Growing a tail: cellular and genetic determinants that diversify tail proportion in mammals

The axial skeleton provides a framework for diverse mammalian tail forms and functions, including various means of locomotion and communication. Extreme differences between species, such as the number and proportion of vertebrae, suggest the mammalian tail is highly evolvable, perhaps in large part due to its modular development and organization. Aspects of tail diversification are evident in the laboratory mouse and the bipedal lesser Egyptian jerboa, which diverged from a common ancestor about 50 million years ago. Despite having fewer vertebrae, the jerboa tail is 1.5-times longer than the mouse tail when normalized to body length due to disproportionate elongation of individual vertebrae. Using µCT imaging and tissue histology of mouse and jerboa skeletons, we found that the initially similar neonatal tails diverge during a juvenile phase of disproportionate growth that is more rapid in jerboas. We show that disproportionate elongation is correlated with differences in proliferation and growth zone heights in vertebral growth cartilage and that the cranial and caudal growth plates do not contribute equally to longitudinal growth. Ongoing work will identify the molecular mechanisms responsible for the development and evolution of axial skeletal proportion in mouse and jerboa, which will form a basis to more broadly understand diversification of mammalian tail skeletal proportion. 

@inproceedings{weber2024growing,
  title={Growing a tail: cellular and genetic determinants that diversify tail proportion in mammals},
  author={Weber, Ceri and Gacasan, Erica and Weitzel, Alexander and Moore, Talia and Sah, Robert and Cooper, Kimberly},
  booktitle={INTEGRATIVE AND COMPARATIVE BIOLOGY},
  volume={64},
  pages={S547--S547},
  year={2024},
  organization={OXFORD UNIV PRESS INC JOURNALS DEPT, 2001 EVANS RD, CARY, NC 27513 USA}
}