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BIO 335

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Fused tadpoles

John Dilgen, a student a few years ago, attached these two Xenopus tadpoles while they were embryos.

Catalog Description:  BIO 335 - DEVELOPMENTAL BIOLOGY
(S) Examination of the development of select invertebrate and vertebrate embryos plus developmental processes including differentiation, morphogenesis and regeneration. Laboratory observations made as embryos develop from fertilized eggs and surgical operations are performed to observe tissue interactions. Prerequisite: BIO 210. Lecture/Lab Hours: Two lectures, one three-hour laboratory. Fulfills: PRES. (3 cr. hr.)
Frequency code S = offered in spring
Additional frequency code descriptions can be found in the Terminology Guide .

Additional InformationThis is generally a small class of sophomores juniors, and seniors. There are two hour exams, one final and one paper plus lab quizzes and a practical exam.  The course can be taken as Writing Intensive.  While many of the laboratory periods do not run the full three hours, students must be able to return to lab to make observations of their embryos several times throughout the week.

Lecture: The course begins with what is generally called "classical embryology" that describes the early developmental events in a variety of organisms such as sea urchin, frog and chick.  About a week is then devoted to selected events in late embryogenesis such as eye and heart formation.  Turning from this largely descriptive information, we next discuss the regulation of gene activity as it control's development and differentiation.  We then go on to "non-embryological" development.  We focus on organisms such as hydra and Dictyostelium as well as some non-embyrological processes such as regeneration and aging.  Also in this part of the course we discuss the modern molecular understanding of some of the embyrological processes discussed earlier and some additional "model organisms" such as Drosophila and how its segmentation pattern is created.

Double-headed hydra

It is not very difficult to remove a head from one hydra and transplant it on another.

Laboratory:  Students find the laboratory the most exciting part of the course as they can actually observe the dramatic changes occurring in the embryos of sea urchin, frog and chick.  Also, while students have often learned about regeneration experiments before, here they can do their own experiments on planaria, hydra and Dictyostelium and watch regeneration take place.  Some of the experiments are particularly challenging such as trying to perform transplantation and parabiosis experiments (pictured at the top) using frog embryos.  The Lab is scheduled exclusively on Tuesday mornings - and the laboratory is left open - so students can watch the rapid developmental events the rest of the day and the remainder of the week.