Chez Charles/ biblio/ Sex determination: primitive Y chromosomes in fish. Edit RecentChanges History Preferences Branchable Charlesworth B. Curr Biol. 2004 Sep 21;14(18):R745-7. A common feature of sex-determination loci is X/Y crossing-over inhibition, followed by divergence, and accumulation of transposons and other repetitive elements the Y locus.