Understanding the size dependency of the reproductive system in Schmidtea mediterranea

Abstract

Planarians show high developmental plasticity and many aspects of their physiology are size dependent. The formation of its reproductive system is very unique among organisms as it in develops only after the planaria reach a particular length. This is an indication of the planarians being “aware” of their size and the presence of a size sensing mechanism. Based on prior lab research, we investigate into one such identified pathway, the activin signaling pathway in Schmidtea mediterranea . We try to look into the known components of the activin signaling pathway and some potential other ligands and try to elucidate their expression patterns. Such expression patterns provides us with better insights of all these components and further help to explain and understand the signaling pathway. Further we investigate the inhibition of activin in the system as well as its upregulation and how it affects the overall development of the reproductive structures. Our results show that indeed in absence of activin ligands, the planaria fail to grow sufficiently and further fail to develop the reproductive structures. This could hint at the potential role of activin signaling in the development of the reproductive system in Schmidtea mediterranea.