Zoe Harrington: Metamorphosis of Movement: Quantifying locomotion to define tail-to-limb neural circuit transformation in the Xenopus frog

BCCN Berlin / Technische Universität Berlin

Abstract

 

 

Movement is the foundation of all sophisticated behavior and the final output of motor neurons. To link motor cell types and circuits to their output, a comprehensive, quantified collection of movement features is required. With an atlas of the wildtype movement repertoire, comparison with mutant animals makes it possible to reveal associations between modified cell types or structures and alterations in movement patterns – thus establishing cell type-circuit-movement connections. Xenopus laevis, like other frog species, undergoes a metamorphosis of its movement repertoire during development. During its metamorphic transition from tadpole to frog, the tail degenerates and the fore- and hindlimbs develop. Consequently, its locomotor strategy changes from undulatory swimming to limb-based locomotion (walking, hopping, scratching, crawling). Frog metamorphosis offers a unique opportunity to study how two motor circuits and modes of movement in one animal differ and how they may interact. To gain a better understanding of how tail and limb-based locomotion strategies develop and are coordinated during early metamorphic stages, this thesis focuses on optimizing computational methods for tadpole pose estimation and quantitative behavior analysis. We develop a complete imaging setup, record an assay of wildtype Xenopus throughout metamorphosis, and use SLEAP for multi-animal pose estimation. Our kinematic analysis of tail and hindlimb movements quantifies the metamorphic switch between tail and hidlimb-based locomotion. Future work will build upon these advances by using the pose estimation and analysis pipeline in place for comparison with various mutant Xenopus animals.

 

Additional Information

Master Thesis Defense

 

Organized by

Prof. Dr. Lora Sweeney (IST Austria)   & Prof. Dr. Susanne Schreiber   / Lisa Velenosi