Tests for parental imprinting in the nematode Caenorhabditis elegans

The mutation him-6 (e1423) leads to generalized chromosomal nondisjunction during meiosis in oogenesis and spermatogenesis of C. elegans. As a result, gametes nullisomic or disomic for each of the six chromosomes occur at appreciable frequency. Crosses utilizing marked him-6 strains were used to generate and identify exceptional euploid progeny which had received both homologues of a marked autosome either from the male parent or from the female parent. Examples of all ten possible exceptions were identified and found to be viable and fertile. These results (together with previous data for the X chromosome) indicate that major chromosomal imprinting effects do not occur during gametogenesis in this organism.