TELOMERES IN NEMATODES

Nematode telomeres show the same highly conserved structural features which are observed in other organisms. Cytological and genetic analyse s revealed that nematode telomeres are involved in important meiotic p rocesses, such as the attachment of chromosomes to the nuclear envelop e, the pairing of homologues, the initiation of synapsis and kinetocho re activity during meiosis. The early development of some nematode spe cies is marked by the process of chromatin diminution, which involves developmentally-programmed chromosomal breakage, DNA degradation and n ew telomere formation in all presomatic cells. This large-scale chromo somal heating is mechanistically related to the healing of spontaneous chromosome breaks and is suggestive of the presence of telomerase act ivity. The diversity present in terms of genome organization and chrom osome behaviour makes nematodes an excellent system for the study of m etazoan telomeres.