In C.elegans, genes necessary for embryogenesis have been identified in several screens (reviewed in Wood, 1988). Later Kempheus et al. 1988, searched for a class of lethal mutations whose function is purely maternal and found that the number of such genes is about a dozen.Among these
him-14 has been identified on LGII, characterized by embryonic lethality, and among the fraction of viable progeny a high incidence of males , suggesting a defect in X-chromosomal non-disjunction. We have been studying members of the kinesin motor protein family (
klp-1 to
klp-15, mostly identified through the genome sequ- encing consortium and Kohara cDNA project), which mediates transport of diverse type of cellular cargo.The microtubule based ATPase kinesin proteins are characterized by amino- terminal motor domain of about 360 aa, followed by a coiled coil domain, and a globular tail domain. However, a novel member
klp-3 (located on cosmid T09A5),has its motor domain located in the carboxy terminal region, and belongs to a special subfamily of kinesin like proteins such as
kar3/ncd and are involved in chromosomal movement.Through germ line transformation experiments we have found that
klp-3 is
him-14 as it can rescue the
him-14(
it44) ts mutant phenotype. Interestingly, when this 9kb genomic fragment was injected in wild type (N2) animals , we obtained a germline transformed line that showed embryonic lethality and resulted in high incidence of males (him) and other developmental defects, sugesting creation of a gain of function mutation. A
klp-3 cDNA clone was obtained from a lambda ZAPII cDNA library (Y. Kohara). Experiments are in pregress to study the temporal and spatial expression of
klp-3 gene using lacZ fusion gene and RNA hybridization experiments. Thus,
klp-3 (
him-14) is the fourth locus, besides
osm-3,
unc-104, and
unc-116 that eccode members of the kinesin gene family. We are studying genetic interactions among these members to elucidate the role of kinesins in development. We thanks genome sequencing consortium and Y. Kohara for valuable assistance.