere, a unique region of DNA on the chromosome that directs chromosome movement during cell division.

"Assistant Professor Dr. Karen Wing Yee Yuen and Postdoctoral Fellow Dr. Yick Hin Ling from the School of Biological Sciences, University of Hong Kong (HKU), discovered that centromeric DNA is used as a template to produce a non-protein coding, centromeric RNA (ribonucleic acid), that is essential for chromosome stability. If there is too much or too little centromeric RNA (cenRNA), the centromere will be defective and chromosomes will be lost.

***

"The DNA of our chromosomes codes for about 20,000 proteins. When the cell needs to produce a particular protein, such as insulin, the segment of DNA molecule coding for insulin, known as a gene, is first used as a template to copy into a RNA molecule. That RNA then serves as a recipe for directing the cells to make the specific protein. However, only 2% of our DNA is protein-coding. Yet, another 70% of our DNA is still copied into RNAs, which are not recipes to make proteins. Those are called non-coding RNA. These non-coding RNAs are once considered as "junk". In recent years, however, researches have revealed vital roles of non-coding RNA, such as in gene regulation and maintaining chromosome structure.

"Dr. Karen Wing Yee Yuen, who leads HKU's Chromosome Biology Laboratory in the School of Biological Sciences, said, "Our current study is performed in single-cell organism, the baker's yeast, but non-coding RNA copied from the DNA of the centromere is also found in multicellular organisms such as humans, mice and flies, suggesting that centromeric RNA (cenRNA) is a fundamentally important molecule that is commonly used by nature to control cell division.'"

Comment: Obviously most of DNA has a purpose.