The primary goal of our lab is to identify and characterize molecules involved specifically in the process of fertilization. Towards this end, we study mutants collectively referred to as the
spe-9-class (named after the first member of this family to be cloned).
spe-9-class mutants produce sperm that are morphologically and functionally indistinguishable from wild-type sperm, except that they are incapable of fertilizing oocytes. This suggests that these gene products are required specifically during the process of fertilization, rather than for some other aspect of sperm development.
spe-13,
spe-19 and
spe-36 are three such
spe-9-class genes that we are currently investigating. We present our functional analysis of
spe-13 that confirms it to be in the
spe-9-class. Two-point, three-point and SNP-mapping data localize
spe-13 to within 1 Mb of the left telomere of chromosome I. We will use a combination of YAC rescue and SNP-mapping to clone this gene. Two-point, three-point, and deficiency mapping data have positioned
spe-19 to the right arm of chromosome V, approximately 11.5 map units from
dpy-21. Further mapping is underway to narrow down the interval within which
spe-19 lies. Again, we will use a combination of SNP mapping and subsequent transgenic rescue via YAC injection to clone this gene. While the functional analysis of
spe-36 is incomplete, the available data strongly suggests that it, too, is a
spe-9-class mutant. We are in the preliminary stages of mapping this gene, and have roughly localized it to position +8 on chromosome IV using a combination of two- and three-point mapping.