Worm Breeder's Gazette 3(1): 26

These abstracts should not be cited in bibliographies. Material contained herein should be treated as personal communication and should be cited as such only with the consent of the author.

Morphological Development of TS Embryonic-arrest Mutans

J. Miwa, E. Schierenberg, G. von Ehrenstein

We have been analyzing the lineage and morphology of ts embryonic-
arrest mutants.  It is possible to classify the mutants into four 
major groups according to their lethal 
phenotype:
1.  mutants arrested before the first division,
2.  mutants arrested during the proliferation period (1-cell to 
around lima bean stage with ca.  540 cells ),
3.  mutants arrested around the lima bean stage, the beginning of 
morphogenetic period,
4.  mutants arrested during morphogenesis (lima bean stage to 
hatching ) .
The majority of the mutants studied belong to the 3rd group.  
Interestingly, all the mutants of this group have visible 
morphological abnormalities much earlier (before about the 80-cell 
stage) than at their arrested stage.  Parameters such as cell division 
axes, division rhythm of stem cell groups, and size of sister cells 
are essentially invariant in the wild-type embryo (1) .  One or more 
of these parameters are affected in the mutants of the 3rd group.