WormClassroom

Below is the opportunity for you to lineage the embryo development of C. elegans up to the 8-cell stage. You might want to visit Human Family Tree to start thinking about “lineage.” Also, Embryogenesis of C. elegans can help you make observations of the embryonic development.

Background Information

• A bit of history about the C. elegans cell lineage: When was the whole lineage finished? How was the lineage done?
• The meaning of cell lineage/fate map in development
• Embryo development in 4D: What is a 4D movie? How is a 4D movie generated? Brief tutorial and information regarding the use of VisBio to lineage the 4D embryo development movie.
• WormBase has the information for cell pedigree of C. elegans. See how to use WormBase to find the cell pedigree.

4D Movie Data Set

Most of the movies and images on this site – including the one above – have been compressed to make them easier to download, although compression destroys some of the data in the file. Educators may find smaller files (such as JPG and MOV) easier to work with, while researchers use lossless files (such as TIFF) to retain every pixel of the collected data.

EmbryoCE.zip (290 MB) is a 4D dataset of embryo development up to 8-cell stage. It consists of 12 TIFF files, one for each focal plane. To unzip the file, one can use WinZip (for PC) or Stuffit Expander (for Mac). Once the file is unzipped, it can be read using ImageJ and the Data Browser plugin.

Note: ImageJ and EmbryoCE are real research tools – not instructional materials. As such, their usage is more complex than most files on this site. If you have questions, please contact us.

Questions to Get You Thinking

1. What does the lineage (family tree) look like for each focal plane?
2. Does a cell always have the same neighbors and how important this might be in its development?
3. Why is the cell lineage/cell pattern of lineage the way it is?
4. Does a specific cell always appear at around the same time in every embryo?
5. Which of the daughter cells divides first?
6. Why are two daughter cells unequal size after cell division?
7. Why do the edges of the cells wiggle so much?
8. When is a cell’s fate determined?
9. How are different cell types generated?

Next Steps

Now that you have lineaged the development of an embryo, observe the different types of cells color-coded (PDF ).

Then construct a 4D embryo: A lineaged embryo up to the 100-cell stage gives you the opportunity to observe and construct your own analysis of 4-dimensional embryonic development.