Worm Breeder's Gazette 9(3): 32
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 mutant has been isolated from TR679 which moves very poorly and
shows large scattered paracrystals and mild A-band disorganization
under polarizing microscopy. Both phenotypes are closely linked to dpy-
5(e61)I. The mutation fails to complement unc-13(e450). It interacts
with unc-15 alleles in a complex fashion suggestive of paramyosin
{Figure 1}
The mutation has been designated unc-13(e2153)unc-15(e2153).Unc-15,
the putative structural gene for paramyosin, has been cloned (l) ant
lies at one end of a contig of some 60kb of clonet DNA. Unc-13 is very
close to unc-15 on the genetic map and might be found in the same
contig. Southern blots of restriction digested genomic DNAs from N2,
RW7000, e2153, and sDf6/e73, a balanced deficiency eliminating unc-13
but not unc-15 (2), have been probed with the cosmids COSB12 and C44E1.
COSB12 probing reveals a very weak polymorphic band in sDf6/e73 that
may be a deficiency breakpoint. (Unc-15(e73) is homozygous viable and
dilutes the deficiency chromosome.) C44E1 probing reveals a
rearrangement in e2153. Preliminary restriction analysis is not
consistent with Tc-l insertion, and suggests a deletion, though this
has not yet been proven. A Bristol Eco-R1 fragment of about ~20kb,
absent in e2153, has been cloned into pAST, a pUC-derived plasmid
constructed by Andy Fire that contains the sup-7 tRNA gene.
Experiments aimed at the rescue of unc-13 alleles by transformation
are planned.
The rearrangement in e2153 detected by C44E1 probing may be
independent of its dominant unc-15 associated phenotype. Attempts to
obtain spontaneous revertants in the dissecting microscope have failed.
The two phenotypes of the mutant may also be independent, that
associated with unc-15 arising first and invisibly; however, the
possibility of a cis-acting control element operating at a distance
from unc-15 is intriguing.
{Figure 2}
