QUANTITATIVE-ANALYSIS OF CAENORHABDITIS-ELEGANS SPERM MOTILITY AND HOW IT IS AFFECTED BY MUTANTS SPE11 AND UNC54

The sperm of Caenorhabditis elegans translocate in a fashion similar t o sperm of Ascaris suum even though their pseudopods are longer, more plastic in shaper and Form multiple expansion zones around their perim eter. Mutants in spe-11 form primary spermatocytes with a defective pe rinuclear region, but the resulting spermatozoa fan still crawl and fe rtilize eggs. However. the resultant zygotes die due to the absence of sperm-supplied spe-11. Computer-assisted analysis of translocating sp e-11 sperm reveals a novel defect in the dynamic morphology of their p seudopods. A similar anal sis of the C. elegans mutant unc-54, which l acks the most abundant isoform of myosin II, reveals no defect in sper m motility, as expected, since C. elegans sperm have substituted the p rotein MSP for actin in the process of pseudopod expansion. These resu lts reveal an unexpected defect in the dynamic morphology of pseudopod s of spe-11 sperm. This defect, however, does not significantly affect crawling velocity, and it demonstrates how computer-assisted motion a nalysis systems cim reveal subtle behavioral phenotypes in C. elegans mutant spermatozoa. (C) 1997 Wiley-Liss, Inc.