Worm Breeder's Gazette 8(3): 53

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.

A Mutation Affecting the Migrations of Many Cells

E. Hedgecock

Figure 1

Mutations in several genes have been identified that affect the 
migrations of particular classes of cells.  For example, vab-8 (LGV) 
mutations disrupt the embryonic migration of the CAN cells from their 
origin in the head to their final position over the gonad primordium (
Sulston and Hodgkin, Newsletter vol.  5.  No.  1, p.19; Manser and 
Wood, ibid vol.  8, No.  2, p.9).  Mutations in other genes affect the 
migrations of the HSN neurons, the Q neuroblasts, and the sex 
mesoblasts.  Many of these mutants are pleiotropic but none suggest a 
common component to all cell migrations.
A recessive mutation, mig(rh17), on linkage group X disrupts the 
migrations of many classes of cells.  In particular, embryonic neurons 
ALM, CAN, and HSN are all found displaced partway toward their 
positions of birth.  The postembryonic migrations of neurons (AVM, AQR,
PQR, SDQR) derived from the Q neuroblasts are similarly affected.  
The embryonic coelomocytes are displaced anteriorly and the 
postembryonic movements of the sex mesoblasts are sometimes abnormal.  
A small fraction of the animals have pale, thin tails.  A similar, but 
more severe, phenotype occurs in vab-8(e1017) mutants where it has 
been attributed to defective CAN migration (Sulston and Hodgkin loc 
cit).  The rh17 mutants are also defective in egg-laying presumably 
because the HSN is displaced.  The embryonic migrations of the gonad, 
the M mesoblast and its homologue (mu int R) are apparently normal.  
As the migrations affected by rh17 are reduced in extent but not 
abolished, conceivably the null phenotype is more severe.
Typical cell positions for some of the affected cells in wild type 
and mig(rh17) mutants are shown 
[See Figure 1]

Figure 1