Chloroplast protein and centrosomal genes, a tRNA intron, and odd telomeres in an unusually compact eukaryotic genome, the cryptomonad nucleomorph.

ABSTRACT: Cells of several major algal groups are evolutionary chimeras of two radically different eukaryotic cells. Most of these "cells within cells" lost the nucleus of the former algal endosymbiont. But after hundreds of millions of years cryptomonads still retain the nucleus of their former red algal endosymbiont as a tiny relict organelle, the nucleomorph, which has three minute linear chromosomes, but their function and the nature of their ends have been unclear. We report extensive cryptomonad nucleomorph sequences (68.5 kb), from one end of each of the three chromosomes of Guillardia theta. Telomeres of the nucleomorph chromosomes differ dramatically from those of other eukaryotes, being repeats of the 23-mer sequence (AG)(7)AAG(6)A, not a typical hexamer (commonly TTAGGG). The subterminal

SUBMITTER: Zauner S 

PROVIDER: S-EPMC26640 | biostudies-literature | 2000 Jan

REPOSITORIES: biostudies-literature