Summary: being transparent and amenable to laboratory manipulation, C. elegans cell lineage was first completed by John Sulston in 1980s. Cell lineage is similar to the family tree of cells. The development of a cell's predecessor and successors can be determined from the lineage.

Cell Lineage of C. elegans

A Bit of History: ---- "but it sufficed to get us started in earnest on the cell lineage. The significance was that although Sydney had wanted from the beginning of the project to follow cell lineages, it was presumed that the most interesting development happened in the egg. So this was the only stage that had been studied, but it was proving very difficult to see anything. It meant, however, that there were already Nomarski DIC (differential interference contrast) microscopes in the lab. ----Seeing my first cell division was an exciting moment, because it implied that determining the larval lineage was possible (Figure 4). (p. 2)"
The transparency of the C. elegans made the lineaging possible.
A complete cell lineage: of C. elegans can be found (click on the image to see the whole lineage).
"The Cell lineage is the description of the history of each embryonic cell, beginning with the un-cleaved egg. The products of every division are traced until the rudiments of the embryonic organs become distinct. (Ways of Knowing by John Moore p. 494)". As the complete cell lineage shows, from top to bottom, you can see an un-cleaved, just fertilized zygoteG, P0 cell divides into two daughter cells (AB and P1 cells) . The two daughter cells then divide into more daughter cells that eventually form a map and enable one to trace a cell's predecessors and successors.
Time Spent: Dr. John Sulston spent one and a half years (in the dark) to complete C. elegans cell lineage.
Hand drawn: Dr. Sulston hand drew the real time worm development. The C. elegans embryoG development wasn't recorded in video for lineaging, it was all done by hand.
Microscopy Used: Nomarski Optics (also known as Differential Interference Contrast (DIC) microscope) was used.
Image Generated:
(a one-cell embryoG with paternal and maternal pro-nucleiG meeting in the center)

Sample Lineaging:
(click on the image to observe the embryonic development from 1-cell to 100-cell)

Research Questions

1) What is derived from each cell?

2) Do cells from the same mother cell behave the same?

3) Do cells migrate after they are born?

4) Do all C. elegans embryos develop in the same pattern? Is this true for all organisms?

5) Do neighbor cells affect the development of a cell?

More about C. elegans cell lineage

The C. elegans Cell Lineage Module: instructional materials for teaching cell lineage by inquiry. Resources can be used/adapted for teaching disciplines (e.g.: developmental biology, cell biology, genetics) with other instructional approaches (e.g.: lectures, lab) as well. Animations, movies, images and hands-on tools are included.

Credits:

1. Cell Lineage: The embryonic cell lineage of the nematode Caenorhabditis elegans, retrieved 12/10/04, from http://www.wormatlas.org/Sulstonemblin_1983/toc.html.

Glossary:

Embryo: the early developmental stage of an organism (C. elegans in this case) after fertilization and before hatching.

Pro-nuclei: one of two haploid nuclei in a newly fertilized embryo (one maternal and one paternal) (Adapted from The Cell - A Molecular Approach. Geoffrey M. Cooper 1997)

Zygote: a fertilized egg; diploid cell resulting from fusion of a male and female gamete. (Molecular Cell Biology/Harvey Lodish [et al.] - 4th)