Worm Breeder's Gazette 13(5): 42 (February 1, 1995)

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.

Toward cloning pag-3

Yiwen Jia and Eric Aamodt

Department of Biochemistry and Molecular Biology, Louisiana State
University  Medical Center, Shreveport, LA 71130-3932

      At the last worm meeting, we reported that the pag-3(ls20) allele
causes  ectopic mec-7lacZ fusion gene expression in the BDU neurons.
(Thank you Joe  Culotti and Michel Hamelin for mec-7lacZ.)  The touch
neurons express mec-7 and  the BDUs are lineal sisters of the ALM touch
neurons.  The pag-3(ls20) mutation  has two other phenotypes: a reverse
kinker Unc phenotype and variable axonal  guidance defects in the touch
neuron and BDU axons.  The BDU neurons in a  pag-3(ls20) mutant also
express the endogenous mec-7 gene at roughly the same  level as the touch
neurons, which we detected with an anti-MEC-7 antibody (thank you Marty
Chalfie and Cathy Savage).  The BDU neurons of a pag-3(ls20) mutant  did
not appear to express  mec-3lacZ but strongly expressed a mec-4lacZ fusion 
gene (thank you Monica Driscoll).
      We hope to clone pag-3 by transformation rescue.   Based on
deficiency mapping  and three factor crosses, pag-3 is located on the
right arm of the X-chromosome  between unc-3 and unc-7 (figure).  YAC
Y37H4 rescued both the Unc and  misexpression phenotypes but all of the
cosmids shown failed to rescue  pag-3(ls20) mutants.   We are currently
subcloning pag-3 from Y37H4 by making  nested deletions and by making a
phage library from the YAC.