ABSTRACT
The human schistosomes, blood flukes of the Genus Schistosoma, have a large genome estimated to be at least 270 megabase pairs (haploid) in size, arrayed on eight pairs (2 n = 16) of chromosomes including the Z (male) and W (female) sex chromo somes. The genome appears to include about 14,000 protein encoding genes and a large amount of repetitive sequences. Much of this repetitive component of the schistosome genome is com prised of mobile genetic elements. Of these elements, an expanding number of discrete long terminal repeat (LTR) retrotransposons have been identified in the past five years. The identity, structure, phylogenetic relationships, and size contributions of these schistosome LTR retrotransposons are reviewed here. These elements include the gypsy-Yike or Pao! BEL -like retrotransposons Boudicca, Sinbad, fiigitive, Saci-1, Saci-2, and Saci-3 from Schistosoma mansoni and Gulliver from Schistosoma japonicum .
