Worm Breeder's Gazette 13(4): 98 (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.

A Defined Set of Lethal Mutations at the Right End of the LGII Cluster.

William G. Kelly, Andrew Fire

Dept. Embryology, Carnegie Institution of Washington, Baltimore, MD.

Figure 1

  The cey-1 gene encodes a DNA binding protein which exhibits specific binding to
two sites in the internal enhancer of unc-54 (1). cey-1 is expressed in oocytes and
ubiquitously in the early embryo, but later becomes restricted to mesoderm (2). This
suggests CEY-1 could play a role in specifying mesodermal patterns of gene
expression. To elucidate the role of cey-1 in normal development, we have pursued
two approaches toward isolating mutations: l) An EMS screen for visible and lethal
mutations in the region of LG II where cey-1 has been physically mapped; and 2) Tc1
-basedscreens (i.e., sending off primers to Ronald Plasterk and Marianne de
Vroomen). This article summarizes the current state of the EMS screens.
  The screens were carried out primarily by cloning wild type F1 progeny of [ unc-4
/ mnC1 males] X [mutagenized unc-4 hermaphrodites]. In these screens, 840 mnC1
-balancedvisible and lethal mutations were recovered from 8954 mutagenized
chromosomes. These mutants were then tested for complementation with mnDf90 .Of
the 840 candidates tested, 84 failed complementation with mnDf90 ;these were then
tested against mnDf87 and mnDp7 .In total, 7 zygotic lethal complementation groups,
but no visible mutations, were found to lie within an m nDF90 / mnDf87 overlap that
lies outside of mnDp77 .The alleles recovered are summarized below.
  Complementation Alleles Phenotype
  Group (Arrest Point)*
  1 cc502 LARVAL (Ll/L2)
  let 852 cc503 LARVAL (L2/L3)
  cc504 LARVAL (L3/L4)
  [ cc520 ]larval
  2 cc505 EMBRYONIC
  let 853 cc506 LEAKY EMBRYONIC
  cc521 larval
  3 cc507 EMBRYONIC
  let 854 cc508 LARVAL (L2/L3)
  4 cc509 LARVAL (Ll/L2)

Figure 1