Topic: Frog metamorphosis

The Xenopus laevis frog shows a wide range of motor behaviors during metamorphosis, transitioning from tail-based escape swimming, to free swimming, and finally, limb-based movement. This swim-to-limb transition allows us to study in a single organism how motor and interneurons in the spinal cord generate these behaviors. Here, utilizing advances in genetic manipulation and behavioral tracking, we dissect the molecular features and contribution of each spinal cord cardinal class to swim versus limb behavior over frog metamorphosis.We devise a high-throughput CRISPR screen, in which we knock ou

As tadpoles switch from undulatory to ambulatory locomotion a repeated array of axial swim units transitions to a limb-torso-limb architecture along the rostrocaudal axis. Exemplifying this, at early tadpole swim stages, motor neurons of a single type are evenly distributed along the spinal cord. While, at later frog stages, level-specific motor columns are added at both thoracic and limb levels. Here, we show rostrocaudal differences in inhibitory and excitatory interneuron populations emerge during frog metamorphosis. This raises the question of when differences in neuronal architecture dev