Human genetics just got a whole lot more complicated with a report published last week by Isidore Rigoutsos’ team in Oncotarget. As if differences in expression profiles between cells, tissues and differentiation stages weren’t already enough, it seems that race and gender also affect genomic output.
Specifically, the team focused on transfer RNAs (tRNAs). tRNAs may seem like unassuming molecules to some, with a dull factory-floor job in the production line of proteins. However, they can give rise to shorter tRNA fragments (tRFs) through cleavage, and while it is still unclear what these molecules actually do, they have been shown to affect many physiological processes, including cell growth and response to DNA damage.
They have been found in all corners of life, from bacteria and archaea to yeast and mammals, but they have not yet been extensively catalogued in humans.
The common dogma has been that transfer RNAs (tRNA) are simple, passive adapter molecules bringing together the nucleic acid code of messenger RNA (mRNA) and the amino acids of proteins.
But now we are seeing that fragments of tRNA may be very important for gene regulation and other biological processes. We don’t know exactly how yet but that is what makes science fun.
It also indicates that our current understanding of genomic processes may well be skewed because of different non-genomic processes between different populations. It may be that while the genomic differences between groups are slight, the effects of non-genomic processes, such a tRNA fragments, might have real impacts on human health.
We shall soon find out.
Image: eLife – the journal