adenine

I do not expect aliens to have guanine, adenine, etc. as their storage device, but that's not to say they won't have one.

And then the functional group attached to be 1' carbon, that's also similar to adenine.

If a modified uracil complements an adenine in tRNA, it will complement an adenine in the RT primer or an adenine being added to it.

Researchers injected a chemical called nicotinamide adenine\n dinucleotide, or NAD, which reduces in the body as we age. \n The addition of this compound led to the radical reversal\n in the ageing of the mice.

Sure, components may be the same, but so is guanine, adenine, thymine, and cytosine, yet these components make so very different creatures. I think your opinion is valuable, but getting more data is required: have you shown that project to your target audience?

Ethanol, ribose, glycine, adenine, and others, for example. The overall nature of life in the Universe may prove to be quite a surprise to us humans but for now the overwhelming scientific consensus is that carbon based chemistry is by far the most likely route for life to develop anywhere.

The authors find that methyl-adenine seems to play a role opposite to methyl-cytosine, surprisingly. While the existence of methyl-adenine was known in bacteria, its function in gene expression in more complicated organisms was not known. Refs 1-3 don't show a causative role for methyl-adenine in increasing gene expression but the correlations the authors report are likely to be followed up.

But then, there many other genetic regulatory mechanisms that can do that as well - such as histone modifications, chromatin structure, transcription factors, and probably methyl-adenine too! All these mechanisms interact to ensure genes are turned on and off at the right time and place, and this field is known as 'epigenetics'. Methyl-cytosine is a modified version of cytosine that is a very important part of epigenetics, but since it is almost irrelevant to other aspects of genetics, I would argue that you could not consider it a 'fifth base'. Having read the paper, methyl-adenine is the same - interesting new aspect of epigenetics and gene regulation, but not a new base. Also, this paper doesn't exactly 'discover' it, we found methyl-adenine in bacteria in the 60s...