Abstract
This whimsical case introduces students to the topic of dorsal/ventral (DV) axis formation in amphibians. After the recent birth of a good-sized clutch of eggs, Heather Pipiens is pleased to see that most of her little larvae are doing fine, but alarmed to find that one has a smaller head and hasn't yet formed adhesive glands. Mr. Pipiens attempts to comfort his wife by noting that not all of their 133 healthy larvae developed at the exact same rate: "Remember Gracie? She gastrulated almost a day later than the rest and she's just fine." As the story unfolds, students learn how induction and cytoplasmic determinants coupled with other molecular mechanisms contribute to the formation of the DV axis and the embryonic body plan. Students are introduced to the basics of DV axis formation, how the organizer and Nieuwkoop center are formed, and how various genes interact to facilitate the formation of the DV axis in amphibians. The case was originally written for a course in developmental biology.