In the last act of spermatogenesis, competent sperm recognize, bind, and fuse to the oocyte.
fer-14 is a mutant that is defective in this final stage of spermatogenesis. Like the EGF-repeat containing
spe-9 gene,
fer-14 mutant sperm exhibit wild type motility, form a wild type pseudopod, localize to the spermatheca upon insemination into the female reproductive tract, and participate in sperm competition (Singson et al, Genetics 152;201-208, 1999).
fer-14 has been mapped to a .5 map unit interval on the right arm of chromosome I, between
lev-11 and
sur-2 . Various triply marked lines have been contructed for use in polymorphism mapping and this approach has narrowed the
fer-14 containing physical interval down to 40Kb. Utilizing the male/female microarray data from Jiang et al., a candidate gene that is expressed in a strongly sperm-enriched manner has been identified. Efforts are currently underway to generate transgenic lines containing this candidate gene and rescue
fer-14 .
fer-14 shows a unique deficiency complementation pattern to LGI deficiencies. eDf4 and eDf15 appear to have the same left breakpoint. However, eDf4 complements
fer-14 whereas eDf4 fails to complement. Physical mapping of these breakpoints using PCR should further confirm and narrow the physical region containing
fer-14 .
fer-14 is currently defined by one slightly temperature sensitive allele, which when put over a non-complementing deficiency, also has a spe phenotype. We are engaged in a screen for new alleles to unambigously determine the null phenotype for
fer-14 .