A link between two lice that solves an itchy mystery

Did you ever think that lice could also attack your body? Head lice are not quite the same as body lice. Scientists have scratched around for an answer over the years, but previous genetic studies neglected to locate any significant contrasts between the two sorts of lice.

People hear the word “lice” and get hysterical! It is really an unpleasant and annoying problem to go through!

Interestingly, head lice are not all that bad. Surely, they are highly communicable parasites to humans, but they are harmless. While, on the other hand, body lice are the “bad ones” that transmit bacteria and spread diseases such as typhus or trench fever. This clear distinction shows that there is an itchy mystery to be solved.

Dr. Araxi Urrutia, a researcher at the University of Bath, and her cooperation of wise scientists bring confirmation of this mystery, in spite of the fact that the genes of the two lice appear to be same, through a key molecular mechanism called alternative splicing. Alternative splicing is a post-transcriptional modification in which a single gene can code for multiple proteins. When the pre-mRNA transcribed from one gene is spliced to different mRNAs, they are expressed to make proteins with distinct structural and functional properties. Thus, at this point, the single gene has increased its coding capacity and alternative splicing acts an important source of protein diversity. This process provided the first evidence of the differences, identifying that the genes were spliced differently in the two types of lice because of the way the two lice processed RNA differently, giving rise to two functional proteins.

It is obvious that head and body lice differ markedly in their genotypic traits. However, there are yet phenotypic differences to be explored, which show how body lice adapt to clothes. Surprisingly, body lice are a recent evolutionary innovation and because of this, head lice, a common feature we possess as humans, has given rise to body lice through alternative splicing. Dr. Urrutia found evidence of alternative splicing in the salivary glands and the upper feeding tract of body lice. This might suggest why the body lice adapted to live in a new habitat by the use of clothing and bad hygiene.

The mechanism of alternative splicing is more widespread than initially thought. It involves an opportunity for gene regulation and an expansion for protein diversity. This particular study provides alternative splicing with additional utility of evolutionary flexibility, analysing how lice were able to evolve and adapt rapidly to different environments. In order to gain more insight into the molecular differences between the two lice, the research must be further explored as the first evidence of the genes showing differences in RNA processing needs prove whether the lice are two completely separate species.

This remarkable study of the link between head and body lice stems from the newly developed University of Bath’s Milner Centre of Evolution. This centre is an illuminating venture anticipated for world-class evolutionary science research in the UK. Scientists conduct new, innovating research because it could help our society to become more aware about how diseases are spread so easily.

As for now, maintain impeccable hygiene and be aware there is such a species as body lice and not just the ones that live within our hair!

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