Tapeworm stem cells drive growth and regeneration. Image credit: Tania Rozario (CC BY 4.0)
Many worms have remarkable abilities to regrow and repair their bodies. The parasitic tapeworms, for example, can reach lengths of several meters and grow much more quickly than tissues in humans and other complex animals. This growth allows tapeworms to counteract the continual loss of the segments that make up their bodies, known as proglottids – a process that happens throughout their lives.
The capacity to regenerate thousands of lost body segments and maintain an overall body length suggests that tapeworms have groups of stem cells in their body which can grow and divide to produce the new body parts. Yet, regeneration in tapeworms has not been closely studied.
Rozario et al. have now examined Hymenolepsis diminuta, the rat tapeworm, and identified the neck of the tapeworm as crucial for its ability to regrow lost body segments. Further analysis identified two genes, zmym3 and pogzl, that are essential for cell division during tapeworm growth. However, Rozario et al. showed that these genes are active elsewhere in the worm’s body and that it is the conditions found specifically in the tapeworm’s neck that create the right environment for stem cells to enable regeneration of new segments.
Tapeworms provide a valuable example for studying the growth of stem cells and these findings highlight the important role that the cells’ surroundings play in driving stem cell activity. These findings could also lead to new insights into how stem cells behave in other animals and could potentially lead to new approaches to prevent or treat tapeworm infections.
