THE ROLE OF CHROMOSOME ENDS DURING MEIOSIS IN CAENORHABDITIS-ELEGANS

Chromosome ends have been implicated in the meiotic processes of the n ematode Caenorhabditis elegans. Cytological observations have shown th at chromosome ends attach to the nuclear membrane and adopt kinetochor e functions. In this organism, centromeric activity is highly regulate d, switching from multiple spindle attachments all along the chromosom e during mitotic division to a single attachment during meiosis. C. el egans chromosomes are functionally monocentric during meiosis. Earlier genetic studies demonstrated that the terminal regions of the chromos omes are not equivalent in their meiotic potentials. There are asymmet ries in the abilities of the ends to recombine when duplicated or dele ted. In addition, mutations in single genes have been identified that mimic the meiotic effects of a terminal truncation of the X chromosome . The recent cloning and characterization of the C. elegans telomeres has provided a starting point for the study of chromosomal elements me diating the meiotic process.