Worm Breeder's Gazette 2(2): 14

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.

Sperm Defective Mutants

Y. Argon, S. Ward

We are characterizing 5 temperature sensitive (ts) fertilization 
defective mutants.  These were isolated as ts steriles which lay 
unfertilized oocytes at 25 C.  They all make normal amounts of sperm 
and are rescuable by mating with wildtype males, so their defects are 
in the sperm.  The mutant hermaphrodites lay 150-220 unfertilized 
oocytes at 25 C and a small number (1-6%) of progeny.  tsH4 and tsH3 
lay a small number of defective zygotes as well.  tsH2, tsH3 and tsH4 
lay 30-60 unfertilized oocytes and 160-200 progeny at the permissive 
temperature.  Hermaphrodite sperm are swept out of the spermatheca by 
the oocytes at a rate characteristic of each mutant.
The males of the 4 mutants are sterile as well at 25 C as judged by 
mating them with 25 C grown tsH17 hermaphrodites which do not have any 
sperm.  The male sterility is not due to defective mating because 
sperm are transferred to the uterus of the mated hermaphrodites.  
tsH24 males and tsH1 males stimulate oogenesis in the mated 
hermaphrodites, but tsH2, tsH3 and tsH4 males have so far failed to 
stimulate oogenesis although sperm are transferred.
The temperature sensitive period (TSP) of tsH3, tsH4 and tsH24 has 
been determined.  Although the onset of the TSP varies from 20 to 30 
25 C-hours, they all extend throughout spermatogenesis and end at 44-
46 hrs, slightly after egg laying begins.
tsH24 recovers fertility when shifted from 25 C to 16 C after 
spermatogenesis is finished.  This suggests that the defective gene 
product is reversibly temperature sensitive and is in the sperm.
The sperm of these mutants are being examined by electron microscopy 
to detect fine structural alterations and we hope to analyze them 
biochemically as well.