The Surprises Will Never Stop

Great catchupIn Circular RNAs Increase Cell Bio-Complexity (5 April 2013) Jeffrey Tomkins makes the arguement we’ve seen so many times even in the last week: something has been found to be biologically functional, therefore “bio-complexity” has increased, therefore design, therefore God.

The specifics are thus not hugely important. DNA can code for a variety of “RNAs” as well as just proteins – the function of these “circular RNAs” is apparently to act as a sponge for another RNA type, microRNAs. It doesn’t strike me as something that would be all that difficult to evolve, I have to say. Here’s a slightly more detailed summary, if you’re still interested. Continue reading

An Exaptated Pseudogene

Appropriately, for this attempt to return to timely updates, the first new DpSU – Pseudogene Plays Important Role in Cell Cycle, by Jeffrey Tomkins – is again related to junk DNA, just as the last one I did was about ENCODE. This article, however, is of the old type – it’s about a genetic feature, once “dismissed as junk DNA,” that has now been shown to have a function. Or, to quote Tomkins:

Once again, DNA sequence that was once thought to be nothing but a genomic fossil has shown itself to be vital to human survival. In this case, if the so-called pseudogene is not functioning properly, cell cycle dysfunction and cancer is the almost certain outcome.

A pseudogene looks like a gene – often another gene in the same organism – but has lost its original protein-coding function. The pseudogene of interest here is called “ψPPM1K,” and is a processed pseudogene. To make such a gene a normal gene (here, PPM1K) is transcribed into mRNA and the introns are stripped out as normal in the process of protein synthesis. However, instead of progressing further the mRNA is transcribed back into DNA which is inserted back into the chromosome. The result is a partial clone of the original gene, generally lacking introns and possibly other parts. Continue reading

piRNA

Today’s DpSU, by Brian Thomas, is called Newly Found Biochemical Is Essential for Life. With a title like that you could be forgiven for concluding that the élan vital had been discovered. However, the implications of the headline seems to oversell the real discovery more than a little. The angle that Mr Thomas is actually going for is, oddly enough, a variation on the most typical anti-Junk DNA argument. Continue reading