Medical Research Council - London Institute of Medical Sciences

Now in our 11th year of bringing you beautiful imagery from biomedical science every day

Switched Off

Small non-coding RNA sequences called piRNAs regulate genes involved in germ cell development

20 June 2022

Switched Off

Hidden within our genome are sequences of DNA called transposable elements (TEs) that can move between locations, and potentially disrupt key genes. Our germ cells – precursors of eggs and sperm – have evolved a defence in the form of piwi-interacting RNAs (piRNAs), which silence TEs. But whether piRNAs also silence genes involved in producing germ cells was unclear. Using the nematode worm as a model, researchers found that piRNAs silenced genes involved in sperm formation. In worms with mutated non-functioning piRNAs (bottom), there were more germ cells expressing genes linked to creating sperm (red) compared to a ‘normal’ worm (top). As these worms are hermaphrodites, they need this ‘switch off’ of sperm production to be able to start making egg cells (yellow). This study shows that piRNAs could have wider roles in humans beyond simply silencing TEs.

Written by Sophie Arthur

Search The Archive

Submit An Image

What is BPoD?

BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

Read More

BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.