Simulating Cortical Rotation, Axis Induction, and Experimental Embryology in Amphibian Embryos Using Clay Models

Abstract

The study of development requires learners to understand spatially complex concepts like embryo anatomy. Embryo anatomy is dynamic over time, and it is often manipulated by researchers in experiments that are fundamental to the field. This spatial complexity can be challenging for novice developmental biologists, particularly those who are taught in lecture-only courses that rely heavily on two-dimensional representations of three-dimensional concepts. This article describes a hands-on teaching activity I used in an undergraduate developmental biology course to help students learn about early development in amphibians through the lens of experimental embryology. Students used modeling clay to construct a frog egg and simulate early developmental processes. Students then used the models to recreate the classical embryological experiments that demonstrated the inductive properties of the dorsal organizer and the requirement of cortical rotation for organizer establishment. As students performed the activity, they completed a worksheet to check their comprehension, particularly of concepts that students typically struggle to understand. Data from a survey and pre/post-assessments show evidence of learning gains and positive student perceptions of the lesson. This activity is a simple, inexpensive, and easily replicable way to include hands-on active learning in developmental biology courses and enable students to practice experimental thinking, even in courses without an associated lab