The longstanding question of how animals and their organs reach a defined size is fundamental to developmental biology. Planarians offer an intriguing model, as they can dramatically change their body size throughout life, in response to nutrient availability or when regenerating. This body size regulation depends on balancing cell proliferation and cell death, but its molecular regulation remains incompletely understood. Now, Teresa Adell and colleagues identify a novel gene family that regulates body size in the planarian Schmidtea mediterranea. In a screen for genes involved in eye regeneration, the authors identify Blitzschnell (bls; ‘quick as a flash’ in German), the loss of which causes faster regeneration. bls belongs to a gene family encoding putatively secreted peptides that are found only in the planarian order Tricladida. Three bls subfamilies are expressed in secretory prepharyngeal cells, and their coincident knockdown after dsRNA treatment promotes faster regeneration via increased cell division and decreased mitosis. During starvation-induced body shrinkage, bls knockdown does not change overall body size, even though total cell number is increased; rather, cell size is reduced in this condition. Finally, bls expression is downregulated following nutrient intake, and genetically interacts with the evolutionary conserved insulin/Akt/mTOR metabolic network. The de novo evolution of the bls gene family in the Tricladida lineage may have provided an additional mechanism to restrict cell number in these very plastic animals.
Quick as a flash: regulating planarian body size
Quick as a flash: regulating planarian body size. Development 1 April 2020; 147 (7): e0703. doi:
Download citation file:
Advertisement
Cited by
Call for papers: Uncovering Developmental Diversity
Development invites you to submit your latest research to our upcoming special issue: Uncovering Developmental Diversity. This issue will be coordinated by our academic Editor Cassandra Extavour (Harvard University, USA) alongside two Guest Editors: Liam Dolan (Gregor Mendel Institute of Molecular Plant Biology, Austria) and Karen Sears (University of California Los Angeles, USA).
Choose Development in 2024
In this Editorial, Development Editor-in-Chief James Briscoe and Executive Editor Katherine Brown explain how you support your community by publishing in Development and how the journal champions serious science, community connections and progressive publishing.
Journal Meeting: From Stem Cells to Human Development
Register now for the 2024 Development Journal Meeting From Stem Cells to Human Development. Early-bird registration deadline: 3 May. Abstract submission deadline: 21 June.
Pluripotency of a founding field: rebranding developmental biology
This collaborative Perspective, the result of a workshop held in 2023, proposes a set of community actions to increase the visibility of the developmental biology field. The authors make recommendations for new funding streams, frameworks for collaborations and mechanisms by which members of the community can promote themselves and their research.
Read & Publish Open Access publishing: what authors say
We have had great feedback from authors who have benefitted from our Read & Publish agreement with their institution and have been able to publish Open Access with us without paying an APC. Read what they had to say.