Worm Breeder's Gazette 13(4): 84a (October 1, 1994)

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.

An additional regulatory sequence for mec-3 establishment

Lili Wang, Jeff Way

Dept. of Biology, Nelson Labs, Rutgers University, Piscataway NJ 08855

Figure 1

  We have identified a sequence in the mec-3 promoter that appears to play an
important role in establishing the pattern of mec-3 expression. If sequences from
-2000 to +500 bp (with the mec-3 start codon as 0) are deleted from our standard mec-3
-lacZfusion, we still observe expression in all the normal mec-3 cells within a few
hours after these cells arise. (We thought this was going to be a negative control.) This
expression is seen in a mec-3 ( u6 )strain, indicating that such expression occurs
during the establishment phase of mec-3 synthesis. The deletions diagrammed
(hatched areas) below indicate that an upstream region between -2000 and -3000
contains sequences for establishment (gray region). (see figure)
  Somehow the presence of this upstream region was missed by both Way et al.
(Genes & Dev. 5, 2199-2211; 1991) and Xue et al. (EMBO J. 11, 4969-4979, 1992). This
was probably because a mec-3 mutant strain can be rescued by a construct lacking the
upstream region. We have found that the conserved Regions I-IV (black boxes in
figure) mediate a low level of mec-3 -independentexpression; since injected DNAs are
often present in high copy, it may be that a low level of establishment expression is
sufficient to make some mec-3 ,which then turns on its own synthesis.

Figure 1