Worm Breeder's Gazette 10(2): 29

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.

Molecular Cloning of fem-1

Andrew M. Spence

Figure 1

The fem-1 gene is essential for all aspects of male development and 
for spermatogenesis in the hermaphrodite in C.  elegans (Doniach and 
Hodgkin.  Dev.  Biol.  106:223.1984).  It is located 0.03 m.u.  to the 
right of unc-5 on LGIV.  The figure summarizes the present state of 
the contig which I described in the last WBG (10#1:33) and which now 
contains both unc-5 and fem-1.[See Figure 1]
The orientation of the contig on the genetic map is established by 
two polymorphisms, eP14, and eP60, present in strain CB3724, which is 
congenic between N2 and N62 over the unc-5 - mor-2 interval, and which 
was constructed by T.  Doniach.  eP14, as I mentioned in the last WBG, 
maps to the left of unc-5, while eP60, detected by cosmid C26E7, maps 
to the right.  [One of 16 recombinants in the unc-5-mor-2 interval 
separated eP60 from unc-5(+)].  Between these two polymorphisms are 
located several which cosegregate with various unc-5 alleles [eg.  
eP27 with unc-5(bx8), eP52 with unc-5(st1003)].  Cosmid C26E7, and the 
overlapping clone C17E1, detect a polymorphism, eP58, in the X-ray-
induced allele fem-1(e2044).  eP58 cosegregated with e2044 in 15 of 15 
recombinants in the fem-1-mor-2 interval.  A 15 kb fragment from the 
region of overlap between these two cosmids reveals not only eP58 but 
also polymorphisms in each of three [32P]-induced fem-1 alleles, e2365,
e2365, and e2382.  The same 15 kb probe detects two transcripts of 
about 3 kb and 2.7 kb in mixed populations of either N2 hermaphrodites 
or him-8 hermaphrodites and males.  I am presently locating the fem-1 
polymorphisms and these transcripts more accurately in the hope of 
identifying one or both transcripts as products of fem-1.  Cosmid 
C17E1 is able to transform fem-1 XX females into self-fertile 
hermaphrodites.   I injected females of the genotype fem-1(e2044)mor-2(
e1125).  e2044 being a putative null allele of fem-1, and mated them 
with fem-1(hc17ts) males raised at 15 C.  The F1 were raised at 25 C, 
at which temperature the XX animals develop as females and the XO 
animals as sterile intersexes unless transformed to fem(+).  I 
obtained five rescued F1,and from the progeny of three I was able to 
start lines homozygous for each of the two fem-1 alleles.  The 
rescuing DNA is transmitted as an unstable duplication in each line.  (
See the note by Hope et al.  in this issue for a summary of the 
injection results.)  I have not yet measured the fertility of the XX 
hermaphrodites in these lines, but it is lower than wild-type at 25 C 
At least some of the XO animals appear to be normal males, but I have 
not tested their fertility.  I intend to define the extent of the fem-
1 locus more accurately by repeating the transformation experiments 
with smaller DNA fragments from the region in which the fem-1 
polymorphisms reside.

Figure 1