Worm Breeder's Gazette 7(2): 59

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 Contribution to the Genetic Analysis of Amanitin-resistant (amaR) Mutants

A. Fodor, T. Sanford, D. Riddle

In the genetic tests performed thus far, all seven mutants behave 
virtually identically.  All are (at least semi-) dominant and closely 
linked to dpy-13 locus on the linkage group IV.  There is no evidence 
as yet for any maternal effects in the expression of amanitin 
resistance or sensitivity, Heterozygous (ama(R)/+) males were mated 
with dpy-8 odites to test X linkage or 
dominance.  The mated hermaphrodites were cloned in microtiter wells 
in amanitin, The sensitive, self progeny (DpyUnc) did not grow beyond 
the L1 stage, but ama(R) F1 hermaphrodites with normal movement and 
body shape developed to maturity along with the DpyUnc males.  The 
results were the same for each of the seven mutants.  The production 
of resistant (ama(R)/+) hermaphrodite progeny shows that ama(R) is 
dominant.  The production of resistant males shows that it is 
autosomal.  Crosses with strains carrying two linked chromosomal 
markers showed that the ama(R) allele, m118 is not linked to standard 
reference markers on LG I, II or III and V, but it is closely linked 
to dpy-13(IV).  (The chromosomal markers were the following: dpy-3(
DR39)unc-6(e78)(x); 21)unc-3(e151)(x); )
unc-75(e950)(I); )unc-54(e1301)(I); 
unc-4(II); unc-4(II); 
daf-2(e1370)unc-32(III); daf-7 
I); unc-24(IV); 
unc-24(IV); unc-22(IV); 
; dpy11 unc-51(V).) The preliminary two-
factor crosses produced only one dpy-13 ama(R)/dpy-13 + recombinant 
among 100 homozygous Dumpy segregants.  This suggests that ama(m118) 
locus may be within one map unit of dpy-13.  Subsequent crosses 
revealed that all the seven ama(R) alleles are closely linked to dpy-
13.  Three-factor crosses with the m118 in trans to recessive markers, 
+ama(R)+ unc-22, produced three of the four possible classes of 
recombinants: Unc-Resistant, tive, and Dpy-
Sensitive DpyUnc progeny were invariably Sensitive (40/40 tested).  In 
the total of six recombinants, two were obtained in the interval 
between dpy-13 and ama(R), and four recombinants were obtained in the 
interval between ama(R) and unc-22.  Obviously, these data are 
preliminary, however, since all the ama(R) mutants are dominant and 
all appear to be closely linked to dpy-13(IV) we suspect that they all 
may be allelic.