Oct. 11, 2012

                                                                                                DHH interpretation


This wild type adult hermaphrodite was prepared for study of cell fates of “undead cells” which failed to undergo programmed cell death in a ced-3 (n717) mutant background.  This mutant allele, isolated in the Horvitz lab, was first described by Ellis and Horvitz in a Worm Breeder’s Gazette article in Jan 1982 and in their paper in 1986.  The TEM study of the adult mutant was conducted at MRC, and aimed to follow the exact cell fates of many “undead cells” (JG White et al., 1991).   This study encompassed four animals, one for the hermaphrodite nose, one for the RVG and anterior ventral cord, another for anterior ventral cord, and one for the posterior ventral cord and tail cells. 


Figures 3 and 4a from the White et al paper come from this specimen, ced-3 RVG, which covers the retrovesicular ganglion and anterior ventral nerve cord.  Among the interesting features within the print set is the “undead cell” P1aap, which is marked as Blue 21 (see region around print #354).  This cell seems to be partway towards a neuronal cell fate, but looks “sick”, with swirling membranous profiles in the cytoplasm.  This cell forms no synapses, although it may receive a few inputs from AVF (compare Figure 3 in White et al).  Figure 3 also plots the axon trajectories and synapses for three other cells noted in the retrovesicular ganglion – possibly representing additional undead cells with cell bodies in this region derived from the P lineages (marked in the print set as Blue 8, 10 and 11).


The anterior ventral cord is vaguely disorganized, such that the command interneurons are less distinctive in size, and many axons from the motor neurons are slightly out of position near the muscle plate.  This complicates the task of assigning exact cell identities in many cases.



HM Ellis and HR Horvitz (1982) On Death and Dying in C. elegans. WBG Vol. 7, No 1, p 67.


HM Ellis and HR Horvitz (1986) Genetic control of programmed cell death in the nematode. Cell 44: 817-829.


JG White, E Southgate and N Thomson (1991) On the nature of undead cells in the nematode Caenorhabditis elegans.  Phil Trans R Soc Lond B 331: 263-71. 


Color codes (most taken directly from John White’s notes)

Red numbers

1          AVB



4          AVA

5          DA1?

6          AVA



9          AVB


Green numbers

1          FLPR





6          AQR?

11        FLPL


Blue numbers

1          VB2?

2          AVF?

3          VB1?

4          AVF?

5          SAB

6          VA1

7          RIF

8          an undead cell,  P cell daughter? (see print 150 and vicinity)

9          DB2?

10        an undead cell,  P cell daughter? (see print 220 and vicinity)

11        an undead cell,  P cell daughter? (see print 230 and vicinity)

12        RIF

13        AVG?

14        RIGR

15        SAB?

16        SAB?

17        DD!

18        DB1?

19        RIGL

20        DA1?  see red 5

21        an undead cell   P1aap  (see print 354 and vicinity)

22        VD1

23        AS1?

24        VD2


Pink numbers

1          VC2?