We have isolated an allele of
glp-1 that suppresses recombination on the third chromosome between at least
dpy-1 and
dpy-18 9) was generated by gamma-ray mutagenesis and is linked to
e1259. In the strain
dpy-19(
e1259)
glp-1(
q339)/unc-32
(e189)
dpy-18(
e164) we observed that the expected
unc-32 and
dpy-18 recombinants were absent. To investigate this phenomenom further we looked for Dpy and Unc recombinants in strains heterozygous for
e1259q339 and a series of Dpy on Chromosome III:
dpy-1(
e1)
unc-93(
e1500), 500)
dpy-17(
e164), 64)
unc-32(
e189), 89)
dpy-18(
e364) and
dpy-18(
e364)
unc-64(
e246). For each strain six broods were scored The only recombinant found was a single
dpy-18 recombinant in the strain
dpy-19(
e1259)
glp-1(
q339)/dpy-18
(e364)
unc-64(
e246) We think that the suppression of recombination by the
e1259q339 chromosome is specific to Chromosome III rather than a generalized suppression of recombination because
dpy-19(
e1259)
glp-1(
q339)/+ + III;
unc-60(
e723)
dpy-11(
e224)/+ + V animals segregate both
unc-60 and
dpy-11 recombinants at the expected frequency. The
e1259q339 chromosome contains a DNA rearrangement with a breakpoint in the
glp-1 gene (Austin and Kimble this issue) This rearrangment may be the cause of the suppression of recombination Although we have not yet determined the nature of this rearrangment, no dead eggs are laid by
e1259 q339 heterozygotes, suggesting that it is not a reciprocal translocation